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  • C#/.NET Little Wonders: Comparer&lt;T&gt;.Default

    - by James Michael Hare
    I’ve been working with a wonderful team on a major release where I work, which has had the side-effect of occupying most of my spare time preparing, testing, and monitoring.  However, I do have this Little Wonder tidbit to offer today. Introduction The IComparable<T> interface is great for implementing a natural order for a data type.  It’s a very simple interface with a single method: 1: public interface IComparer<in T> 2: { 3: // Compare two instances of same type. 4: int Compare(T x, T y); 5: }  So what do we expect for the integer return value?  It’s a pseudo-relative measure of the ordering of x and y, which returns an integer value in much the same way C++ returns an integer result from the strcmp() c-style string comparison function: If x == y, returns 0. If x > y, returns > 0 (often +1, but not guaranteed) If x < y, returns < 0 (often –1, but not guaranteed) Notice that the comparison operator used to evaluate against zero should be the same comparison operator you’d use as the comparison operator between x and y.  That is, if you want to see if x > y you’d see if the result > 0. The Problem: Comparing With null Can Be Messy This gets tricky though when you have null arguments.  According to the MSDN, a null value should be considered equal to a null value, and a null value should be less than a non-null value.  So taking this into account we’d expect this instead: If x == y (or both null), return 0. If x > y (or y only is null), return > 0. If x < y (or x only is null), return < 0. But here’s the problem – if x is null, what happens when we attempt to call CompareTo() off of x? 1: // what happens if x is null? 2: x.CompareTo(y); It’s pretty obvious we’ll get a NullReferenceException here.  Now, we could guard against this before calling CompareTo(): 1: int result; 2:  3: // first check to see if lhs is null. 4: if (x == null) 5: { 6: // if lhs null, check rhs to decide on return value. 7: if (y == null) 8: { 9: result = 0; 10: } 11: else 12: { 13: result = -1; 14: } 15: } 16: else 17: { 18: // CompareTo() should handle a null y correctly and return > 0 if so. 19: result = x.CompareTo(y); 20: } Of course, we could shorten this with the ternary operator (?:), but even then it’s ugly repetitive code: 1: int result = (x == null) 2: ? ((y == null) ? 0 : -1) 3: : x.CompareTo(y); Fortunately, the null issues can be cleaned up by drafting in an external Comparer.  The Soltuion: Comparer<T>.Default You can always develop your own instance of IComparer<T> for the job of comparing two items of the same type.  The nice thing about a IComparer is its is independent of the things you are comparing, so this makes it great for comparing in an alternative order to the natural order of items, or when one or both of the items may be null. 1: public class NullableIntComparer : IComparer<int?> 2: { 3: public int Compare(int? x, int? y) 4: { 5: return (x == null) 6: ? ((y == null) ? 0 : -1) 7: : x.Value.CompareTo(y); 8: } 9: }  Now, if you want a custom sort -- especially on large-grained objects with different possible sort fields -- this is the best option you have.  But if you just want to take advantage of the natural ordering of the type, there is an easier way.  If the type you want to compare already implements IComparable<T> or if the type is System.Nullable<T> where T implements IComparable, there is a class in the System.Collections.Generic namespace called Comparer<T> which exposes a property called Default that will create a singleton that represents the default comparer for items of that type.  For example: 1: // compares integers 2: var intComparer = Comparer<int>.Default; 3:  4: // compares DateTime values 5: var dateTimeComparer = Comparer<DateTime>.Default; 6:  7: // compares nullable doubles using the null rules! 8: var nullableDoubleComparer = Comparer<double?>.Default;  This helps you avoid having to remember the messy null logic and makes it to compare objects where you don’t know if one or more of the values is null. This works especially well when creating say an IComparer<T> implementation for a large-grained class that may or may not contain a field.  For example, let’s say you want to create a sorting comparer for a stock open price, but if the market the stock is trading in hasn’t opened yet, the open price will be null.  We could handle this (assuming a reasonable Quote definition) like: 1: public class Quote 2: { 3: // the opening price of the symbol quoted 4: public double? Open { get; set; } 5:  6: // ticker symbol 7: public string Symbol { get; set; } 8:  9: // etc. 10: } 11:  12: public class OpenPriceQuoteComparer : IComparer<Quote> 13: { 14: // Compares two quotes by opening price 15: public int Compare(Quote x, Quote y) 16: { 17: return Comparer<double?>.Default.Compare(x.Open, y.Open); 18: } 19: } Summary Defining a custom comparer is often needed for non-natural ordering or defining alternative orderings, but when you just want to compare two items that are IComparable<T> and account for null behavior, you can use the Comparer<T>.Default comparer generator and you’ll never have to worry about correct null value sorting again.     Technorati Tags: C#,.NET,Little Wonders,BlackRabbitCoder,IComparable,Comparer

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  • Refactoring Part 1 : Intuitive Investments

    - by Wes McClure
    Fear, it’s what turns maintaining applications into a nightmare.  Technology moves on, teams move on, someone is left to operate the application, what was green is now perceived brown.  Eventually the business will evolve and changes will need to be made.  The approach to those changes often dictates the long term viability of the application.  Fear of change, lack of passion and a lack of interest in understanding the domain often leads to a paranoia to do anything that doesn’t involve duct tape and bailing twine.  Don’t get me wrong, those have a place in the short term viability of a project but they don’t have a place in the long term.  Add to it “us versus them” in regards to the original team and those that maintain it, internal politics and other factors and you have a recipe for disaster.  This results in code that quickly becomes unmanageable.  Even the most clever of designs will eventually become sub optimal and debt will amount that exponentially makes changes difficult.  This is where refactoring comes in, and it’s something I’m very passionate about.  Refactoring is about improving the process whereby we make change, it’s an exponential investment in the process of change. Without it we will incur exponential complexity that halts productivity. Investments, especially in the long term, require intuition and reflection.  How can we tackle new development effectively via evolving the original design and paying off debt that has been incurred? The longer we wait to ask and answer this question, the more it will cost us.  Small requests don’t warrant big changes, but realizing when changes now will pay off in the long term, and especially in the short term, is valuable. I have done my fair share of maintaining applications and continuously refactoring as needed, but recently I’ve begun work on a project that hasn’t had much debt, if any, paid down in years.  This is the first in a series of blog posts to try to capture the process which is largely driven by intuition of smaller refactorings from other projects. Signs that refactoring could help: Testability How can decreasing test time not pay dividends? One of the first things I found was that a very important piece often takes 30+ minutes to test.  I can only imagine how much time this has cost historically, but more importantly the time it might cost in the coming weeks: I estimate at least 10-20 hours per person!  This is simply unacceptable for almost any situation.  As it turns out, about 6 hours of working with this part of the application and I was able to cut the time down to under 30 seconds!  In less than the lost time of one week, I was able to fix the problem for all future weeks! If we can’t test fast then we can’t change fast, nor with confidence. Code is used by end users and it’s also used by developers, consider your own needs in terms of the code base.  Adding logic to enable/disable features during testing can help decouple parts of an application and lead to massive improvements.  What exactly is so wrong about test code in real code?  Often, these become features for operators and sometimes end users.  If you cannot run an integration test within a test runner in your IDE, it’s time to refactor. Readability Are variables named meaningfully via a ubiquitous language? Is the code segmented functionally or behaviorally so as to minimize the complexity of any one area? Are aspects properly segmented to avoid confusion (security, logging, transactions, translations, dependency management etc) Is the code declarative (what) or imperative (how)?  What matters, not how.  LINQ is a great abstraction of the what, not how, of collection manipulation.  The Reactive framework is a great example of the what, not how, of managing streams of data. Are constants abstracted and named, or are they just inline? Do people constantly bitch about the code/design? If the code is hard to understand, it will be hard to change with confidence.  It’s a large undertaking if the original designers didn’t pay much attention to readability and as such will never be done to “completion.”  Make sure not to go over board, instead use this as you change an application, not in lieu of changes (like with testability). Complexity Simplicity will never be achieved, it’s highly subjective.  That said, a lot of code can be significantly simplified, tidy it up as you go.  Refactoring will often converge upon a simplification step after enough time, keep an eye out for this. Understandability In the process of changing code, one often gains a better understanding of it.  Refactoring code is a good way to learn how it works.  However, it’s usually best in combination with other reasons, in effect killing two birds with one stone.  Often this is done when readability is poor, in which case understandability is usually poor as well.  In the large undertaking we are making with this legacy application, we will be replacing it.  Therefore, understanding all of its features is important and this refactoring technique will come in very handy. Unused code How can deleting things not help? This is a freebie in refactoring, it’s very easy to detect with modern tools, especially in statically typed languages.  We have VCS for a reason, if in doubt, delete it out (ok that was cheesy)! If you don’t know where to start when refactoring, this is an excellent starting point! Duplication Do not pray and sacrifice to the anti-duplication gods, there are excellent examples where consolidated code is a horrible idea, usually with divergent domains.  That said, mediocre developers live by copy/paste.  Other times features converge and aren’t combined.  Tools for finding similar code are great in the example of copy/paste problems.  Knowledge of the domain helps identify convergent concepts that often lead to convergent solutions and will give intuition for where to look for conceptual repetition. 80/20 and the Boy Scouts It’s often said that 80% of the time 20% of the application is used most.  These tend to be the parts that are changed.  There are also parts of the code where 80% of the time is spent changing 20% (probably for all the refactoring smells above).  I focus on these areas any time I make a change and follow the philosophy of the Boy Scout in cleaning up more than I messed up.  If I spend 2 hours changing an application, in the 20%, I’ll always spend at least 15 minutes cleaning it or nearby areas. This gives a huge productivity edge on developers that don’t. Ironically after a short period of time the 20% shrinks enough that we don’t have to spend 80% of our time there and can move on to other areas.   Refactoring is highly subjective, never attempt to refactor to completion!  Learn to be comfortable with leaving one part of the application in a better state than others.  It’s an evolution, not a revolution.  These are some simple areas to look into when making changes and can help get one started in the process.  I’ve often found that refactoring is a convergent process towards simplicity that sometimes spans a few hours but often can lead to massive simplifications over the timespan of weeks and months of regular development.

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  • Partner Blog Series: PwC Perspectives Part 2 - Jumpstarting your IAM program with R2

    - by Tanu Sood
    Identity and access management (IAM) isn’t a new concept. Over the past decade, companies have begun to address identity management through a variety of solutions that have primarily focused on provisioning. . The new age workforce is converging at a rapid pace with ever increasing demand to use diverse portfolio of applications and systems to interact and interface with their peers in the industry and customers alike. Oracle has taken a significant leap with their release of Identity and Access Management 11gR2 towards enabling this global workforce to conduct their business in a secure, efficient and effective manner. As companies deal with IAM business drivers, it becomes immediately apparent that holistic, rather than piecemeal, approaches better address their needs. When planning an enterprise-wide IAM solution, the first step is to create a common framework that serves as the foundation on which to build the cost, compliance and business process efficiencies. As a leading industry practice, IAM should be established on a foundation of accurate data for identity management, making this data available in a uniform manner to downstream applications and processes. Mature organizations are looking beyond IAM’s basic benefits to harness more advanced capabilities in user lifecycle management. For any organization looking to embark on an IAM initiative, consider the following use cases in managing and administering user access. Expanding the Enterprise Provisioning Footprint Almost all organizations have some helpdesk resources tied up in handling access requests from users, a distraction from their core job of handling problem tickets. This dependency has mushroomed from the traditional acceptance of provisioning solutions integrating and addressing only a portion of applications in the heterogeneous landscape Oracle Identity Manager (OIM) 11gR2 solves this problem by offering integration with third party ticketing systems as “disconnected applications”. It allows for the existing business processes to be seamlessly integrated into the system and tracked throughout its lifecycle. With minimal effort and analysis, an organization can begin integrating OIM with groups or applications that are involved with manually intensive access provisioning and de-provisioning activities. This aspect of OIM allows organizations to on-board applications and associated business processes quickly using out of box templates and frameworks. This is especially important for organizations looking to fold in users and resources from mergers and acquisitions. Simplifying Access Requests Organizations looking to implement access request solutions often find it challenging to get their users to accept and adopt the new processes.. So, how do we improve the user experience, make it intuitive and personalized and yet simplify the user access process? With R2, OIM helps organizations alleviate the challenge by placing the most used functionality front and centre in the new user request interface. Roles, application accounts, and entitlements can all be found in the same interface as catalog items, giving business users a single location to go to whenever they need to initiate, approve or track a request. Furthermore, if a particular item is not relevant to a user’s job function or area inside the organization, it can be hidden so as to not overwhelm or confuse the user with superfluous options. The ability to customize the user interface to suit your needs helps in exercising the business rules effectively and avoiding access proliferation within the organization. Saving Time with Templates A typical use case that is most beneficial to business users is flexibility to place, edit, and withdraw requests based on changing circumstances and business needs. With OIM R2, multiple catalog items can now be added and removed from the shopping cart, an ecommerce paradigm that many users are already familiar with. This feature can be especially useful when setting up a large number of new employees or granting existing department or group access to a newly integrated application. Additionally, users can create their own shopping cart templates in order to complete subsequent requests more quickly. This feature saves the user from having to search for and select items all over again if a request is similar to a previous one. Advanced Delegated Administration A key feature of any provisioning solution should be to empower each business unit in managing their own access requests. By bringing administration closer to the user, you improve user productivity, enable efficiency and alleviate the administration overhead. To do so requires a federated services model so that the business units capable of shouldering the onus of user life cycle management of their business users can be enabled to do so. OIM 11gR2 offers advanced administrative options for creating, managing and controlling business logic and workflows through easy to use administrative interface and tools that can be exposed to delegated business administrators. For example, these business administrators can establish or modify how certain requests and operations should be handled within their business unit based on a number of attributes ranging from the type of request or the risk level of the individual items requested. Closed-Loop Remediation Security continues to be a major concern for most organizations. Identity management solutions bolster security by ensuring only the right users have the right access to the right resources. To prevent unauthorized access and where it already exists, the ability to detect and remediate it, are key requirements of an enterprise-grade proven solution. But the challenge with most solutions today is that some of this information still exists in silos. And when changes are made to systems directly, not all information is captured. With R2, oracle is offering a comprehensive Identity Governance solution that our customer organizations are leveraging for closed loop remediation that allows for an automated way for administrators to revoke unauthorized access. The change is automatically captured and the action noted for continued management. Conclusion While implementing provisioning solutions, it is important to keep the near term and the long term goals in mind. The provisioning solution should always be a part of a larger security and identity management program but with the ability to seamlessly integrate not only with the company’s infrastructure but also have the ability to leverage the information, business models compiled and used by the other identity management solutions. This allows organizations to reduce the cost of ownership, close security gaps and leverage the existing infrastructure. And having done so a multiple clients’ sites, this is the approach we recommend. In our next post, we will take a journey through our experiences of advising clients looking to upgrade to R2 from a previous version or migrating from a different solution. Meet the Writers:   Praveen Krishna is a Manager in the Advisory Security practice within PwC.  Over the last decade Praveen has helped clients plan, architect and implement Oracle identity solutions across diverse industries.  His experience includes delivering security across diverse topics like network, infrastructure, application and data where he brings a holistic point of view to problem solving. Dharma Padala is a Director in the Advisory Security practice within PwC.  He has been implementing medium to large scale Identity Management solutions across multiple industries including utility, health care, entertainment, retail and financial sectors.   Dharma has 14 years of experience in delivering IT solutions out of which he has been implementing Identity Management solutions for the past 8 years. Scott MacDonald is a Director in the Advisory Security practice within PwC.  He has consulted for several clients across multiple industries including financial services, health care, automotive and retail.   Scott has 10 years of experience in delivering Identity Management solutions. John Misczak is a member of the Advisory Security practice within PwC.  He has experience implementing multiple Identity and Access Management solutions, specializing in Oracle Identity Manager and Business Process Engineering Language (BPEL). Jenny (Xiao) Zhang is a member of the Advisory Security practice within PwC.  She has consulted across multiple industries including financial services, entertainment and retail. Jenny has three years of experience in delivering IT solutions out of which she has been implementing Identity Management solutions for the past one and a half years.

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  • Developing Schema Compare for Oracle (Part 1)

    - by Simon Cooper
    SQL Compare is one of Red Gate's most successful SQL Server tools; it allows developers and DBAs to compare and synchronize the contents of their databases. Although similar tools exist for Oracle, they are quite noticeably lacking in the usability and stability that SQL Compare is known for in the SQL Server world. We could see a real need for a usable schema comparison tools for Oracle, and so the Schema Compare for Oracle project was born. Over the next few weeks, as we come up to release of v1, I'll be doing a series of posts on the development of Schema Compare for Oracle. For the first post, I thought I would start with the main pitfalls that we stumbled across when developing the product, especially from a SQL Server background. 1. Schemas and Databases The most obvious difference is that the concept of a 'database' is quite different between Oracle and SQL Server. On SQL Server, one server instance has multiple databases, each with separate schemas. There is typically little communication between separate databases, and most databases are no more than about 1000-2000 objects. This means SQL Compare can register an entire database in a reasonable amount of time, and cross-database dependencies probably won't be an issue. It is a quite different scene under Oracle, however. The terms 'database' and 'instance' are used interchangeably, (although technically 'database' refers to the datafiles on disk, and 'instance' the running Oracle process that reads & writes to the database), and a database is a single conceptual entity. This immediately presents problems, as it is infeasible to register an entire database as we do in SQL Compare; in my Oracle install, using the standard recommended options, there are 63975 system objects. If we tried to register all those, not only would it take hours, but the client would probably run out of memory before we finished. As a result, we had to allow people to specify what schemas they wanted to register. This decision had quite a few knock-on effects for the design, which I will cover in a future post. 2. Connecting to Oracle The next obvious difference is in actually connecting to Oracle – in SQL Server, you can specify a server and database, and off you go. On Oracle things are slightly more complicated. SIDs, Service Names, and TNS A database (the files on disk) must have a unique identifier for the databases on the system, called the SID. It also has a global database name, which consists of a name (which doesn't have to match the SID) and a domain. Alternatively, you can identify a database using a service name, which normally has a 1-to-1 relationship with instances, but may not if, for example, using RAC (Real Application Clusters) for redundancy and failover. You specify the computer and instance you want to connect to using TNS (Transparent Network Substrate). The user-visible parts are a config file (tnsnames.ora) on the client machine that specifies how to connect to an instance. For example, the entry for one of my test instances is: SC_11GDB1 = (DESCRIPTION = (ADDRESS_LIST = (ADDRESS = (PROTOCOL = TCP)(HOST = simonctest)(PORT = 1521)) ) (CONNECT_DATA = (SID = 11gR1db1) ) ) This gives the hostname, port, and SID of the instance I want to connect to, and associates it with a name (SC_11GDB1). The tnsnames syntax also allows you to specify failover, multiple descriptions and address lists, and client load balancing. You can then specify this TNS identifier as the data source in a connection string. Although using ODP.NET (the .NET dlls provided by Oracle) was fine for internal prototype builds, once we released the EAP we discovered that this simply wasn't an acceptable solution for installs on other people's machines. Due to .NET assembly strong naming, users had to have installed on their machines the exact same version of the ODP.NET dlls as we had on our build server. We couldn't ship the ODP.NET dlls with our installer as the Oracle license agreement prohibited this, and we didn't want to force users to install another Oracle client just so they can run our program. To be able to list the TNS entries in the connection dialog, we also had to locate and parse the tnsnames.ora file, which was complicated by users with several Oracle client installs and intricate TNS entries. After much swearing at our computers, we eventually decided to use a third party Oracle connection library from Devart that we could ship with our program; this could use whatever client version was installed, parse the TNS entries for us, and also had the nice feature of being able to connect to an Oracle server without having any client installed at all. Unfortunately, their current license agreement prevents us from shipping an Oracle SDK, but that's a bridge we'll cross when we get to it. 3. Running synchronization scripts The most important difference is that in Oracle, DDL is non-transactional; you cannot rollback DDL statements like you can on SQL Server. Although we considered various solutions to this, including using the flashback archive or recycle bin, or generating an undo script, no reliable method of completely undoing a half-executed sync script has yet been found; so in this case we simply have to trust that the DBA or developer will check and verify the script before running it. However, before we got to that stage, we had to get the scripts to run in the first place... To run a synchronization script from SQL Compare we essentially pass the script over to the SqlCommand.ExecuteNonQuery method. However, when we tried to do the same for an OracleConnection we got a very strange error – 'ORA-00911: invalid character', even when running the most basic CREATE TABLE command. After much hair-pulling and Googling, we discovered that Oracle has got some very strange behaviour with semicolons at the end of statements. To understand what's going on, we need to take a quick foray into SQL and PL/SQL. PL/SQL is not T-SQL In SQL Server, T-SQL is the language used to interface with the database. It has DDL, DML, control flow, and many other nice features (like Turing-completeness) that you can mix and match in the same script. In Oracle, DDL SQL and PL/SQL are two completely separate languages, with different syntax, different datatypes and different execution engines within the instance. Oracle SQL is much more like 'pure' ANSI SQL, with no state, no control flow, and only the basic DML commands. PL/SQL is the Turing-complete language, but can only do DML and DCL (i.e. BEGIN TRANSATION commands). Any DDL or SQL commands that aren't recognised by the PL/SQL engine have to be passed back to the SQL engine via an EXECUTE IMMEDIATE command. In PL/SQL, a semicolons is a valid token used to delimit the end of a statement. In SQL, a semicolon is not a valid token (even though the Oracle documentation gives them at the end of the syntax diagrams) . When you execute the command CREATE TABLE table1 (COL1 NUMBER); in SQL*Plus the semicolon on the end is a command to SQL*Plus to execute the preceding statement on the server; it strips off the semicolon before passing it on. SQL Developer does a similar thing. When executing a PL/SQL block, however, the syntax is like so: BEGIN INSERT INTO table1 VALUES (1); INSERT INTO table1 VALUES (2); END; / In this case, the semicolon is accepted by the PL/SQL engine as a statement delimiter, and instead the / is the command to SQL*Plus to execute the current block. This explains the ORA-00911 error we got when trying to run the CREATE TABLE command – the server is complaining about the semicolon on the end. This also means that there is no SQL syntax to execute more than one DDL command in the same OracleCommand. Therefore, we would have to do a round-trip to the server for every command we want to execute. Obviously, this would cause lots of network traffic and be very slow on slow or congested networks. Our first attempt at a solution was to wrap every SQL statement (without semicolon) inside an EXECUTE IMMEDIATE command in a PL/SQL block and pass that to the server to execute. One downside of this solution is that we get no feedback as to how the script execution is going; we're currently evaluating better solutions to this thorny issue. Next up: Dependencies; how we solved the problem of being unable to register the entire database, and the knock-on effects to the whole product.

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  • Orchestrating the Virtual Enterprise

    - by John Murphy
    During the American Industrial Revolution, the Ford Motor Company did it all. It turned raw materials into a showroom full of Model Ts. It owned a steel mill, a glass factory, and an automobile assembly line. The company was both self-sufficient and innovative and went on to become one of the largest and most profitable companies in the world. Nowadays, it's unusual for any business to follow this vertical integration model because its much harder to be best in class across such a wide a range of capabilities and services. Instead, businesses focus on their core competencies and outsource other business functions to specialized suppliers. They exchange vertical integration for collaboration. When done well, all parties benefit from this arrangement and the collaboration leads to the creation of an agile, lean and successful "virtual enterprise." Case in point: For Sun hardware, Oracle outsources most of its manufacturing and all of its logistics to third parties. These are vital activities, but ones where Oracle doesn't have a core competency, so we shift them to business partners who do. Within our enterprise, we always retain the core functions of product development, support, and most of the sales function, because that's what constitutes our core value to our customers. This is a perfect example of a virtual enterprise.  What are the implications of this? It means that we must exchange direct internal control for indirect external collaboration. This fundamentally changes the relative importance of different business processes, the boundaries of security and information sharing, and the relationship of the supply chain systems to the ERP. The challenge is that the systems required to support this virtual paradigm are still mired in "island enterprise" thinking. But help is at hand. Developments such as the Web, social networks, collaboration, and rules-based orchestration offer great potential to fundamentally re-architect supply chain systems to better support the virtual enterprise.  Supply Chain Management Systems in a Virtual Enterprise Historically enterprise software was constructed to automate the ERP - and then the supply chain systems extended the ERP. They were joined at the hip. In virtual enterprises, the supply chain system needs to be ERP agnostic, sitting above each of the ERPs that are distributed across the virtual enterprise - most of which are operating in other businesses. This is vital so that the supply chain system can manage the flow of material and the related information through the multiple enterprises. It has to have strong collaboration tools. It needs to be highly flexible. Users need to be able to see information that's coming from multiple sources and be able to react and respond to events across those sources.  Oracle Fusion Distributed Order Orchestration (DOO) is a perfect example of a supply chain system designed to operate in this virtual way. DOO embraces the idea that a company's fulfillment challenge is a distributed, multi-enterprise problem. It enables users to manage the process and the trading partners in a uniform way and deliver a consistent user experience while operating over a heterogeneous, virtual enterprise. This is a fundamental shift at the core of managing supply chains. It forces virtual enterprises to think architecturally about how best to construct their supply chain systems.  Case in point, almost everyone has ordered from Amazon.com at one time or another. Our orders are as likely to be fulfilled by third parties as they are by Amazon itself. To deliver the order promptly and efficiently, Amazon has to send it to the right fulfillment location and know the availability in that location. It needs to be able to track status of the fulfillment and deal with exceptions. As a virtual enterprise, Amazon's operations, using thousands of trading partners, requires a very different approach to fulfillment than the traditional 'take an order and ship it from your own warehouse' model. Amazon had no choice but to develop a complex, expensive and custom solution to tackle this problem as there used to be no product solution available. Now, other companies who want to follow similar models have a better off-the-shelf choice -- Oracle Distributed Order Orchestration (DOO).  Consider how another of our customers is using our distributed orchestration solution. This major airplane manufacturer has a highly complex business and interacts regularly with the U.S. Government and major airlines. It sits in the middle of an intricate supply chain and needed to improve visibility across its many different entities. Oracle Fusion DOO gives the company an orchestration mechanism so it could improve quality, speed, flexibility, and consistency without requiring an organ transplant of these highly complex legacy systems. Many retailers face the challenge of dealing with brick and mortar, Web, and reseller channels. They all need to be knitted together into a virtual enterprise experience that is consistent for their customers. When a large U.K. grocer with a strong brick and mortar retail operation added an online business, they turned to Oracle Fusion DOO to bring these entities together. Disturbing the Peace with Acquisitions Quite often a company's ERP system is disrupted when it acquires a new company. An acquisition can inject a new set of processes and systems -- or even introduce an entirely new business like Sun's hardware did at Oracle. This challenge has been a driver for some of our DOO customers. A large power management company is using Oracle Fusion DOO to provide the flexibility to rapidly integrate additional products and services into its central fulfillment operation. The Flip Side of Fulfillment Meanwhile, we haven't ignored similar challenges on the supply side of the equation. Specifically, how to manage complex supply in a flexible way when there are multiple trading parties involved? How to manage the supply to suppliers? How to manage critical components that need to merge in a tier two or tier three supply chain? By investing in supply orchestration solutions for the virtual enterprise, we plan to give users better visibility into their network of suppliers to help them drive down costs. We also think this technology and full orchestration process can be applied to the financial side of organizations. An example is transactions that flow through complex internal structures to minimize tax exposure. We can help companies manage those transactions effectively by thinking about the internal organization as a virtual enterprise and bringing the same solution set to this internal challenge.  The Clear Front Runner No other company is investing in solving the virtual enterprise supply chain issues like Oracle is. Oracle is in a unique position to become the gold standard in this market space. We have the infrastructure of Oracle technology. We already have an Oracle Fusion DOO application which embraces the best of what's required in this area. And we're absolutely committed to extending our Fusion solution to other use cases and delivering even more business value.

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  • Behavior Driven Development (BDD) and DevExpress XAF

    - by Patrick Liekhus
    So in my previous posts I showed you how I used EDMX to quickly build my business objects within XPO and XAF.  But how do you test whether your business objects are actually doing what you want and verify that your business logic is correct?  Well I was reading my monthly MSDN magazine last last year and came across an article about using SpecFlow and WatiN to build BDD tests.  So why not use these same techniques to write SpecFlow style scripts and have them generate EasyTest scripts for use with XAF.  Let me outline and show a few things below.  I plan on releasing this code in a short while, I just wanted to preview what I was thinking. Before we begin… First, if you have not read the article in MSDN, here is the link to the article that I found my inspiration.  It covers the overview of BDD vs. TDD, how to write some of the SpecFlow syntax and how use the “Steps” logic to create your own tests. Second, if you have not heard of EasyTest from DevExpress I strongly recommend you review it here.  It basically takes the power of XAF and the beauty of your application and allows you to create text based files to execute automated commands within your application. Why would we do this?  Because as you will see below, the cucumber syntax is easier for business analysts to interpret and digest the business rules from.  You can find most of the information you will need on Cucumber syntax within The Secret Ninja Cucumber Scrolls located here.  The basics of the syntax are that Given X When Y Then Z.  For example, Given I am at the login screen When I enter my login credentials Then I expect to see the home screen.  Pretty easy syntax to follow. Finally, we will need to download and install SpecFlow.  You can find it on their website here.  Once you have this installed then let’s write our first test. Let’s get started… So where to start.  Create a new testing project within your solution.  I typically call this with a similar naming convention as used by XAF, my project name .FunctionalTests (i.e.  AlbumManager.FunctionalTests).  Remove the basic test that is created for you.  We will not use the default test but rather create our own SpecFlow “Feature” files.  Add a new item to your project and select the SpecFlow Feature file under C#.  Name your feature file as you do your class files after the test they are performing. Now you can crack open your new feature file and write the actual test.  Make sure to have your Ninja Scrolls from above as it provides valuable resources on how to write your test syntax.  In this test below you can see how I defined the documentation in the Feature section.  This is strictly for our purposes of readability and do not effect the test.  The next section is the Scenario Outline which is considered a test template.  You can see the brackets <> around the fields that will be filled in for each test.  So in the example below you can see that Given I am starting a new test and the application is open.  This means I want a new EasyTest file and the windows application generated by XAF is open.  Next When I am at the Albums screen tells XAF to navigate to the Albums list view.  And I click the New:Album button, tells XAF to click the new button on the list grid.  And I enter the following information tells XAF which fields to complete with the mapped values.  And I click the Save and Close button causes the record to be saved and the detail form to be closed.  Then I verify results tests the input data against what is visible in the grid to ensure that your record was created. The Scenarios section gives each test a unique name and then fills in the values for each test.  This way you can use the same test to make multiple passes with different data. Almost there.  Now we must save the feature file and the BDD tests will be written using standard unit test syntax.  This is all handled for you by SpecFlow so just save the file.  What you will see in your Test List Editor is a unit test for each of the above scenarios you just built. You can now use standard unit testing frameworks to execute the test as you desire.  As you would expect then, these BDD SpecFlow tests can be automated into your build process to ensure that your business requirements are satisfied each and every time. How does it work? What we have done is to intercept the testing logic at runtime to interpret the SpecFlow syntax into EasyTest syntax.  This is the basic StepDefinitions that we are working on now.  We expect to put these on CodePlex within the next few days.  You can always override and make your own rules as you see fit for your project.  Follow the MSDN magazine above to start your own.  You can see part of our implementation below. As you can gather from the MSDN article and the code sample below, we have created our own common rules to build the above syntax. The code implementation for these rules basically saves your information from the feature file into an EasyTest file format.  It then executes the EasyTest file and parses the XML results of the test.  If the test succeeds the test is passed.  If the test fails, the EasyTest failure message is logged and the screen shot (as captured by EasyTest) is saved for your review. Again we are working on getting this code ready for mass consumption, but at this time it is not ready.  We will post another message when it is ready with all details about usage and setup. Thanks

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  • Translating Your Customizations

    - by Richard Bingham
    This blog post explains the basics of translating the customizations you can make to Fusion Applications products, with the inclusion of information for both composer-based customizations and the generic design-time customizations done via JDeveloper. Introduction Like most Oracle Applications, Fusion Applications installs on-premise with a US-English base language that is, in Release 7, supported by the option to add up to a total of 22 additional language packs (In Oracle Cloud production environments languages are pre-installed already). As such many organizations offer their users the option of working with their local language, and logically that should also apply for any customizations as well. Composer-based UI Customizations Customizations made in Page Composer take into consideration the session LOCALE, as set in the user preferences screen, during all customization work, and stores the customization in the MDS repository accordingly. As such the actual new or changed values used will only apply for the same language under which the customization was made, and text for any other languages requires a separate upload. See the Resource Bundles section below, which incidentally also applies to custom UI changes done in JDeveloper. You may have noticed this when you select the “Select Text Resource” menu option when editing the text on a page. Using this ensures that the resource bundles are used, whereas if you define a static value in Expression Builder it will never be available for translation. Notice in the screenshot below the “What’s New” custom value I have already defined using the ‘Select Text Resource’ feature is internally using the adfBundle groovy function to pull the custom value for my key (RT_S_1) from the ComposerOverrideBundle. Figure 1 – Page Composer showing the override bundle being used. Business Objects Customizing the Business Objects available in the Applications Composer tool for the CRM products, such as adding additional fields, also operates using the session language. Translating these additional values for these fields into other installed languages requires loading additional resource bundles, again as described below. Reports and Analytics Most customizations to Reports and BI Analytics are just essentially reorganizations and visualizations of existing number and text data from the system, and as such will use the appropriate values based on the users session language. Where a translated value or string exists for that session language, it will be used without the need for additional work. Extending through the addition of brand new reports and analytics requires another method of loading the translated strings, as part of what is known as ‘Localizing’ the BI Catalog and Metadata. This time it is via an export/import of XML data through the BI Administrators console, and is described in the OBIEE Admin Guide. Fusion Applications reports based on BI Publisher are already defined in template-per-locale, and in addition provide an extra process for getting the data for translation and reloading. This again uses the standard resource bundle format. Loading a custom report is illustrated in this video from our YouTube channel which shows the screen for both setting the template local and running an export for translation. Fusion Applications Menus Whilst the seeded Navigator and Global Menu values are fully translated when the additional language is installed, if they are customized then the change or new menu item will apply universally, not currently per language. This is set to change in a future release with the new UI Text Editor feature described below. More on Resource Bundles As mentioned above, to provide translations for most of your customizations you need to add values to a resource bundle. This is an industry open standard (OASIS) format XML file with the extension .xliff, and store translated values for the strings used by ADF at run-time. The general process is that these values are exported from the MDS repository, manually edited, and then imported back in again.This needs to be done by an administrator, via either WLST commands or through Enterprise Manager as per the screenshot below. This is detailed out in the Fusion Applications Extensibility Guide. For SaaS environments the Cloud Operations team can assist. Figure 2 – Enterprise Manager’s MDS export used getting resource bundles for manual translation and re-imported on the same screen. All customized strings are stored in an override bundle (xliff file) for each locale, suffixed with the language initials, with English ones being saved to the default. As such each language bundle can be easily identified and updated. Similarly if you used JDeveloper to create your own applications as extensions to Fusion Applications you would use the native support for resource bundles, and add them into the faces-config.xml file for inclusion in your application. An example is this ADF customization video from our YouTube channel. JDeveloper also supports automatic synchronization between your underlying resource bundles and any translatable strings you add – very handy. For more information see chapters on “Using Automatic Resource Bundle Integration in JDeveloper” and “Manually Defining Resource Bundles and Locales” in the Oracle Fusion Middleware Web User Interface Developer’s Guide for Oracle Application Development Framework. FND Messages and Look-ups FND Messages, as defined here, are not used for UI labels (they are known as ‘strings’), but are the responses back to users as a result of an action, such as from a page submit. Each ‘message’ is defined and stored in the related database table (FND_MESSAGES_B), with another (FND_MESSAGES_TL) holding any language-specific values. These come seeded with the additional language installs, however if you customize the messages via the “Manage Messages” task in Functional Setup Manager, or add new ones, then currently (in Release 7) you’ll need to repeat it for each language. Figure 3 – An FND Message defined in an English user session. Similarly Look-ups are stored in a translation table (FND_LOOKUP_VALUES_TL) where appropriate, and can be customized by setting the users session language and making the change  in the Setup and Maintenance task entitled “Manage [Standard|Common] Look-ups”. Online Help Yes, in fact all the seeded help is applied as part of each language pack install as part of the post-install provisioning process. If you are editing or adding custom online help then the Create Help screen provides a drop-down of which language your help customization will apply to. This is shown in the video below from our YouTube channel, and obviously you’ll need to it for each language in use. What is Coming for Translations? Currently planned for Release 8 is something called the User Interface (UI) Text Editor. This tool will allow the editing of all the text shown on the pages and forms of Fusion Application. This will provide a search based on a particular term or word, say “Worker”, and will allow it to be adjusted, say to “Employee”, which then updates all the Resource Bundles that contain it. In the case of multi-language environments, it will use the users session language (locale) to know which Resource Bundles to apply the change to. This capability will also support customization sandboxes, to help ensure changes can be tested and approved.  It is also interesting to note that the design currently allows any page-specific customizations done using Page Composer or Application Composer to over-write the global changes done via the UI Text Editor, allowing for special context-sensitive values to still be used. Further Reading and Resources The following short list provides the mains resources for digging into more detail on translation support for both Composer and JDeveloper customization projects. There is a dedicated chapter entitled “Translating Custom Text” in the Fusion Applications Extensibility Guide. This has good examples and steps for many tasks, especially administering resource bundles. Using localization formatting (numbers, dates etc) for design-time changes is well documented in the Fusion Applications Developer Guide. For more guidelines on general design-time globalization, see either the ‘Internationalizing and Localizing Pages’ chapter in the Oracle Fusion Middleware Web User Interface Developer’s Guide for Oracle Application Development Framework (Oracle Fusion Applications Edition) or the general Oracle Database Globalization Support Guide. The Oracle Architecture ‘A-Team’ provided a recent post on customizing the user session timeout popup, using design-time changes to resource bundles. It has detailed step-by-step examples which can be a useful illustration.

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  • Partner Blog Series: PwC Perspectives - Looking at R2 for Customer Organizations

    - by Tanu Sood
    Welcome to the first of our partner blog series. November Mondays are all about PricewaterhouseCoopers' perespective on Identity and R2. In this series, we have identity management experts from PricewaterhouseCoopers (PwC) share their perspective on (and experiences with) the recent identity management release, Oracle Identity Management R2. The purpose of the series is to discuss real world identity use cases that helped shape the innovations in the recent R2 release and the implementation strategies that customers are employing today with expertise from PwC. Part 1: Looking at R2 for Customer Organizations In this inaugural post, we will discuss some of the new features of the R2 release of Oracle Identity Manager that some of our customer organizations are implementing today and the business rationale for those. Oracle's R2 Security portfolio represents a solid step forward for a platform that is already market-leading.  Prior to R2, Oracle was an industry titan in security with reliable products, expansive compatibility, and a large customer base.  Oracle has taken their identity platform to the next level in their latest version, R2.  The new features include a customizable UI, a request catalog, flexible security, and enhancements for its connectors, and more. Oracle customers will be impressed by the new Oracle Identity Manager (OIM) business-friendly UI.  Without question, Oracle has invested significant time in responding to customer feedback about making access requests and related activities easier for non-IT users.  The flexibility to add information to screens, hide fields that are not important to a particular customer, and adjust web themes to suit a company's preference make Oracle's Identity Manager stand out among its peers.  Customers can also expect to carry UI configurations forward with minimal migration effort to future versions of OIM.  Oracle's flexible UI will benefit many organizations looking for a customized feel with out-of-the-box configurations. Organizations looking to extend their services to end users will benefit significantly from new usability features like OIM’s ‘Catalog.’  Customers familiar with Oracle Identity Analytics' 'Glossary' feature will be able to relate to the concept.  It will enable Roles, Entitlements, Accounts, and Resources to be requested through the out-of-the-box UI.  This is an industry-changing feature as customers can make the process to request access easier than ever.  For additional ease of use, Oracle has introduced a shopping cart style request interface that further simplifies the experience for end users.  Common requests can be setup as profiles to save time.  All of this is combined with the approval workflow engine introduced in R1 that provides the flexibility customers need to meet their compliance requirements. Enhanced security was also on the list of features Oracle wanted to deliver to its customers.  The new end-user UI provides additional granular access controls.  Common Help Desk use cases can be implemented with ease by updating the application profiles.  Access can be rolled out so that administrators can only manage a certain department or organization.  Further, OIM can be more easily configured to select which fields can be read-only vs. updated.  Finally, this security model can be used to limit search results for roles and entitlements intended for a particular department.  Every customer has a different need for access and OIM now matches this need with a flexible security model. One of the important considerations when selecting an Identity Management platform is compatibility.  The number of supported platform connectors and how well it can integrate with non-supported platforms is a key consideration for selecting an identity suite.  Oracle has a long list of supported connectors.  When a customer has a requirement for a platform not on that list, Oracle has a solution too.  Oracle is introducing a simplified architecture called Identity Connector Framework (ICF), which holds the potential to simplify custom connectors.  Finally, Oracle has introduced a simplified process to profile new disconnected applications from the web browser.  This is a useful feature that enables administrators to profile applications quickly as well as empowering the application owner to fulfill requests from their web browser.  Support will still be available for connectors based on previous versions in R2. Oracle Identity Manager's new R2 version has delivered many new features customers have been asking for.  Oracle has matured their platform with R2, making it a truly distinctive platform among its peers. In our next post, expect a deep dive into use cases for a customer considering R2 as their new Enterprise identity solution. In the meantime, we look forward to hearing from you about the specific challenges you are facing and your experience in solving those. Meet the Writers Dharma Padala is a Director in the Advisory Security practice within PwC.  He has been implementing medium to large scale Identity Management solutions across multiple industries including utility, health care, entertainment, retail and financial sectors.   Dharma has 14 years of experience in delivering IT solutions out of which he has been implementing Identity Management solutions for the past 8 years. Scott MacDonald is a Director in the Advisory Security practice within PwC.  He has consulted for several clients across multiple industries including financial services, health care, automotive and retail.   Scott has 10 years of experience in delivering Identity Management solutions. John Misczak is a member of the Advisory Security practice within PwC.  He has experience implementing multiple Identity and Access Management solutions, specializing in Oracle Identity Manager and Business Process Engineering Language (BPEL). Jenny (Xiao) Zhang is a member of the Advisory Security practice within PwC.  She has consulted across multiple industries including financial services, entertainment and retail. Jenny has three years of experience in delivering IT solutions out of which she has been implementing Identity Management solutions for the past one and a half years. Praveen Krishna is a Manager in the Advisory  Security practice within PwC.  Over the last decade Praveen has helped clients plan, architect and implement Oracle identity solutions across diverse industries.  His experience includes delivering security across diverse topics like network, infrastructure, application and data where he brings a holistic point of view to problem solving.

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  • Scheduling thread tiles with C++ AMP

    - by Daniel Moth
    This post assumes you are totally comfortable with, what some of us call, the simple model of C++ AMP, i.e. you could write your own matrix multiplication. We are now ready to explore the tiled model, which builds on top of the non-tiled one. Tiling the extent We know that when we pass a grid (which is just an extent under the covers) to the parallel_for_each call, it determines the number of threads to schedule and their index values (including dimensionality). For the single-, two-, and three- dimensional cases you can go a step further and subdivide the threads into what we call tiles of threads (others may call them thread groups). So here is a single-dimensional example: extent<1> e(20); // 20 units in a single dimension with indices from 0-19 grid<1> g(e);      // same as extent tiled_grid<4> tg = g.tile<4>(); …on the 3rd line we subdivided the single-dimensional space into 5 single-dimensional tiles each having 4 elements, and we captured that result in a concurrency::tiled_grid (a new class in amp.h). Let's move on swiftly to another example, in pictures, this time 2-dimensional: So we start on the left with a grid of a 2-dimensional extent which has 8*6=48 threads. We then have two different examples of tiling. In the first case, in the middle, we subdivide the 48 threads into tiles where each has 4*3=12 threads, hence we have 2*2=4 tiles. In the second example, on the right, we subdivide the original input into tiles where each has 2*2=4 threads, hence we have 4*3=12 tiles. Notice how you can play with the tile size and achieve different number of tiles. The numbers you pick must be such that the original total number of threads (in our example 48), remains the same, and every tile must have the same size. Of course, you still have no clue why you would do that, but stick with me. First, we should see how we can use this tiled_grid, since the parallel_for_each function that we know expects a grid. Tiled parallel_for_each and tiled_index It turns out that we have additional overloads of parallel_for_each that accept a tiled_grid instead of a grid. However, those overloads, also expect that the lambda you pass in accepts a concurrency::tiled_index (new in amp.h), not an index<N>. So how is a tiled_index different to an index? A tiled_index object, can have only 1 or 2 or 3 dimensions (matching exactly the tiled_grid), and consists of 4 index objects that are accessible via properties: global, local, tile_origin, and tile. The global index is the same as the index we know and love: the global thread ID. The local index is the local thread ID within the tile. The tile_origin index returns the global index of the thread that is at position 0,0 of this tile, and the tile index is the position of the tile in relation to the overall grid. Confused? Here is an example accompanied by a picture that hopefully clarifies things: array_view<int, 2> data(8, 6, p_my_data); parallel_for_each(data.grid.tile<2,2>(), [=] (tiled_index<2,2> t_idx) restrict(direct3d) { /* todo */ }); Given the code above and the picture on the right, what are the values of each of the 4 index objects that the t_idx variables exposes, when the lambda is executed by T (highlighted in the picture on the right)? If you can't work it out yourselves, the solution follows: t_idx.global       = index<2> (6,3) t_idx.local          = index<2> (0,1) t_idx.tile_origin = index<2> (6,2) t_idx.tile             = index<2> (3,1) Don't move on until you are comfortable with this… the picture really helps, so use it. Tiled Matrix Multiplication Example – part 1 Let's paste here the C++ AMP matrix multiplication example, bolding the lines we are going to change (can you guess what the changes will be?) 01: void MatrixMultiplyTiled_Part1(vector<float>& vC, const vector<float>& vA, const vector<float>& vB, int M, int N, int W) 02: { 03: 04: array_view<const float,2> a(M, W, vA); 05: array_view<const float,2> b(W, N, vB); 06: array_view<writeonly<float>,2> c(M, N, vC); 07: parallel_for_each(c.grid, 08: [=](index<2> idx) restrict(direct3d) { 09: 10: int row = idx[0]; int col = idx[1]; 11: float sum = 0.0f; 12: for(int i = 0; i < W; i++) 13: sum += a(row, i) * b(i, col); 14: c[idx] = sum; 15: }); 16: } To turn this into a tiled example, first we need to decide our tile size. Let's say we want each tile to be 16*16 (which assumes that we'll have at least 256 threads to process, and that c.grid.extent.size() is divisible by 256, and moreover that c.grid.extent[0] and c.grid.extent[1] are divisible by 16). So we insert at line 03 the tile size (which must be a compile time constant). 03: static const int TS = 16; ...then we need to tile the grid to have tiles where each one has 16*16 threads, so we change line 07 to be as follows 07: parallel_for_each(c.grid.tile<TS,TS>(), ...that means that our index now has to be a tiled_index with the same characteristics as the tiled_grid, so we change line 08 08: [=](tiled_index<TS, TS> t_idx) restrict(direct3d) { ...which means, without changing our core algorithm, we need to be using the global index that the tiled_index gives us access to, so we insert line 09 as follows 09: index<2> idx = t_idx.global; ...and now this code just works and it is tiled! Closing thoughts on part 1 The process we followed just shows the mechanical transformation that can take place from the simple model to the tiled model (think of this as step 1). In fact, when we wrote the matrix multiplication example originally, the compiler was doing this mechanical transformation under the covers for us (and it has additional smarts to deal with the cases where the total number of threads scheduled cannot be divisible by the tile size). The point is that the thread scheduling is always tiled, even when you use the non-tiled model. But with this mechanical transformation, we haven't gained anything… Hint: our goal with explicitly using the tiled model is to gain even more performance. In the next post, we'll evolve this further (beyond what the compiler can automatically do for us, in this first release), so you can see the full usage of the tiled model and its benefits… Comments about this post by Daniel Moth welcome at the original blog.

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  • OData &ndash; The easiest service I can create: now with updates

    - by Jon Dalberg
    The other day I created a simple NastyWord service exposed via OData. It was read-only and used an in-memory backing store for the words. Today I’ll modify it to use a file instead of a list and I’ll accept new nasty words by implementing IUpdatable directly. The first thing to do is enable the service to accept new entries. This is done at configuration time by adding the “WriteAppend” access rule: 1: public class NastyWords : DataService<NastyWordsDataSource> 2: { 3: // This method is called only once to initialize service-wide policies. 4: public static void InitializeService(DataServiceConfiguration config) 5: { 6: config.SetEntitySetAccessRule("*", EntitySetRights.AllRead | EntitySetRights.WriteAppend); 7: config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; 8: } 9: }   Next I placed a file, NastyWords.txt, in the “App_Data” folder and added a few *choice* words to start. This required one simple change to our NastyWordDataSource.cs file: 1: public NastyWordsDataSource() 2: { 3: UpdateFromSource(); 4: } 5:   6: private void UpdateFromSource() 7: { 8: var words = File.ReadAllLines(pathToFile); 9: NastyWords = (from w in words 10: select new NastyWord { Word = w }).AsQueryable(); 11: }   Nothing too shocking here, just reading each line from the NastyWords.txt file and exposing them. Next, I implemented IUpdatable which comes with a boat-load of methods. We don’t need all of them for now since we are only concerned with allowing new values. Here are the methods we must implement, all the others throw a NotImplementedException: 1: public object CreateResource(string containerName, string fullTypeName) 2: { 3: var nastyWord = new NastyWord(); 4: pendingUpdates.Add(nastyWord); 5: return nastyWord; 6: } 7:   8: public object ResolveResource(object resource) 9: { 10: return resource; 11: } 12:   13: public void SaveChanges() 14: { 15: var intersect = (from w in pendingUpdates 16: select w.Word).Intersect(from n in NastyWords 17: select n.Word); 18:   19: if (intersect.Count() > 0) 20: throw new DataServiceException(500, "duplicate entry"); 21:   22: var lines = from w in pendingUpdates 23: select w.Word; 24:   25: File.AppendAllLines(pathToFile, 26: lines, 27: Encoding.UTF8); 28:   29: pendingUpdates.Clear(); 30:   31: UpdateFromSource(); 32: } 33:   34: public void SetValue(object targetResource, string propertyName, object propertyValue) 35: { 36: targetResource.GetType().GetProperty(propertyName).SetValue(targetResource, propertyValue, null); 37: }   I use a simple list to contain the pending updates and only commit them when the “SaveChanges” method is called. Here’s the order these methods are called in our service during an insert: CreateResource – here we just instantiate a new NastyWord and stick a reference to it in our pending updates list. SetValue – this is where the “Word” property of the NastyWord instance is set. SaveChanges – get the list of pending updates, barfing on duplicates, write them to the file and clear our pending list. ResolveResource – the newly created resource will be returned directly here since we aren’t dealing with “handles” to objects but the actual objects themselves. Not too bad, eh? I didn’t find this documented anywhere but a little bit of digging in the OData spec and use of Fiddler made it pretty easy to figure out. Here is some client code which would add a new nasty word: 1: static void Main(string[] args) 2: { 3: var svc = new ServiceReference1.NastyWordsDataSource(new Uri("http://localhost.:60921/NastyWords.svc")); 4: svc.AddToNastyWords(new ServiceReference1.NastyWord() { Word = "shat" }); 5:   6: svc.SaveChanges(); 7: }   Here’s all of the code so far for to implement the service: 1: using System; 2: using System.Collections.Generic; 3: using System.Data.Services; 4: using System.Data.Services.Common; 5: using System.Linq; 6: using System.ServiceModel.Web; 7: using System.Web; 8: using System.IO; 9: using System.Text; 10:   11: namespace ONasty 12: { 13: [DataServiceKey("Word")] 14: public class NastyWord 15: { 16: public string Word { get; set; } 17: } 18:   19: public class NastyWordsDataSource : IUpdatable 20: { 21: private List<NastyWord> pendingUpdates = new List<NastyWord>(); 22: private string pathToFile = @"path to your\App_Data\NastyWords.txt"; 23:   24: public NastyWordsDataSource() 25: { 26: UpdateFromSource(); 27: } 28:   29: private void UpdateFromSource() 30: { 31: var words = File.ReadAllLines(pathToFile); 32: NastyWords = (from w in words 33: select new NastyWord { Word = w }).AsQueryable(); 34: } 35:   36: public IQueryable<NastyWord> NastyWords { get; private set; } 37:   38: public void AddReferenceToCollection(object targetResource, string propertyName, object resourceToBeAdded) 39: { 40: throw new NotImplementedException(); 41: } 42:   43: public void ClearChanges() 44: { 45: pendingUpdates.Clear(); 46: } 47:   48: public object CreateResource(string containerName, string fullTypeName) 49: { 50: var nastyWord = new NastyWord(); 51: pendingUpdates.Add(nastyWord); 52: return nastyWord; 53: } 54:   55: public void DeleteResource(object targetResource) 56: { 57: throw new NotImplementedException(); 58: } 59:   60: public object GetResource(IQueryable query, string fullTypeName) 61: { 62: throw new NotImplementedException(); 63: } 64:   65: public object GetValue(object targetResource, string propertyName) 66: { 67: throw new NotImplementedException(); 68: } 69:   70: public void RemoveReferenceFromCollection(object targetResource, string propertyName, object resourceToBeRemoved) 71: { 72: throw new NotImplementedException(); 73: } 74:   75: public object ResetResource(object resource) 76: { 77: throw new NotImplementedException(); 78: } 79:   80: public object ResolveResource(object resource) 81: { 82: return resource; 83: } 84:   85: public void SaveChanges() 86: { 87: var intersect = (from w in pendingUpdates 88: select w.Word).Intersect(from n in NastyWords 89: select n.Word); 90:   91: if (intersect.Count() > 0) 92: throw new DataServiceException(500, "duplicate entry"); 93:   94: var lines = from w in pendingUpdates 95: select w.Word; 96:   97: File.AppendAllLines(pathToFile, 98: lines, 99: Encoding.UTF8); 100:   101: pendingUpdates.Clear(); 102:   103: UpdateFromSource(); 104: } 105:   106: public void SetReference(object targetResource, string propertyName, object propertyValue) 107: { 108: throw new NotImplementedException(); 109: } 110:   111: public void SetValue(object targetResource, string propertyName, object propertyValue) 112: { 113: targetResource.GetType().GetProperty(propertyName).SetValue(targetResource, propertyValue, null); 114: } 115: } 116:   117: public class NastyWords : DataService<NastyWordsDataSource> 118: { 119: // This method is called only once to initialize service-wide policies. 120: public static void InitializeService(DataServiceConfiguration config) 121: { 122: config.SetEntitySetAccessRule("*", EntitySetRights.AllRead | EntitySetRights.WriteAppend); 123: config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2; 124: } 125: } 126: } Next time we’ll allow removing nasty words. Enjoy!

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  • Testing Workflows &ndash; Test-First

    - by Timothy Klenke
    Originally posted on: http://geekswithblogs.net/TimothyK/archive/2014/05/30/testing-workflows-ndash-test-first.aspxThis is the second of two posts on some common strategies for approaching the job of writing tests.  The previous post covered test-after workflows where as this will focus on test-first.  Each workflow presented is a method of attack for adding tests to a project.  The more tools in your tool belt the better.  So here is a partial list of some test-first methodologies. Ping Pong Ping Pong is a methodology commonly used in pair programing.  One developer will write a new failing test.  Then they hand the keyboard to their partner.  The partner writes the production code to get the test passing.  The partner then writes the next test before passing the keyboard back to the original developer. The reasoning behind this testing methodology is to facilitate pair programming.  That is to say that this testing methodology shares all the benefits of pair programming, including ensuring multiple team members are familiar with the code base (i.e. low bus number). Test Blazer Test Blazing, in some respects, is also a pairing strategy.  The developers don’t work side by side on the same task at the same time.  Instead one developer is dedicated to writing tests at their own desk.  They write failing test after failing test, never touching the production code.  With these tests they are defining the specification for the system.  The developer most familiar with the specifications would be assigned this task. The next day or later in the same day another developer fetches the latest test suite.  Their job is to write the production code to get those tests passing.  Once all the tests pass they fetch from source control the latest version of the test project to get the newer tests. This methodology has some of the benefits of pair programming, namely lowering the bus number.  This can be good way adding an extra developer to a project without slowing it down too much.  The production coder isn’t slowed down writing tests.  The tests are in another project from the production code, so there shouldn’t be any merge conflicts despite two developers working on the same solution. This methodology is also a good test for the tests.  Can another developer figure out what system should do just by reading the tests?  This question will be answered as the production coder works there way through the test blazer’s tests. Test Driven Development (TDD) TDD is a highly disciplined practice that calls for a new test and an new production code to be written every few minutes.  There are strict rules for when you should be writing test or production code.  You start by writing a failing (red) test, then write the simplest production code possible to get the code working (green), then you clean up the code (refactor).  This is known as the red-green-refactor cycle. The goal of TDD isn’t the creation of a suite of tests, however that is an advantageous side effect.  The real goal of TDD is to follow a practice that yields a better design.  The practice is meant to push the design toward small, decoupled, modularized components.  This is generally considered a better design that large, highly coupled ball of mud. TDD accomplishes this through the refactoring cycle.  Refactoring is only possible to do safely when tests are in place.  In order to use TDD developers must be trained in how to look for and repair code smells in the system.  Through repairing these sections of smelly code (i.e. a refactoring) the design of the system emerges. For further information on TDD, I highly recommend the series “Is TDD Dead?”.  It discusses its pros and cons and when it is best used. Acceptance Test Driven Development (ATDD) Whereas TDD focuses on small unit tests that concentrate on a small piece of the system, Acceptance Tests focuses on the larger integrated environment.  Acceptance Tests usually correspond to user stories, which come directly from the customer. The unit tests focus on the inputs and outputs of smaller parts of the system, which are too low level to be of interest to the customer. ATDD generally uses the same tools as TDD.  However, ATDD uses fewer mocks and test doubles than TDD. ATDD often complements TDD; they aren’t competing methods.  A full test suite will usually consist of a large number of unit (created via TDD) tests and a smaller number of acceptance tests. Behaviour Driven Development (BDD) BDD is more about audience than workflow.  BDD pushes the testing realm out towards the client.  Developers, managers and the client all work together to define the tests. Typically different tooling is used for BDD than acceptance and unit testing.  This is done because the audience is not just developers.  Tools using the Gherkin family of languages allow for test scenarios to be described in an English format.  Other tools such as MSpec or FitNesse also strive for highly readable behaviour driven test suites. Because these tests are public facing (viewable by people outside the development team), the terminology usually changes.  You can’t get away with the same technobabble you can with unit tests written in a programming language that only developers understand.  For starters, they usually aren’t called tests.  Usually they’re called “examples”, “behaviours”, “scenarios”, or “specifications”. This may seem like a very subtle difference, but I’ve seen this small terminology change have a huge impact on the acceptance of the process.  Many people have a bias that testing is something that comes at the end of a project.  When you say we need to define the tests at the start of the project many people will immediately give that a lower priority on the project schedule.  But if you say we need to define the specification or behaviour of the system before we can start, you’ll get more cooperation.   Keep these test-first and test-after workflows in your tool belt.  With them you’ll be able to find new opportunities to apply them.

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  • (Unity)Getting a mirrored mesh from my data structure

    - by Steve
    Here's the background: I'm in the beginning stages of an RTS game in Unity. I have a procedurally generated terrain with a perlin-noise height map, as well as a function to generate a river. The problem is that the graphical creation of the map is taking the data structure of the map and rotating it by 180 degrees. I noticed this problem when i was creating my rivers. I would set the River's height to flat, and noticed that the actual tiles that were flat in the graphical representation were flipped and mirrored. Here's 3 screenshots of the map from different angles: http://imgur.com/a/VLHHq As you can see, if you flipped (graphically) the river by 180 degrees on the z axis, it would fit where the terrain is flattened. I have a suspicion it is being caused by a misunderstanding on my part of how vertices work. Alas, here is a snippet of the code that is used: This code here creates a new array of Tile objects, which hold the information for each tile, including its type, coordinate, height, and it's 4 vertices public DTileMap (int size_x, int size_y) { this.size_x = size_x; this.size_y = size_y; //Initialize Map_Data Array of Tile Objects map_data = new Tile[size_x, size_y]; for (int j = 0; j < size_y; j++) { for (int i = 0; i < size_x; i++) { map_data [i, j] = new Tile (); map_data[i,j].coordinate.x = (int)i; map_data[i,j].coordinate.y = (int)j; map_data[i,j].vertices[0] = new Vector3 (i * GTileMap.TileMap.tileSize, map_data[i,j].Height, -j * GTileMap.TileMap.tileSize); map_data[i,j].vertices[1] = new Vector3 ((i+1) * GTileMap.TileMap.tileSize, map_data[i,j].Height, -(j) * GTileMap.TileMap.tileSize); map_data[i,j].vertices[2] = new Vector3 (i * GTileMap.TileMap.tileSize, map_data[i,j].Height, -(j-1) * GTileMap.TileMap.tileSize); map_data[i,j].vertices[3] = new Vector3 ((i+1) * GTileMap.TileMap.tileSize, map_data[i,j].Height, -(j-1) * GTileMap.TileMap.tileSize); } } This code sets the river tiles to height 0 foreach (Tile t in map_data) { if (t.realType == "Water") { t.vertices[0].y = 0f; t.vertices[1].y = 0f; t.vertices[2].y = 0f; t.vertices[3].y = 0f; } } And below is the code to generate the actual graphics from the data: public void BuildMesh () { DTileMap.DTileMap map = new DTileMap.DTileMap (size_x, size_z); int numTiles = size_x * size_z; int numTris = numTiles * 2; int vsize_x = size_x + 1; int vsize_z = size_z + 1; int numVerts = vsize_x * vsize_z; // Generate the mesh data Vector3[] vertices = new Vector3[ numVerts ]; Vector3[] normals = new Vector3[numVerts]; Vector2[] uv = new Vector2[numVerts]; int[] triangles = new int[ numTris * 3 ]; int x, z; for (z=0; z < vsize_z; z++) { for (x=0; x < vsize_x; x++) { normals [z * vsize_x + x] = Vector3.up; uv [z * vsize_x + x] = new Vector2 ((float)x / size_x, 1f - (float)z / size_z); } } for (z=0; z < vsize_z; z+=1) { for (x=0; x < vsize_x; x+=1) { if (x == vsize_x - 1 && z == vsize_z - 1) { vertices [z * vsize_x + x] = DTileMap.DTileMap.map_data [x - 1, z - 1].vertices [3]; } else if (z == vsize_z - 1) { vertices [z * vsize_x + x] = DTileMap.DTileMap.map_data [x, z - 1].vertices [2]; } else if (x == vsize_x - 1) { vertices [z * vsize_x + x] = DTileMap.DTileMap.map_data [x - 1, z].vertices [1]; } else { vertices [z * vsize_x + x] = DTileMap.DTileMap.map_data [x, z].vertices [0]; vertices [z * vsize_x + x+1] = DTileMap.DTileMap.map_data [x, z].vertices [1]; vertices [(z+1) * vsize_x + x] = DTileMap.DTileMap.map_data [x, z].vertices [2]; vertices [(z+1) * vsize_x + x+1] = DTileMap.DTileMap.map_data [x, z].vertices [3]; } } } } for (z=0; z < size_z; z++) { for (x=0; x < size_x; x++) { int squareIndex = z * size_x + x; int triOffset = squareIndex * 6; triangles [triOffset + 0] = z * vsize_x + x + 0; triangles [triOffset + 2] = z * vsize_x + x + vsize_x + 0; triangles [triOffset + 1] = z * vsize_x + x + vsize_x + 1; triangles [triOffset + 3] = z * vsize_x + x + 0; triangles [triOffset + 5] = z * vsize_x + x + vsize_x + 1; triangles [triOffset + 4] = z * vsize_x + x + 1; } } // Create a new Mesh and populate with the data Mesh mesh = new Mesh (); mesh.vertices = vertices; mesh.triangles = triangles; mesh.normals = normals; mesh.uv = uv; // Assign our mesh to our filter/renderer/collider MeshFilter mesh_filter = GetComponent<MeshFilter> (); MeshCollider mesh_collider = GetComponent<MeshCollider> (); mesh_filter.mesh = mesh; mesh_collider.sharedMesh = mesh; calculateMeshTangents (mesh); BuildTexture (map); } If this looks familiar to you, its because i got most of it from Quill18. I've been slowly adapting it for my uses. And please include any suggestions you have for my code. I'm still in the very early prototyping stage.

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  • ANTS CLR and Memory Profiler In Depth Review (Part 2 of 2 &ndash; Memory Profiler)

    - by ToStringTheory
    One of the things that people might not know about me, is my obsession to make my code as efficient as possible. Many people might not realize how much of a task or undertaking that this might be, but it is surely a task as monumental as climbing Mount Everest, except this time it is a challenge for the mind… In trying to make code efficient, there are many different factors that play a part – size of project or solution, tiers, language used, experience and training of the programmer, technologies used, maintainability of the code – the list can go on for quite some time. I spend quite a bit of time when developing trying to determine what is the best way to implement a feature to accomplish the efficiency that I look to achieve. One program that I have recently come to learn about – Red Gate ANTS Performance (CLR) and Memory profiler gives me tools to accomplish that job more efficiently as well. In this review, I am going to cover some of the features of the ANTS memory profiler set by compiling some hideous example code to test against. Notice As a member of the Geeks With Blogs Influencers program, one of the perks is the ability to review products, in exchange for a free license to the program. I have not let this affect my opinions of the product in any way, and Red Gate nor Geeks With Blogs has tried to influence my opinion regarding this product in any way. Introduction – Part 2 In my last post, I reviewed the feature packed Red Gate ANTS Performance Profiler.  Separate from the Red Gate Performance Profiler is the Red Gate ANTS Memory Profiler – a simple, easy to use utility for checking how your application is handling memory management…  A tool that I wish I had had many times in the past.  This post will be focusing on the ANTS Memory Profiler and its tool set. The memory profiler has a large assortment of features just like the Performance Profiler, with the new session looking nearly exactly alike: ANTS Memory Profiler Memory profiling is not something that I have to do very often…  In the past, the few cases I’ve had to find a memory leak in an application I have usually just had to trace the code of the operations being performed to look for oddities…  Sadly, I have come across more undisposed/non-using’ed IDisposable objects, usually from ADO.Net than I would like to ever see.  Support is not fun, however using ANTS Memory Profiler makes this task easier.  For this round of testing, I am going to use the same code from my previous example, using the WPF application. This time, I will choose the ‘Profile Memory’ option from the ANTS menu in Visual Studio, which launches the solution in its currently configured state/start-up project, and then launches the ANTS Memory Profiler to help.  It prepopulates all of the fields with the current project information, and all I have to do is select the ‘Start Profiling’ option. When the window comes up, it is actually quite barren, just giving ideas on how to work the profiler.  You start by getting to the point in your application that you want to profile, and then taking a ‘Memory Snapshot’.  This performs a full garbage collection, and snapshots the managed heap.  Using the same WPF app as before, I will go ahead and take a snapshot now. As you can see, ANTS is already giving me lots of information regarding the snapshot, however this is just a snapshot.  The whole point of the profiler is to perform an action, usually one where a memory problem is being noticed, and then take another snapshot and perform a diff between them to see what has changed.  I am going to go ahead and generate 5000 primes, and then take another snapshot: As you can see, ANTS is already giving me a lot of new information about this snapshot compared to the last.  Information such as difference in memory usage, fragmentation, class usage, etc…  If you take more snapshots, you can use the dropdown at the top to set your actual comparison snapshots. If you beneath the timeline, you will see a breadcrumb trail showing how best to approach profiling memory using ANTS.  When you first do the comparison, you start on the Summary screen.  You can either use the charts at the bottom, or switch to the class list screen to get to the next step.  Here is the class list screen: As you can see, it lists information about all of the instances between the snapshots, as well as at the bottom giving you a way to filter by telling ANTS what your problem is.  I am going to go ahead and select the Int16[] to look at the Instance Categorizer Using the instance categorizer, you can travel backwards to see where all of the instances are coming from.  It may be hard to see in this image, but hopefully the lightbox (click on it) will help: I can see that all of these instances are rooted to the application through the UI TextBlock control.  This image will probably be even harder to see, however using the ‘Instance Retention Graph’, you can trace an objects memory inheritance up the chain to see its roots as well.  This is a simple example, as this is simply a known element.  Usually you would be profiling an actual problem, and comparing those differences.  I know in the past, I have spotted a problem where a new context was created per page load, and it was rooted into the application through an event.  As the application began to grow, performance and reliability problems started to emerge.  A tool like this would have been a great way to identify the problem quickly. Overview Overall, I think that the Red Gate ANTS Memory Profiler is a great utility for debugging those pesky leaks.  3 Biggest Pros: Easy to use interface with lots of options for configuring profiling session Intuitive and helpful interface for drilling down from summary, to instance, to root graphs ANTS provides an API for controlling the profiler. Not many options, but still helpful. 2 Biggest Cons: Inability to automatically snapshot the memory by interval Lack of complete integration with Visual Studio via an extension panel Ratings Ease of Use (9/10) – I really do believe that they have brought simplicity to the once difficult task of memory profiling.  I especially liked how it stepped you further into the drilldown by directing you towards the best options. Effectiveness (10/10) – I believe that the profiler does EXACTLY what it purports to do.  Features (7/10) – A really great set of features all around in the application, however, I would like to see some ability for automatically triggering snapshots based on intervals or framework level items such as events. Customer Service (10/10) – My entire experience with Red Gate personnel has been nothing but good.  their people are friendly, helpful, and happy! UI / UX (9/10) – The interface is very easy to get around, and all of the options are easy to find.  With a little bit of poking around, you’ll be optimizing Hello World in no time flat! Overall (9/10) – Overall, I am happy with the Memory Profiler and its features, as well as with the service I received when working with the Red Gate personnel.  Thank you for reading up to here, or skipping ahead – I told you it would be shorter!  Please, if you do try the product, drop me a message and let me know what you think!  I would love to hear any opinions you may have on the product. Code Feel free to download the code I used above – download via DropBox

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  • How to begin? Windows 8 Development

    - by Dennis Vroegop
    Ok. I convinced you in my last post to do some Win8 development. You want a piece of that cake, or whatever your reasons may be. Good! Welcome to the club! Now let me ask you a question: what are you going to write? Ah. That’s the big one, isn’t it? What indeed? If you have been creating applications for computers before you’re in for quite a shock. The way people perceive apps on a tablet is quite different from what we know as applications. There’s a reason we call them apps instead of applications! Yes, technically they are applications but we don’t call them apps only because it sounds cool. The abbreviated form of the word applications itself is a pointer. Apps are small. Apps are focused. Apps are more lightweight. Apps do one thing but they do that one thing extremely good. In the ‘old’ days we wrote huge systems. We build ecosystems of services, screens, databases and more to create a system that provides value for the user. Think about it: what application do you use most at work? Can you in one sentence describe what it is, or what it does and yet still distinctively describe its purpose? I doubt you can. Let’s have a look at Outlouk. We all know it and we all love or hate it. But what is it? A mail program? No, there’s so much more there: calendar, contacts, RSS feeds and so on. Some call it a ‘collaboration’  application but that’s not really true as well. After all, why should a collaboration application give me my schedule for the day? I think the best way to describe Outlook is “client for Exchange”  although that isn’t accurate either. Anyway: Outlook is a great application but it’s not an ‘app’ and therefor not very suitable for WinRT. Ok. Disclaimer here: yes, you can write big applications for WinRT. Some will. But that’s not what 99.9% of the developers will do. So I am stating here that big applications are not meant for WinRT. If 0.01% of the developers think that this is nonsense then they are welcome to go ahead but for the majority here this is not what we’re talking about. So: Apps are small, lightweight and good at what they do but only at that. If you’re a Phone developer you already know that: Phone apps on any platform fit the description I have above. If you’ve ever worked in a large cooperation before you might have seen one of these before: the Mission Statement. It’s supposed to be a oneliner that sums up what the company is supposed to do. Funny enough: although this doesn’t work for large companies it does work for defining your app. A mission statement for an app describes what it does. If it doesn’t fit in the mission statement then your app is going to get to big and will fail. A statement like this should be in the following style “<your app name> is the best app to <describe single task>” Fill in the blanks, write it and go! Mmm.. not really. There are some things there we need to think about. But the statement is a very, very important one. If you cannot fit your app in that line you’re preparing to fail. Your app will become to big, its purpose will be unclear and it will be hard to use. People won’t download it and those who do will give it a bad rating therefor preventing that huge success you’ve been dreaming about. Stick to the statement! Ok, let’s give it a try: “PlanesAreCool” is the best app to do planespotting in the field. You might have seen these people along runways of airports: taking photographs of airplanes and noting down their numbers and arrival- and departure times. We are going to help them out with our great app! If you look at the statement, can you guess what it does? I bet you can. If you find out it isn’t clear enough of if it’s too broad, refine it. This is probably the most important step in the development of your app so give it enough time! So. We’ve got the statement. Print it out, stick it to the wall and look at it. What does it tell you? If you see this, what do you think the app does? Write that down. Sit down with some friends and talk about it. What do they expect from an app like this? Write that down as well. Brainstorm. Make a list of features. This is mine: Note planes Look up aircraft carriers Add pictures of that plane Look up airfields Notify friends of new spots Look up details of a type of plane Plot a graph with arrival and departure times Share new spots on social media Look up history of a particular aircraft Compare your spots with friends Write down arrival times Write down departure times Write down wind conditions Write down the runway they take Look up weather conditions for next spotting day Invite friends to join you for a day of spotting. Now, I must make it clear that I am not a planespotter nor do I know what one does. So if the above list makes no sense, I apologize. There is a lesson: write apps for stuff you know about…. First of all, let’s look at our statement and then go through the list of features. Remove everything that has nothing to do with that statement! If you end up with an empty list, try again with both steps. Note planes Look up aircraft carriers Add pictures of that plane Look up airfields Notify friends of new spots Look up details of a type of plane Plot a graph with arrival and departure times Share new spots on social media Look up history of a particular aircraft Compare your spots with friends Write down arrival times Write down departure times Write down wind conditions Write down the runway they take Look up weather conditions for next spotting day Invite friends to join you for a day of spotting. That's better. The things I removed could be pretty useful to a plane spotter and could be fun to write. But do they match the statement? I said that the app is for spotting in the field, so “look up airfields” doesn’t belong there: I know where I am so why look it up? And the same goes for inviting friends or looking up the weather conditions for tomorrow. I am at the airfield right now, looking through my binoculars at the planes. I know the weather now and I don’t care about tomorrow. If you feel the items you’ve crossed out are valuable, then why not write another app? One that says “SpotNoter” is the best app for preparing a day of spotting with my friends. That’s a different app! Remember: Win8 apps are small and very good at doing ONE thing, and one thing only! If you have made that list, it’s time to prepare the navigation of your app. The navigation is how users see your app and how they use it. We’ll do that next time!

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  • Portable class libraries and fetching JSON

    - by Jeff
    After much delay, we finally have the Windows Phone 8 SDK to go along with the Windows 8 Store SDK, or whatever ridiculous name they’re giving it these days. (Seriously… that no one could come up with a suitable replacement for “metro” is disappointing in an otherwise exciting set of product launches.) One of the neat-o things is the potential for code reuse, particularly across Windows 8 and Windows Phone 8 apps. This is accomplished in part with portable class libraries, which allow you to share code between different types of projects. With some other techniques and quasi-hacks, you can share some amount of code, and I saw it mentioned in one of the Build videos that they’re seeing as much as 70% code reuse. Not bad. However, I’ve already hit a super annoying snag. It appears that the HttpClient class, with its idiot-proof async goodness, is not included in the Windows Phone 8 class libraries. Shock, gasp, horror, disappointment, etc. The delay in releasing it already caused dismay among developers, and I’m sure this won’t help. So I started refactoring some code I already had for a Windows 8 Store app (ugh) to accommodate the use of HttpWebRequest instead. I haven’t tried it in a Windows Phone 8 project beyond compiling, but it appears to work. I used this StackOverflow answer as a starting point since it’s been a long time since I used HttpWebRequest, and keep in mind that it has no exception handling. It needs refinement. The goal here is to new up the client, and call a method that returns some deserialized JSON objects from the Intertubes. Adding facilities for headers or cookies is probably a good next step. You need to use NuGet for a Json.NET reference. So here’s the start: using System.Net; using System.Threading.Tasks; using Newtonsoft.Json; using System.IO; namespace MahProject {     public class ServiceClient<T> where T : class     {         public ServiceClient(string url)         {             _url = url;         }         private readonly string _url;         public async Task<T> GetResult()         {             var response = await MakeAsyncRequest(_url);             var result = JsonConvert.DeserializeObject<T>(response);             return result;         }         public static Task<string> MakeAsyncRequest(string url)         {             var request = (HttpWebRequest)WebRequest.Create(url);             request.ContentType = "application/json";             Task<WebResponse> task = Task.Factory.FromAsync(                 request.BeginGetResponse,                 asyncResult => request.EndGetResponse(asyncResult),                 null);             return task.ContinueWith(t => ReadStreamFromResponse(t.Result));         }         private static string ReadStreamFromResponse(WebResponse response)         {             using (var responseStream = response.GetResponseStream())                 using (var reader = new StreamReader(responseStream))                 {                     var content = reader.ReadToEnd();                     return content;                 }         }     } } Calling it in some kind of repository class may look like this, if you wanted to return an array of Park objects (Park model class omitted because it doesn’t matter): public class ParkRepo {     public async Task<Park[]> GetAllParks()     {         var client = new ServiceClient<Park[]>(http://superfoo/endpoint);         return await client.GetResult();     } } And then from inside your WP8 or W8S app (see what I did there?), when you load state or do some kind of UI event handler (making sure the method uses the async keyword): var parkRepo = new ParkRepo(); var results = await parkRepo.GetAllParks(); // bind results to some UI or observable collection or something Hopefully this saves you a little time.

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  • Getting a mirrored mesh from my data structure

    - by Steve
    Here's the background: I'm in the beginning stages of an RTS game in Unity. I have a procedurally generated terrain with a perlin-noise height map, as well as a function to generate a river. The problem is that the graphical creation of the map is taking the data structure of the map and rotating it by 180 degrees. I noticed this problem when I was creating my rivers. I would set the River's height to flat, and noticed that the actual tiles that were flat in the graphical representation were flipped and mirrored. Here's 3 screenshots of the map from different angles: http://imgur.com/a/VLHHq As you can see, if you flipped (graphically) the river by 180 degrees on the z axis, it would fit where the terrain is flattened. I have a suspicion it is being caused by a misunderstanding on my part of how vertices work. Alas, here is a snippet of the code that is used: This code here creates a new array of Tile objects, which hold the information for each tile, including its type, coordinate, height, and it's 4 vertices public DTileMap (int size_x, int size_y) { this.size_x = size_x; this.size_y = size_y; //Initialize Map_Data Array of Tile Objects map_data = new Tile[size_x, size_y]; for (int j = 0; j < size_y; j++) { for (int i = 0; i < size_x; i++) { map_data [i, j] = new Tile (); map_data[i,j].coordinate.x = (int)i; map_data[i,j].coordinate.y = (int)j; map_data[i,j].vertices[0] = new Vector3 (i * GTileMap.TileMap.tileSize, map_data[i,j].Height, -j * GTileMap.TileMap.tileSize); map_data[i,j].vertices[1] = new Vector3 ((i+1) * GTileMap.TileMap.tileSize, map_data[i,j].Height, -(j) * GTileMap.TileMap.tileSize); map_data[i,j].vertices[2] = new Vector3 (i * GTileMap.TileMap.tileSize, map_data[i,j].Height, -(j-1) * GTileMap.TileMap.tileSize); map_data[i,j].vertices[3] = new Vector3 ((i+1) * GTileMap.TileMap.tileSize, map_data[i,j].Height, -(j-1) * GTileMap.TileMap.tileSize); } } This code sets the river tiles to height 0 foreach (Tile t in map_data) { if (t.realType == "Water") { t.vertices[0].y = 0f; t.vertices[1].y = 0f; t.vertices[2].y = 0f; t.vertices[3].y = 0f; } } And below is the code to generate the actual graphics from the data: public void BuildMesh () { DTileMap.DTileMap map = new DTileMap.DTileMap (size_x, size_z); int numTiles = size_x * size_z; int numTris = numTiles * 2; int vsize_x = size_x + 1; int vsize_z = size_z + 1; int numVerts = vsize_x * vsize_z; // Generate the mesh data Vector3[] vertices = new Vector3[ numVerts ]; Vector3[] normals = new Vector3[numVerts]; Vector2[] uv = new Vector2[numVerts]; int[] triangles = new int[ numTris * 3 ]; int x, z; for (z=0; z < vsize_z; z++) { for (x=0; x < vsize_x; x++) { normals [z * vsize_x + x] = Vector3.up; uv [z * vsize_x + x] = new Vector2 ((float)x / size_x, 1f - (float)z / size_z); } } for (z=0; z < vsize_z; z+=1) { for (x=0; x < vsize_x; x+=1) { if (x == vsize_x - 1 && z == vsize_z - 1) { vertices [z * vsize_x + x] = DTileMap.DTileMap.map_data [x - 1, z - 1].vertices [3]; } else if (z == vsize_z - 1) { vertices [z * vsize_x + x] = DTileMap.DTileMap.map_data [x, z - 1].vertices [2]; } else if (x == vsize_x - 1) { vertices [z * vsize_x + x] = DTileMap.DTileMap.map_data [x - 1, z].vertices [1]; } else { vertices [z * vsize_x + x] = DTileMap.DTileMap.map_data [x, z].vertices [0]; vertices [z * vsize_x + x+1] = DTileMap.DTileMap.map_data [x, z].vertices [1]; vertices [(z+1) * vsize_x + x] = DTileMap.DTileMap.map_data [x, z].vertices [2]; vertices [(z+1) * vsize_x + x+1] = DTileMap.DTileMap.map_data [x, z].vertices [3]; } } } } for (z=0; z < size_z; z++) { for (x=0; x < size_x; x++) { int squareIndex = z * size_x + x; int triOffset = squareIndex * 6; triangles [triOffset + 0] = z * vsize_x + x + 0; triangles [triOffset + 2] = z * vsize_x + x + vsize_x + 0; triangles [triOffset + 1] = z * vsize_x + x + vsize_x + 1; triangles [triOffset + 3] = z * vsize_x + x + 0; triangles [triOffset + 5] = z * vsize_x + x + vsize_x + 1; triangles [triOffset + 4] = z * vsize_x + x + 1; } } // Create a new Mesh and populate with the data Mesh mesh = new Mesh (); mesh.vertices = vertices; mesh.triangles = triangles; mesh.normals = normals; mesh.uv = uv; // Assign our mesh to our filter/renderer/collider MeshFilter mesh_filter = GetComponent<MeshFilter> (); MeshCollider mesh_collider = GetComponent<MeshCollider> (); mesh_filter.mesh = mesh; mesh_collider.sharedMesh = mesh; calculateMeshTangents (mesh); BuildTexture (map); } If this looks familiar to you, its because i got most of it from Quill18. I've been slowly adapting it for my uses. And please include any suggestions you have for my code. I'm still in the very early prototyping stage.

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  • Entity Framework 6: Alpha2 Now Available

    - by ScottGu
    The Entity Framework team recently announced the 2nd alpha release of EF6.   The alpha 2 package is available for download from NuGet. Since this is a pre-release package make sure to select “Include Prereleases” in the NuGet package manager, or execute the following from the package manager console to install it: PM> Install-Package EntityFramework -Pre This week’s alpha release includes a bunch of great improvements in the following areas: Async language support is now available for queries and updates when running on .NET 4.5. Custom conventions now provide the ability to override the default conventions that Code First uses for mapping types, properties, etc. to your database. Multi-tenant migrations allow the same database to be used by multiple contexts with full Code First Migrations support for independently evolving the model backing each context. Using Enumerable.Contains in a LINQ query is now handled much more efficiently by EF and the SQL Server provider resulting greatly improved performance. All features of EF6 (except async) are available on both .NET 4 and .NET 4.5. This includes support for enums and spatial types and the performance improvements that were previously only available when using .NET 4.5. Start-up time for many large models has been dramatically improved thanks to improved view generation performance. Below are some additional details about a few of the improvements above: Async Support .NET 4.5 introduced the Task-Based Asynchronous Pattern that uses the async and await keywords to help make writing asynchronous code easier. EF 6 now supports this pattern. This is great for ASP.NET applications as database calls made through EF can now be processed asynchronously – avoiding any blocking of worker threads. This can increase scalability on the server by allowing more requests to be processed while waiting for the database to respond. The following code shows an MVC controller that is querying a database for a list of location entities:     public class HomeController : Controller     {         LocationContext db = new LocationContext();           public async Task<ActionResult> Index()         {             var locations = await db.Locations.ToListAsync();               return View(locations);         }     } Notice above the call to the new ToListAsync method with the await keyword. When the web server reaches this code it initiates the database request, but rather than blocking while waiting for the results to come back, the thread that is processing the request returns to the thread pool, allowing ASP.NET to process another incoming request with the same thread. In other words, a thread is only consumed when there is actual processing work to do, allowing the web server to handle more concurrent requests with the same resources. A more detailed walkthrough covering async in EF is available with additional information and examples. Also a walkthrough is available showing how to use async in an ASP.NET MVC application. Custom Conventions When working with EF Code First, the default behavior is to map .NET classes to tables using a set of conventions baked into EF. For example, Code First will detect properties that end with “ID” and configure them automatically as primary keys. However, sometimes you cannot or do not want to follow those conventions and would rather provide your own. For example, maybe your primary key properties all end in “Key” instead of “Id”. Custom conventions allow the default conventions to be overridden or new conventions to be added so that Code First can map by convention using whatever rules make sense for your project. The following code demonstrates using custom conventions to set the precision of all decimals to 5. As with other Code First configuration, this code is placed in the OnModelCreating method which is overridden on your derived DbContext class:         protected override void OnModelCreating(DbModelBuilder modelBuilder)         {             modelBuilder.Properties<decimal>()                 .Configure(x => x.HasPrecision(5));           } But what if there are a couple of places where a decimal property should have a different precision? Just as with all the existing Code First conventions, this new convention can be overridden for a particular property simply by explicitly configuring that property using either the fluent API or a data annotation. A more detailed description of custom code first conventions is available here. Community Involvement I blogged a while ago about EF being released under an open source license.  Since then a number of community members have made contributions and these are included in EF6 alpha 2. Two examples of community contributions are: AlirezaHaghshenas contributed a change that increases the startup performance of EF for larger models by improving the performance of view generation. The change means that it is less often necessary to use of pre-generated views. UnaiZorrilla contributed the first community feature to EF: the ability to load all Code First configuration classes in an assembly with a single method call like the following: protected override void OnModelCreating(DbModelBuilder modelBuilder) {        modelBuilder.Configurations            .AddFromAssembly(typeof(LocationContext).Assembly); } This code will find and load all the classes that inherit from EntityTypeConfiguration<T> or ComplexTypeConfiguration<T> in the assembly where LocationContext is defined. This reduces the amount of coupling between the context and Code First configuration classes, and is also a very convenient shortcut for large models. Other upcoming features coming in EF 6 Lots of information about the development of EF6 can be found on the EF CodePlex site, including a roadmap showing the other features that are planned for EF6. One of of the nice upcoming features is connection resiliency, which will automate the process of retying database operations on transient failures common in cloud environments and with databases such as the Windows Azure SQL Database. Another often requested feature that will be included in EF6 is the ability to map stored procedures to query and update operations on entities when using Code First. Summary EF6 is the first open source release of Entity Framework being developed in CodePlex. The alpha 2 preview release of EF6 is now available on NuGet, and contains some really great features for you to try. The EF team are always looking for feedback from developers - especially on the new features such as custom Code First conventions and async support. To provide feedback you can post a comment on the EF6 alpha 2 announcement post, start a discussion or file a bug on the CodePlex site. Hope this helps, Scott P.S. In addition to blogging, I am also now using Twitter for quick updates and to share links. Follow me at: twitter.com/scottgu

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  • LINQ – SequenceEqual() method

    - by nmarun
    I have been looking at LINQ extension methods and have blogged about what I learned from them in my blog space. Next in line is the SequenceEqual() method. Here’s the description about this method: “Determines whether two sequences are equal by comparing the elements by using the default equality comparer for their type.” Let’s play with some code: 1: int[] numbers = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; 2: // int[] numbersCopy = numbers; 3: int[] numbersCopy = { 5, 4, 1, 3, 9, 8, 6, 7, 2, 0 }; 4:  5: Console.WriteLine(numbers.SequenceEqual(numbersCopy)); This gives an output of ‘True’ – basically compares each of the elements in the two arrays and returns true in this case. The result is same even if you uncomment line 2 and comment line 3 (I didn’t need to say that now did I?). So then what happens for custom types? For this, I created a Product class with the following definition: 1: class Product 2: { 3: public int ProductId { get; set; } 4: public string Name { get; set; } 5: public string Category { get; set; } 6: public DateTime MfgDate { get; set; } 7: public Status Status { get; set; } 8: } 9:  10: public enum Status 11: { 12: Active = 1, 13: InActive = 2, 14: OffShelf = 3, 15: } In my calling code, I’m just adding a few product items: 1: private static List<Product> GetProducts() 2: { 3: return new List<Product> 4: { 5: new Product 6: { 7: ProductId = 1, 8: Name = "Laptop", 9: Category = "Computer", 10: MfgDate = new DateTime(2003, 4, 3), 11: Status = Status.Active, 12: }, 13: new Product 14: { 15: ProductId = 2, 16: Name = "Compact Disc", 17: Category = "Water Sport", 18: MfgDate = new DateTime(2009, 12, 3), 19: Status = Status.InActive, 20: }, 21: new Product 22: { 23: ProductId = 3, 24: Name = "Floppy", 25: Category = "Computer", 26: MfgDate = new DateTime(1993, 3, 7), 27: Status = Status.OffShelf, 28: }, 29: }; 30: } Now for the actual check: 1: List<Product> products1 = GetProducts(); 2: List<Product> products2 = GetProducts(); 3:  4: Console.WriteLine(products1.SequenceEqual(products2)); This one returns ‘False’ and the reason is simple – this one checks for reference equality and the products in the both the lists get different ‘memory addresses’ (sounds like I’m talking in ‘C’). In order to modify this behavior and return a ‘True’ result, we need to modify the Product class as follows: 1: class Product : IEquatable<Product> 2: { 3: public int ProductId { get; set; } 4: public string Name { get; set; } 5: public string Category { get; set; } 6: public DateTime MfgDate { get; set; } 7: public Status Status { get; set; } 8:  9: public override bool Equals(object obj) 10: { 11: return Equals(obj as Product); 12: } 13:  14: public bool Equals(Product other) 15: { 16: //Check whether the compared object is null. 17: if (ReferenceEquals(other, null)) return false; 18:  19: //Check whether the compared object references the same data. 20: if (ReferenceEquals(this, other)) return true; 21:  22: //Check whether the products' properties are equal. 23: return ProductId.Equals(other.ProductId) 24: && Name.Equals(other.Name) 25: && Category.Equals(other.Category) 26: && MfgDate.Equals(other.MfgDate) 27: && Status.Equals(other.Status); 28: } 29:  30: // If Equals() returns true for a pair of objects 31: // then GetHashCode() must return the same value for these objects. 32: // read why in the following articles: 33: // http://geekswithblogs.net/akraus1/archive/2010/02/28/138234.aspx 34: // http://stackoverflow.com/questions/371328/why-is-it-important-to-override-gethashcode-when-equals-method-is-overriden-in-c 35: public override int GetHashCode() 36: { 37: //Get hash code for the ProductId field. 38: int hashProductId = ProductId.GetHashCode(); 39:  40: //Get hash code for the Name field if it is not null. 41: int hashName = Name == null ? 0 : Name.GetHashCode(); 42:  43: //Get hash code for the ProductId field. 44: int hashCategory = Category.GetHashCode(); 45:  46: //Get hash code for the ProductId field. 47: int hashMfgDate = MfgDate.GetHashCode(); 48:  49: //Get hash code for the ProductId field. 50: int hashStatus = Status.GetHashCode(); 51: //Calculate the hash code for the product. 52: return hashProductId ^ hashName ^ hashCategory & hashMfgDate & hashStatus; 53: } 54:  55: public static bool operator ==(Product a, Product b) 56: { 57: // Enable a == b for null references to return the right value 58: if (ReferenceEquals(a, b)) 59: { 60: return true; 61: } 62: // If one is null and the other not. Remember a==null will lead to Stackoverflow! 63: if (ReferenceEquals(a, null)) 64: { 65: return false; 66: } 67: return a.Equals((object)b); 68: } 69:  70: public static bool operator !=(Product a, Product b) 71: { 72: return !(a == b); 73: } 74: } Now THAT kinda looks overwhelming. But lets take one simple step at a time. Ok first thing you’ve noticed is that the class implements IEquatable<Product> interface – the key step towards achieving our goal. This interface provides us with an ‘Equals’ method to perform the test for equality with another Product object, in this case. This method is called in the following situations: when you do a ProductInstance.Equals(AnotherProductInstance) and when you perform actions like Contains<T>, IndexOf() or Remove() on your collection Coming to the Equals method defined line 14 onwards. The two ‘if’ blocks check for null and referential equality using the ReferenceEquals() method defined in the Object class. Line 23 is where I’m doing the actual check on the properties of the Product instances. This is what returns the ‘True’ for us when we run the application. I have also overridden the Object.Equals() method which calls the Equals() method of the interface. One thing to remember is that anytime you override the Equals() method, its’ a good practice to override the GetHashCode() method and overload the ‘==’ and the ‘!=’ operators. For detailed information on this, please read this and this. Since we’ve overloaded the operators as well, we get ‘True’ when we do actions like: 1: Console.WriteLine(products1.Contains(products2[0])); 2: Console.WriteLine(products1[0] == products2[0]); This completes the full circle on the SequenceEqual() method. See the code used in the article here.

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  • How to trace a function array argument in DTrace

    - by uejio
    I still use dtrace just about every day in my job and found that I had to print an argument to a function which was an array of strings.  The array was variable length up to about 10 items.  I'm not sure if the is the right way to do it, but it seems to work and is not too painful if the array size is small.Here's an example.  Suppose in your application, you have the following function, where n is number of item in the array s.void arraytest(int n, char **s){    /* Loop thru s[0] to s[n-1] */}How do you use DTrace to print out the values of s[i] or of s[0] to s[n-1]?  DTrace does not have if-then blocks or for loops, so you can't do something like:    for i=0; i<arg0; i++        trace arg1[i]; It turns out that you can use probe ordering as a kind of iterator. Probes with the same name will fire in the order that they appear in the script, so I can save the value of "n" in the first probe and then use it as part of the predicate of the next probe to determine if the other probe should fire or not.  So the first probe for tracing the arraytest function is:pid$target::arraytest:entry{    self->n = arg0;}Then, if I want to print out the first few items of the array, I first check the value of n.  If it's greater than the index that I want to print out, then I can print that index.  For example, if I want to print out the 3rd element of the array, I would do something like:pid$target::arraytest:entry/self->n > 2/{    printf("%s",stringof(arg1 + 2 * sizeof(pointer)));}Actually, that doesn't quite work because arg1 is a pointer to an array of pointers and needs to be copied twice from the user process space to the kernel space (which is where dtrace is). Also, the sizeof(char *) is 8, but for some reason, I have to use 4 which is the sizeof(uint32_t). (I still don't know how that works.)  So, the script that prints the 3rd element of the array should look like:pid$target::arraytest:entry{    /* first, save the size of the array so that we don't get            invalid address errors when indexing arg1+n. */    self->n = arg0;}pid$target::arraytest:entry/self->n > 2/{    /* print the 3rd element (index = 2) of the second arg. */    i = 2;    size = 4;    self->a_t = copyin(arg1+size*i,size);    printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));}If your array is large, then it's quite painful since you have to write one probe for every array index.  For example, here's the full script for printing the first 5 elements of the array:#!/usr/sbin/dtrace -spid$target::arraytest:entry{        /* first, save the size of the array so that we don't get           invalid address errors when indexing arg1+n. */        self->n = arg0;}pid$target::arraytest:entry/self->n > 0/{        i = 0;        size = sizeof(uint32_t);        self->a_t = copyin(arg1+size*i,size);        printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));}pid$target::arraytest:entry/self->n > 1/{        i = 1;        size = sizeof(uint32_t);        self->a_t = copyin(arg1+size*i,size);        printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));}pid$target::arraytest:entry/self->n > 2/{        i = 2;        size = sizeof(uint32_t);        self->a_t = copyin(arg1+size*i,size);        printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));}pid$target::arraytest:entry/self->n > 3/{        i = 3;        size = sizeof(uint32_t);        self->a_t = copyin(arg1+size*i,size);        printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));}pid$target::arraytest:entry/self->n > 4/{        i = 4;        size = sizeof(uint32_t);        self->a_t = copyin(arg1+size*i,size);        printf("%s: a[%d]=%s",probefunc,i,copyinstr(*(uint32_t *)self->a_t));} If the array is large, then your script will also have to be very long to print out all values of the array.

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  • A Linker Resolution Problem in a C++ Program

    - by Vlad
    We have two source files, a.cpp and b.cpp and a header file named constructions.h. We define a simple C++ class with the same name (class M, for instance) in each source file, respectively. The file a.cpp looks like this: #include "iostream" #include "constructions.h" class M { int i; public: M(): i( -1 ) { cout << "M() from a.cpp" << endl; } M( int a ) : i( a ) { cout << "M(int) from a.cpp, i: " << i << endl; } M( const M& b ) { i = b.i; cout << "M(M&) from a.cpp, i: " << i << endl; } M& operator = ( M& b ) { i = b.i; cout << "M::operator =(), i: " << i << endl; return *this; } virtual ~M(){ cout << "M::~M() from a.cpp" << endl; } operator int() { cout << "M::operator int() from a.cpp" << endl; return i; } }; void test1() { cout << endl << "Example 1" << endl; M b1; cout << "b1: " << b1 << endl; cout << endl << "Example 2" << endl; M b2 = 5; cout << "b2: " << b2 << endl; cout << endl << "Example 3" << endl; M b3(6); cout << "b3: " << b3 << endl; cout << endl << "Example 4" << endl; M b4 = b1; cout << "b4: " << b4 << endl; cout << endl << "Example 5" << endl; M b5; b5 = b2; cout << "b5: " << b5 << endl; } int main(int argc, char* argv[]) { test1(); test2(); cin.get(); return 0; } The file b.cpp looks like this: #include "iostream" #include "constructions.h" class M { public: M() { cout << "M() from b.cpp" << endl; } ~M() { cout << "M::~M() from b.cpp" << endl; } }; void test2() { M m; } Finally, the file constructions.h contains only the declaration of the function "test2()" (which is defined in "b.cpp"), so that it can be used in "a.cpp": using namespace std; void test2(); We compiled and linked these three files using either VS2005 or the GNU 4.1.0 compiler and the 2.16.91 ld linker under Suse. The results are surprising and different between the two build environments. But in both cases it looks like the linker gets confused about which definition of the class M it should use. If we comment out the definition of test2() from b.cpp and its invocation from a.cpp, then all the C++ objects created in test1() are of the type M defined in a.cpp and the program executes normally under Windows and Suse. Here is the run output under Windows: Example 1 M() from a.cpp M::operator int() from a.cpp b1: -1 Example 2 M(int) from a.cpp, i: 5 M::operator int() from a.cpp b2: 5 Example 3 M(int) from a.cpp, i: 6 M::operator int() from a.cpp b3: 6 Example 4 M(M&) from a.cpp, i: -1 M::operator int() from a.cpp b4: -1 Example 5 M() from a.cpp M::operator =(), i: 5 M::operator int() from a.cpp b5: 5 M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp If we enable the definition of test2() in "b.cpp" but comment out its invocation from main(), then the results are different. Under Suse, the C++ objects created in test1() are still of the type M defined in a.cpp and the program still seems to execute normally. The VS2005 versions behave differently in Debug or Release mode: in Debug mode, the program still seems to execute normally, but in Release mode, b1 and b5 are of the type M defined in b.cpp (as the constructor invocation proves), although the other member functions called (including the destructor), belong to M defined in a.cpp. Here is the run output for the executable built in Release mode: Example 1 M() from b.cpp M::operator int() from a.cpp b1: 4206872 Example 2 M(int) from a.cpp, i: 5 M::operator int() from a.cpp b2: 5 Example 3 M(int) from a.cpp, i: 6 M::operator int() from a.cpp b3: 6 Example 4 M(M&) from a.cpp, i: 4206872 M::operator int() from a.cpp b4: 4206872 Example 5 M() from b.cpp M::operator =(), i: 5 M::operator int() from a.cpp b5: 5 M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp Finally, if we allow the call to test2() from main, the program misbehaves in all circumstances (that is under Suse and under Windows in both Debug and Release modes). The Windows-Debug version finds a memory corruption around the variable m, defined in test2(). Here is the Windows output in Release mode (test2() seems to have created an instance of M defined in b.cpp): Example 1 M() from b.cpp M::operator int() from a.cpp b1: 4206872 Example 2 M(int) from a.cpp, i: 5 M::operator int() from a.cpp b2: 5 Example 3 M(int) from a.cpp, i: 6 M::operator int() from a.cpp b3: 6 Example 4 M(M&) from a.cpp, i: 4206872 M::operator int() from a.cpp b4: 4206872 Example 5 M() from b.cpp M::operator =(), i: 5 M::operator int() from a.cpp b5: 5 M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M() from b.cpp M::~M() from b.cpp And here is the Suse output. The objects created in test1() are of the type M defined in a.cpp but the object created in test2() is also of the type M defined in a.cpp, unlike the object created under Windows which is of the type M defined in b.cpp. The program crashed in the end: Example 1 M() from a.cpp M::operator int() from a.cpp b1: -1 Example 2 M(int) from a.cpp, i: 5 M::operator int() from a.cpp b2: 5 Example 3 M(int) from a.cpp, i: 6 M::operator int() from a.cpp b3: 6 Example 4 M(M&) from a.cpp, i: -1 M::operator int() from a.cpp b4: -1 Example 5 M() from a.cpp M::operator =(), i: 5 M::operator int() from a.cpp b5: 5 M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M::~M() from a.cpp M() from a.cpp M::~M() from a.cpp Segmentation fault (core dumped) I couldn't make the angle brackets appear using Markdown, so I used quotes around the header file name iostream. Otherwise, the code could be copied verbatim and tried. It is purely scholastic. The statement cin.get() at the end of main() was included just to facilitate running the program directly from VS2005 (cause it to display the output window until we could analyze the output). We are looking for a software engineer in Sunnyvale, CA and may offer that position to the programmer capable of providing an intelligent and comprehensive explanation of these anomalies. I can be contacted at [email protected].

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  • How to display data stored in core data in a table view?

    - by Dipanjan Dutta
    Hello All, I have developed a core data model for my application. I need to display the saved data into a table view. For my app I have selected split view controller. I am writing down my codes below. Please help me in this regard and write me the code that needs to be added. This is very important as my continuation in my company depends on this. #import "RootViewController.h" #import "DetailViewController.h" #import "AddViewController.h" #import "EmployeeDetailsAppDelegate.h" /* This template does not ensure user interface consistency during editing operations in the table view. You must implement appropriate methods to provide the user experience you require. */ @interface RootViewController () - (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath; @end @implementation RootViewController @synthesize detailViewController, fetchedResultsController, managedObjectContext, results, empName; #pragma mark - #pragma mark View lifecycle - (void)viewDidLoad { results = [[NSMutableDictionary alloc]init]; [results setObject:empName.text forKey:@"EmployeeName"]; [self.tableView reloadData]; [super viewDidLoad]; } /* - (void)viewWillAppear:(BOOL)animated { [super viewWillAppear:animated]; } */ /* - (void)viewDidAppear:(BOOL)animated { [super viewDidAppear:animated]; } */ /* - (void)viewWillDisappear:(BOOL)animated { [super viewWillDisappear:animated]; } */ /* - (void)viewDidDisappear:(BOOL)animated { [super viewDidDisappear:animated]; } */ - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Ensure that the view controller supports rotation and that the split view can therefore show in both portrait and landscape. return YES; } - (void)configureCell:(UITableViewCell *)cell atIndexPath:(NSIndexPath *)indexPath { NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath]; cell.textLabel.text = [[managedObject valueForKey:@"EmployeeName"] description]; } #pragma mark - #pragma mark Add a new object - (void)insertNewObject:(id)sender { AddViewController *add = [[AddViewController alloc]initWithNibName:@"AddViewController" bundle:nil]; self.modalPresentationStyle = UIModalPresentationFormSheet; add.wantsFullScreenLayout = NO; [self presentModalViewController:add animated:YES]; [add release]; } #pragma mark - #pragma mark Table view data source - (NSInteger)numberOfSectionsInTableView:(UITableView *)tableView { return 1; } - (NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section { return 1; } - (UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath { static NSString *CellIdentifier = @"Cell"; UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:CellIdentifier]; if (cell == nil) { cell = [[[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:CellIdentifier] autorelease]; } // Configure the cell. NSManagedObject *managedObject = [self.fetchedResultsController objectAtIndexPath:indexPath]; cell.textLabel.text = [[managedObject valueForKey:@"EmployeeName"] description]; return cell; } - (void)tableView:(UITableView *)tableView commitEditingStyle:(UITableViewCellEditingStyle)editingStyle forRowAtIndexPath:(NSIndexPath *)indexPath { if (editingStyle == UITableViewCellEditingStyleDelete) { // Delete the managed object. NSManagedObject *objectToDelete = [self.fetchedResultsController objectAtIndexPath:indexPath]; if (self.detailViewController.detailItem == objectToDelete) { self.detailViewController.detailItem = nil; } NSManagedObjectContext *context = [self.fetchedResultsController managedObjectContext]; [context deleteObject:objectToDelete]; NSError *error; if (![context save:&error]) { /* Replace this implementation with code to handle the error appropriately. abort() causes the application to generate a crash log and terminate. You should not use this function in a shipping application, although it may be useful during development. If it is not possible to recover from the error, display an alert panel that instructs the user to quit the application by pressing the Home button. */ NSLog(@"Unresolved error %@, %@", error, [error userInfo]); abort(); } } } - (BOOL)tableView:(UITableView *)tableView canMoveRowAtIndexPath:(NSIndexPath *)indexPath { // The table view should not be re-orderable. return NO; } #pragma mark - #pragma mark Table view delegate - (void)tableView:(UITableView *)aTableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath { // Set the detail item in the detail view controller. NSManagedObject *selectedObject = [self.fetchedResultsController objectAtIndexPath:indexPath]; self.detailViewController.detailItem = selectedObject; } #pragma mark - #pragma mark Fetched results controller - (NSFetchedResultsController *)fetchedResultsController { if (fetchedResultsController != nil) { return fetchedResultsController; } /* Set up the fetched results controller. */ // Create the fetch request for the entity. NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init]; // Edit the entity name as appropriate. NSEntityDescription *entity = [NSEntityDescription entityForName:@"Details" inManagedObjectContext:managedObjectContext]; [fetchRequest setEntity:entity]; // Set the batch size to a suitable number. [fetchRequest setFetchBatchSize:20]; // Edit the sort key as appropriate. NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"EmployeeName" ascending:NO]; NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil]; [fetchRequest setSortDescriptors:sortDescriptors]; // Edit the section name key path and cache name if appropriate. // nil for section name key path means "no sections". NSFetchedResultsController *aFetchedResultsController = [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest managedObjectContext:managedObjectContext sectionNameKeyPath:nil cacheName:@"Root"]; aFetchedResultsController.delegate = self; self.fetchedResultsController = aFetchedResultsController; [aFetchedResultsController release]; [fetchRequest release]; [sortDescriptor release]; [sortDescriptors release]; return fetchedResultsController; } #pragma mark - #pragma mark Fetched results controller delegate - (void)controllerWillChangeContent:(NSFetchedResultsController *)controller { [self.tableView beginUpdates]; } - (void)controller:(NSFetchedResultsController *)controller didChangeSection:(id <NSFetchedResultsSectionInfo>)sectionInfo atIndex:(NSUInteger)sectionIndex forChangeType:(NSFetchedResultsChangeType)type { switch(type) { case NSFetchedResultsChangeInsert: [self.tableView insertSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeDelete: [self.tableView deleteSections:[NSIndexSet indexSetWithIndex:sectionIndex] withRowAnimation:UITableViewRowAnimationFade]; break; } } - (void)controller:(NSFetchedResultsController *)controller didChangeObject:(id)anObject atIndexPath:(NSIndexPath *)indexPath forChangeType:(NSFetchedResultsChangeType)type newIndexPath:(NSIndexPath *)newIndexPath { UITableView *tableView = self.tableView; switch(type) { case NSFetchedResultsChangeInsert: [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeDelete: [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; break; case NSFetchedResultsChangeUpdate: [self configureCell:[tableView cellForRowAtIndexPath:indexPath] atIndexPath:indexPath]; break; case NSFetchedResultsChangeMove: [tableView deleteRowsAtIndexPaths:[NSArray arrayWithObject:indexPath] withRowAnimation:UITableViewRowAnimationFade]; [tableView insertRowsAtIndexPaths:[NSArray arrayWithObject:newIndexPath]withRowAnimation:UITableViewRowAnimationFade]; break; } } - (void)controllerDidChangeContent:(NSFetchedResultsController *)controller { [self.tableView endUpdates]; } #pragma mark - #pragma mark Memory management - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Relinquish ownership any cached data, images, etc. that aren't in use. } - (void)viewDidUnload { // Relinquish ownership of anything that can be recreated in viewDidLoad or on demand. // For example: self.myOutlet = nil; } - (void)dealloc { [detailViewController release]; [fetchedResultsController release]; [managedObjectContext release]; [super dealloc]; } @end // // AddViewController.m // EmployeeDetails // // Created by Dipanjan on 15/02/11. // Copyright 2011 __MyCompanyName__. All rights reserved. // #import "AddViewController.h" #import "EmployeeDetailsAppDelegate.h" #import "RootViewController.h" @implementation AddViewController @synthesize empName; @synthesize empID; @synthesize empDepartment; @synthesize backButton; // The designated initializer. Override if you create the controller programmatically and want to perform customization that is not appropriate for viewDidLoad. /* - (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil { self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil]; if (self) { // Custom initialization. } return self; } */ /* // Implement viewDidLoad to do additional setup after loading the view, typically from a nib. - (void)viewDidLoad { [super viewDidLoad]; } */ -(void)saveDetails{ EmployeeDetailsAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate]; NSManagedObjectContext *context = [appDelegate managedObjectContext]; NSManagedObject *newDetails; newDetails = [NSEntityDescription insertNewObjectForEntityForName:@"Details" inManagedObjectContext:context]; [newDetails setValue:empID.text forKey:@"EmployeeID"]; [newDetails setValue:empName.text forKey:@"EmployeeName"]; [newDetails setValue:empDepartment.text forKey:@"EmployeeDepartment"]; empID.text = @""; empName.text = @""; empDepartment.text = @""; NSLog(@"%@........----->>>...", newDetails); NSError *error; [context save:&error]; [self dismissModalViewControllerAnimated:YES]; } -(void)findDetails { EmployeeDetailsAppDelegate *appDelegate = [[UIApplication sharedApplication]delegate]; NSManagedObjectContext *context = [appDelegate managedObjectContext]; NSEntityDescription *entityDesc = [NSEntityDescription entityForName:@"Details" inManagedObjectContext:context]; NSFetchRequest *request = [[NSFetchRequest alloc]init]; [request setEntity:entityDesc]; NSPredicate *pred = [NSPredicate predicateWithFormat:@"(EmployeeName = %@)", empName.text]; [request setPredicate:pred]; NSManagedObject *matches = nil; NSError *error; NSArray *objects = [context executeFetchRequest:request error:&error]; if ([objects count] == 0) { } else { matches = [objects objectAtIndex:0]; empID.text = [matches valueForKey:@"EmployeeID"]; empDepartment.text = [matches valueForKey:@"EmployeeDepartment"]; } [request release]; [self dismissModalViewControllerAnimated:YES]; } - (BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation { // Overriden to allow any orientation. return YES; } - (void)didReceiveMemoryWarning { // Releases the view if it doesn't have a superview. [super didReceiveMemoryWarning]; // Release any cached data, images, etc. that aren't in use. } - (void)viewDidUnload { self.empName = nil; self.empID = nil; self.empDepartment = nil; [super viewDidUnload]; // Release any retained subviews of the main view. // e.g. self.myOutlet = nil; } - (void)dealloc { [empID release]; [empName release]; [empDepartment release]; [super dealloc]; } @end Please let me know the answer as soon as possible. Thank you. Regards, Dipanjan

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  • Capturing image with WDS is stuck on 'Capturing Windows Image Metadata'

    - by user74499
    Hello, I'm trying to capture a rather large (100gigs) windows xp partition to a WIM file on an attached USB hard drive. Under 'Task Progress' it's saying 'Capturing Windows image Metadata', which is where it has been for a while (like 1.5 hours) - the blue bar is at the end of the screen, i.e. 100% I can move the windows around the screen so I suspect that the operation hasn't crashed yet but does this part of the process take a long time? I have only ever captured a 3gig partition before. Thanks.

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  • rsync on QNAP NAS fails recently

    - by user192702
    I have been using rsync to copy a large backup file from a remote host to my QNAP NAS. It's been working fine until recently. It seems like almost every time when it executes it's giving a time out after 15s. Following is what I have captured in the log. Any ideas? 2013-11-10 23:10:01 HKT - Executing: rsync -t -v -e ssh [email protected]:/home/backup/backup/backup_file-11102013* /share/homes/backup/backup/web/database [receiver] io timeout after 10 seconds -- exiting rsync error: timeout in data send/receive (code 30) at io.c(140) [receiver=3.0.7] rsync: connection unexpectedly closed (73 bytes received so far) [generator] rsync error: error in rsync protocol data stream (code 12) at io.c(601) [generator=3.0.7] 2013-11-10 23:10:15 HKT - Done rsync

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  • DNS lookup failed --- dig: couldn't get address for 'ns1.p34.dynect.net': failure

    - by Udit Gupta
    I am a Network Admin from India, managing a large University Network of more than 15000 users. Here goes my problem - My DNS is unable to get ip address for ns1.p34.dynect.net. when i use dig +trace twitter.com on my DNS Server i get this messages:- dig: couldn't get address for 'ns1.p34.dynect.net': failure and this is happening with all those sites listed with dynect.net like twitter,linkedin,quora etc. Find the attached screen shot for the same message. Right now I have temporally fixed (not actually fixed) the problem using Google DNS (8.8.8.8) What could be the issue as It is able to resolve all other sites perfectlly. Thanks Edit: As suggested in answer, I am attaching one more screen shot.

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  • Dell Optiplex 980 vs. Dell Studio XPS 9000?

    - by Dave
    My company is allowing me to upgrade to either the XPS 9000 or the Optiplex 980. I haven't bought an Optiplex in over a decade, and the only thing I can remember is that the Optiplex is really meant for corporate IT environments, and we're not even close being large enough to have IT issues. I think the components might be of higher quality as well, like the motherboard and power supply. The XPS 9000 is about $150 cheaper than the Optiplex, but the Optiplex has 4GB more RAM, a 2nd video card, and an extra year of service. Seems like the Optiplex is a better deal overall, but since I haven't ever used one, I wanted to see what everyone else here thought.

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