Search Results

Search found 20211 results on 809 pages for 'language implementation'.

Page 656/809 | < Previous Page | 652 653 654 655 656 657 658 659 660 661 662 663  | Next Page >

• How to perform spatial partitioning in n-dimensions?

  - by kevin42

  I'm trying to design an implementation of Vector Quantization as a c++ template class that can handle different types and dimensions of vectors (e.g. 16 dimension vectors of bytes, or 4d vectors of doubles, etc). I've been reading up on the algorithms, and I understand most of it: here and here I want to implement the Linde-Buzo-Gray (LBG) Algorithm, but I'm having difficulty figuring out the general algorithm for partitioning the clusters. I think I need to define a plane (hyperplane?) that splits the vectors in a cluster so there is an equal number on each side of the plane. [edit to add more info] This is an iterative process, but I think I start by finding the centroid of all the vectors, then use that centroid to define the splitting plane, get the centroid of each of the sides of the plane, continuing until I have the number of clusters needed for the VQ algorithm (iterating to optimize for less distortion along the way). The animation in the first link above shows it nicely. My questions are: What is an algorithm to find the plane once I have the centroid? How can I test a vector to see if it is on either side of that plane?

  Read the article

• Help needed in grokking password hashes and salts

  - by javafueled

  I've read a number of SO questions on this topic, but grokking the applied practice of storing a salted hash of a password eludes me. Let's start with some ground rules: a password, "foobar12" (we are not discussing the strength of the password). a language, Java 1.6 for this discussion a database, postgreSQL, MySQL, SQL Server, Oracle Several options are available to storing the password, but I want to think about one (1): Store the password hashed with random salt in the DB, one column Found on SO and elsewhere is the automatic fail of plaintext, MD5/SHA1, and dual-columns. The latter have pros and cons MD5/SHA1 is simple. MessageDigest in Java provides MD5, SHA1 (through SHA512 in modern implementations, certainly 1.6). Additionally, most RDBMSs listed provide methods for MD5 encryption functions on inserts, updates, etc. The problems become evident once one groks "rainbow tables" and MD5 collisions (and I've grokked these concepts). Dual-column solutions rest on the idea that the salt does not need to be secret (grok it). However, a second column introduces a complexity that might not be a luxury if you have a legacy system with one (1) column for the password and the cost of updating the table and the code could be too high. But it is storing the password hashed with a random salt in single DB column that I need to understand better, with practical application. I like this solution for a couple of reasons: a salt is expected and considers legacy boundaries. Here's where I get lost: if the salt is random and hashed with the password, how can the system ever match the password? I have theory on this, and as I type I might be grokking the concept: Given a random salt of 128 bytes and a password of 8 bytes ('foobar12'), it could be programmatically possible to remove the part of the hash that was the salt, by hashing a random 128 byte salt and getting the substring of the original hash that is the hashed password. Then re hashing to match using the hash algorithm...??? So... any takers on helping. :) Am I close?

  Read the article

• What's the Matlab equivalent of NULL, when it's calling COM/ActiveX methods?

  - by David M

  Hi, I maintain a program which can be automated via COM. Generally customers use VBS to do their scripting, but we have a couple of customers who use Matlab's ActiveX support and are having trouble calling COM object methods with a NULL parameter. They've asked how they do this in Matlab - and I've been scouring Mathworks' COM/ActiveX documentation for a day or so now and can't figure it out. Their example code might look something like this: function do_something() OurAppInstance = actxserver('Foo.Application'); OurAppInstance.Method('Hello', NULL) end where NULL is where in another language, we'd write NULL or nil or Nothing, or, of course, pass in an object. The problem is this is optional (and these are implemented as optional parameters in most, but not all, cases) - these methods expect to get NULL quite often. They tell me they've tried [] (which from my reading seemed the most likely) as well as '', Nothing, 'Nothing', None, Null, and 0. I have no idea how many of those are even valid Matlab keywords - certainly none work in this case. Can anyone help? What's Matlab's syntax for a null pointer / object for use as a COM method parameter? Update: Thanks for all the replies so far! Unfortunately, none of the answers seem to work, not even libpointer. The error is the same in all cases: Error: Type mismatch, argument 2 This parameter in the COM type library is described in RIDL as: HRESULT _stdcall OurMethod([in] BSTR strParamOne, [in, optional] OurCoClass* oParamTwo, [out, retval] VARIANT_BOOL* bResult); The coclass in question implements a single interface descending from IDispatch.

  Read the article

• Persistent warning message about "initWithDelegate"!

  - by RickiG

  Hi This is not an actual Xcode error message, it is a warning that has been haunting me for a long time. I have found no way of removing it and I think I maybe have overstepped some unwritten naming convention rule. If I build a class, most often extending NSObject, whose only purpose is to do some task and report back when it has data, I often give it a convenience constructor like "initWithDelegate". The first time I did this in my current project was for a class called ISWebservice which has a protocol like this: @protocol ISWebserviceDelegate @optional - (void) serviceFailed:(NSError*) error; - (void) serviceSuccess:(NSArray*) data; @required @end Declared in my ISWebservice.h interface, right below my import statements. I have other classes that uses a convenience constructor named "initWithDelegate". E.g. "InternetConnectionLost.h", this class does not however have its methods as optional, there are no @optional @required tags in the declaration, i.e. they are all required. Now my warning pops up every time I instantiate one of these Classes with convenience constructors written later than the ISWebservice, so when utilizing the "InternetConnectionLost" class, even though the entire Class owning the "InternetConnectionLost" object has nothing to do with the "ISWebservice" Class, no imports, methods being called, no nothing, the warning goes: 'ClassOwningInternetConnectionLost' does not implement the 'ISWebserviceDelegate' protocol I does not break anything, crash at runtime or do me any harm, but it has begun to bug me as I near release. Also, because several classes use the "initWithDelegate" constructor naming, I have 18 of these warnings in my build results and I am getting uncertain if I did something wrong, being fairly new at this language. Hope someone can shed a little light on this warning, thank you:)

  Read the article

• A map and set which uses contiguous memory and has a reserve function

  - by edA-qa mort-ora-y

  I use several maps and sets. The lack of contiguous memory, and high number of (de)allocations, is a performance bottleneck. I need a mainly STL-compatbile map and set class which can use a contiguous block of memory for internal objects (or multiple blocks). It also needs to have a reserve function so that I can preallocate for expected sizes. Before I write my own I'd like to check what is available first. Is there something in Boost which does this? Does somebody know of an available implementation elsewhere? Intrusive collection types are not usable here as the same objects need to exist in several collections. As far as I know STL memory pools are per-type, not per instance. These global pools are not efficient with respect to memory locality in mutli-cpu/core processing. Object pools don't work as the types will be shared between instance but their pool should not. In many cases a hash map may be an option in some cases.

  Read the article

• With PascalMock how do I mock a method with an untyped out parameter and an open array parameter?

  - by Oliver Giesen

  I'm currently in the process of getting started with unit testing and mocking for good and I stumbled over the following method that I can't seem to fabricate a working mock implementation for: function GetInstance(const AIID: TGUID; out AInstance; const AArgs: array of const; const AContextID: TImplContextID = CID_DEFAULT): Boolean; (TImplContextID is just an alias for Integer) I thought it would have to look something like this: function TImplementationProviderMock.GetInstance( const AIID: TGUID; out AInstance; const AArgs: array of const; const AContextID: TImplContextID): Boolean; begin Result := AddCall('GetInstance') .WithParams([@AIID, AContextID]) .ReturnsOutParams([AInstance]) .ReturnValue; end; But the compiler complains about the .ReturnsOutParams([AInstance]) saying "Bad argument type in variable type array constructor.". Also I haven't found a way to specify the open array parameter AArgs at all. Also, is using the @-notation for the TGUID-typed parameter the right way to go? Is it possible to mock this method with the current version of PascalMock at all?

  Read the article

• Nested factory methods in Objective-C

  - by StephenT

  What's the best way to handle memory management with nested factory methods, such as in the following example? @implementation MyClass + (MyClass *) SpecialCase1 { return [MyClass myClassWithArg:1]; } + (MyClass *) SpecialCase2 { return [MyClass myClassWithArg:2]; } + (MyClass *) myClassWithArg:(int)arg { MyClass *instance = [[[MyClass alloc] initWithArg:arg] autorelease]; return instance; } - (id) initWithArg:(int)arg { self = [super init]; if (nil != self) { self.arg = arg; } return self; } @end The problem here (I think) is that the autorelease pool is flushed before the SpecialCaseN methods return to their callers. Hence, the ultimate caller of SpecialCaseN can't rely on the result having been retained. (I get "[MyClass copyWithZone:]: unrecognized selector sent to instance 0x100110250" on trying to assign the result of [MyClass SpecialCase1] to a property on another object.) The reason for wanting the SpecialCaseN factory methods is that in my actual project, there are multiple parameters required to initialize the instance and I have a pre-defined list of "model" instances that I'd like to be able to create easily. I'm sure there's a better approach than this.

  Read the article

• Problem consuming Exchange Web Service 2010 with jax-ws metro

  - by Johan Karlberg

  I am trying to consume the Exchange 2010 Web Service interface using JAX-WS. I'm using JAX-WS 2.2 RI (Metro 2.0). 2.1 exhibited the same problem. I am running into trouble with Exchange, which returns "HTTP/1.1 415 Cannot process the message because the content type 'text/xml;charset=utf-8' was not the expected type 'text/xml; charset=utf-8'." as a reponse (2.1 quoted the charset value, otherwise same response). Apparently I need to dictate the exact Content-type header for Exchange to be happy. Is there a way for me to do this without forcing me to manually rebuild the dependency? I currently rely on published maven artifacts, and would like to continue doing this if at all possible. The consuming process is a regular J2SE app, with no containers in sight. I have control of the application and can add pretty much anything required to the applications scope, but can not add out-of-process items like proxy servers. The client classes were generated from local WSDL, but the charset specification is derived from constants declared in the jaxws RI implementation, not the generated code. The resulting HTTP transport is thus handled by the standard http/https client from Sun JRE5 or JRE6.

  Read the article

• Teach Markup or use a WYSIWYG editor?

  - by Atomiton

  When it comes to WYSIWYG editors WYSI rarely WYG. The problem I always have is when people paste in formatted text from word. Ideally, what I'm looking for is a way for people to input text into the document while at the same time teaching them structure... I just don't know if that's a realistic goal ( compared to cut n' paste ) I'm curious if people have found using something other than WYSIWYG editors ( take SO, for example ) has worked for REAL WORLD USERS. I'm not talking about programmers, developers and experience internet users... I'm talking about your average user. I'd be interested in best practices when it comes to getting users to enter content... and I'd love it if someone could point me to some good editors/examples. there are lots of choices when it comes to WYSIWYG ( ckEditor, FreeTextBox, TinyMCE ) but I don't hear a lot about SO-like techniques. Does adding that small barrier scares users away? Is it too difficult to teach people to mark up their text? Is it easier to teach them html? Is a BBCode implementation a good idea? What are some Pros/Cons to wysiwyg/markup. What approach have others used?

  Read the article

• Python template engine

  - by jturo

  Hello there, Could it be possible if somebody could help me get started in writing a python template engine? I'm new to python and as I learn the language I've managed to write a little MVC framework running in its own light-weight-WSGI-like server. I've managed to write a script that finds and replaces keys for values: (Obviously this is not how my script is structured or implemented. this is just an example) from string import Template html = '<html>\n' html += ' <head>\n' html += ' <title>This is so Cool : In Controller HTML</title>\n' html += ' </head>\n' html += ' <body>\n' html += ' Home | <a href="/hi">Hi ${name}</a>\n' html += ' </body>\n' html += '<html>' Template(html).safe_substitute(dict(name = 'Arturo')) My next goal is to implement custom statements, modifiers, functions, etc (like 'for' loop) but i don't really know if i should use another module that i don't know about. I thought of regular expressions but i kind feel like that wouldn't be an efficient way of doing it Any help is appreciated, and i'm sure this will be of use to other people too. Thank you

  Read the article

• What are some choices to port existing Windows GUI app written in C to Linux?

  - by Warner Young

  I've been tasked with porting an existing Windows GUI app to Linux. Ideally, I'd like to do this so the same code base can be used to build either the Windows version or the Linux version. I'll be doing my work on Ubuntu 9.04. After searching around, it's unclear to me what tools are best suited to help me with this. A list of loose requirements would be: The code is in C, not C++, and should compile to build both Windows and Linux versions. Since it's existing code, and fairly large, converting to a managed language like .NET is out of the question for now. I would prefer if I can use the same dialogs in both systems. In Windows, putting up a dialog is pretty simple. You build the dialog in the Resource Editor in Visual Studio, then call DialogBox() API, and handle the event messages. I would really like to find something that can do the equivalent on the Linux side. It would also be nice to have a good IDE similar to Visual Studio. Any helps or hints would be appreciated. Thanks,

  Read the article

• Java - Custom PropertyEditorSupport to display units

  - by I82Much

  All, I'm trying to make the properties of my node have Units associated with the measure. ( I am using the JScience.org implementation of JSR 275) So for instance, public class Robot extends AbstractNode { // in kg float vehicleMass; @Override public Sheet createSheet() { Sheet s = Sheet.createDefault(); Sheet.Set set = s.createPropertiesSet(); try { PropertySupport.Reflection vehicleMassField = new PropertySupport.Reflection(this, float.class, "vehicleMass"); vehicleMassField.setValue("units", SI.KILOGRAMS); vehicleMassField.setName("vehicleMass"); set.put(vehicleMassField); PropertyEditorManager.registerEditor(float.class, UnitInPlaceEditor.class); } catch (NoSuchMethodException ex) { Exceptions.printStackTrace(ex); } s.put(set); return s; } } I want my UnitInPlaceEditor to append the units to the end of the string representation of the number, and when the field is clicked (enters edit mode) for the units to disappear and just the number becomes selected for editing. I can make the units appear, but I cannot get the units to disappear when the field enters editing mode. public class UnitsInplaceEditor extends PropertyEditorSupport implements ExPropertyEditor { private PropertyEnv pe; @Override public String getAsText() { // Append the unit by retrieving the stored value } @Override public void setAsText(String s) { // strip off the unit, parse out the number } public void attachEnv(PropertyEnv pe) { this.pe = pe; } } Here's a screenshot of the display - I like it like this.. but here's the value being edited; note the unit stays there. Basically I want one value (string) to be displayed in the field when the field is NOT being edited, and a different to be displayed when user starts editing the field. Barring that, I'd like to put a constant jlabel for the units (uneditable) to the right of the text field. Anyone know how to do this?

  Read the article

• When connecting SAP Business One to SQL Server 2005, what is the

  - by Nick

  we have SAP Business One - Fourth Shift Edition running here at a small manufacturing company. The consulting company that has come in to do the installation/implementation uses the "sa" id/pass to initially connect to the database to get the list of companies. From then on, I have to assume that its the sa id/pass that is being used to connect the client software to the database. Is this appropriate? I dont know where this data is being stored... as an ODBC connection? directly in the registry somewhere? Is it secure? Would it be better to set the users network ID in the database security and then use the "trusted connection" setting instead? Or do most people create a separate login in the database for each user and use that in the client settings? seems like the easiest way would be to add the users network login to the sql server security so they can use the "trusted connection"... but then wouldn't that allow ANY software to connect to the database from that machine? So anyways: what are the best-practices for setting this up?

  Read the article

• ANTLR Tree Grammar and StringTemplate Code Translation

  - by Behrooz Nobakht

  I am working on a code translation project with a sample ANTLR tree grammar as: start: ^(PROGRAM declaration+) -> program_decl_tmpl(); declaration: class_decl | interface_decl; class_decl: ^(CLASS ^(ID CLASS_IDENTIFIER)) -> class_decl_tmpl(cid={$CLASS_IDENTIFIER.text}); The group template file for it looks like: group My; program_decl_tmpl() ::= << *WHAT?* >> class_decl_tmpl(cid) ::= << public class <cid> {} >> Based on this, I have these questions: Everything works fine apart from that what I should express in WHAT? to say that a program is simply a list of class declarations to get the final generated output? Is this approach averagely suitable for not so a high-level language? I have also studied ANTLR Code Translation with String Templates, but it seems that this approach takes much advantage of interleaving code in tree grammar. Is it also possible to do it as much as possible just in String Templates?

  Read the article

• Parsing basic math equations for children's educational software?

  - by Simucal

  Inspired by a recent TED talk, I want to write a small piece of educational software. The researcher created little miniature computers in the shape of blocks called "Siftables". [David Merril, inventor - with Siftables in the background.] There were many applications he used the blocks in but my favorite was when each block was a number or basic operation symbol. You could then re-arrange the blocks of numbers or operation symbols in a line, and it would display an answer on another siftable block. So, I've decided I wanted to implemented a software version of "Math Siftables" on a limited scale as my final project for a CS course I'm taking. What is the generally accepted way for parsing and interpreting a string of math expressions, and if they are valid, perform the operation? Is this a case where I should implement a full parser/lexer? I would imagine interpreting basic math expressions would be a semi-common problem in computer science so I'm looking for the right way to approach this. For example, if my Math Siftable blocks where arranged like: [1] [+] [2] This would be a valid sequence and I would perform the necessary operation to arrive at "3". However, if the child were to drag several operation blocks together such as: [2] [\] [\] [5] It would obviously be invalid. Ultimately, I want to be able to parse and interpret any number of chains of operations with the blocks that the user can drag together. Can anyone explain to me or point me to resources for parsing basic math expressions? I'd prefer as much of a language agnostic answer as possible.

  Read the article

• Implement master detail in one datagrid in wpf

  - by Archie

  Hello, I have classes as following: public class Property { public string PropertyName { get; set; } public int SumSubPropertValue; private List<SubProperty> propertyList; public void CalculateSumSubPropertValue { // implementation} } public class SubProperty { public string SubPropertyName { get; set; } public int SubPropertyValue { get; set; } } I have grouped the rows in datagrid on PropertyName . When the user clicks on PropertyName expnader the columns should display SubPropertyName and SubPropertyValue. Also SumSubPropertValue should appear in front of PropertyName in the expander header. My Datagrid is bound to a CollectionViewSource as follows: CollectionViewSource view = new CollectionViewSource(); view.Source = infoList; view.GroupDescriptions.Add(new PropertyGroupDescription("PropertyName")); Where infoList is ObservableCollection<Property>. My datagrid colmns look like <my:DataGrid.Columns> <my:DataGridTextColumn Header="SubPropertyName" Binding="{Binding SubPropertName}" Width="*"/> <my:DataGridTextColumn Header="SubPropertyValue" Binding="{Binding SubPropertyValue}" Width="*"/> </my:DataGrid.Columns> Can someone help me with it?

  Read the article

• Accessing type members outside the class in Scala

  - by Pekka Mattila

  Hi, I am trying to understand type members in Scala. I wrote a simple example that tries to explain my question. First, I created two classes for types: class BaseclassForTypes class OwnType extends BaseclassForTypes Then, I defined an abstract type member in trait and then defined the type member in a concerete class: trait ScalaTypesTest { type T <: BaseclassForTypes def returnType: T } class ScalaTypesTestImpl extends ScalaTypesTest { type T = OwnType override def returnType: T = { new T } } Then, I want to access the type member (yes, the type is not needed here, but this explains my question). Both examples work. Solution 1. Declaring the type, but the problem here is that it does not use the type member and the type information is duplicated (caller and callee). val typeTest = new ScalaTypesTestImpl val typeObject:OwnType = typeTest.returnType // declare the type second time here true must beTrue Solution 2. Initializing the class and using the type through the object. I don't like this, since the class needs to be initialized val typeTest = new ScalaTypesTestImpl val typeObject:typeTest.T = typeTest.returnType // through an instance true must beTrue So, is there a better way of doing this or are type members meant to be used only with the internal implementation of a class?

  Read the article

• Join + IEqualityComparer<T> and HashCode

  - by Jesus Rodriguez

  Im writing my own LINQ reference but Im getting troubles with some of the more complicated operators implementations. There is a Join implementation that takes a IEqualityComparer Im getting just crazy. Im trying to understand it first before I write (obviously) Image this two lists: List<string> initials = new List<string> {"A", "B", "C", "D", "E"}; List<string> words = new List<string> {"Ant", "Crawl", "Pig", "Boat", "Elephant", "Arc"}; Nothing weird here. I want to join both lists by the Initial, something like: Initial=A Word=Ant Initial=A Word=Arc Initial=B Word=Boat ... I need a comparator, I wrote this: public class InitialComparator : IEqualityComparer<string> { public bool Equals(string x, string y) { return x.StartsWith(y); } public int GetHashCode(string obj) { return obj[0].GetHashCode(); } } The Join itself: var blah = initials.Join(words, initial => initial, word => word, (initial, word) => new {Initial = initial, Word = word}, new InitialComparator()); It's the first time Im using HashCodes, after a good session of debugging I see that every word go to the comparator and look at its HashCode, if another word has the same HashCode it calls equals. Since I want to compare just the initial I though that I just need the first letter Hash (Am I wrong?) The thing is that this is not working correctly. Its says that "Ant" and "Arc" are equals, Ok, its comparing every word in the same list or not, But it adds only the last word it finds, in this case Arc, ignoring Ant and Ant is equals to "A" too... If I put "Ant" and "Ant" it add both. In short, What is the way of doing something like that? I know that Im doing something wrong. Thank you.

  Read the article

• Umlaute from JSP-page are misinterpreted

  - by Karin

  I'm getting Input from a JSP page, that can contain Umlaute. (e.g. Ä,Ö,Ü,ä,ö,ü,ß). Whenever an Umlaut is entered in the Input field an incorrect value gets passed on. e.g. If an "ä" (UTF-8:U+00E4) gets entered in the input field, the String that is extracted from the argument is "ä" (UTF-8: U+00C3 and U+00A4) It seems to me as if the UTF-8 hex encoding (which is c3 a4 for an "ä") gets used for the conversion. How can I retrieved the correct value? Here are snippets from the current implementation The JSP-page passes the input value "pk" on to the processing logic: <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> ... <input type="text" name="<%=pk.toString()%>" value="<%=value%>" size="70"/> <button type="submit" title="Edit" value='Save' onclick="action.value='doSave';pk.value='<%=pk.toString()%>'"><img src="icons/run.png"/>Save</button> The value gets retrieved from args and converted to a string: UUID pk = UUID.fromString(args.get("pk")); //$NON-NLS-1$ String value = args.get(pk.toString()); Note: Umlaute that are saved in the Database get displayed correctly on the page.

  Read the article

• How to use <c:out value=...> taglib

  - by artaxerxe

  I have the class A: package a; public class A { private int x = 9; public int getX() { return x; } } and the ajsp.jsp file: <%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib prefix="c" uri="http://java.sun.com/jstl/core" %> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body> <jsp:useBean id = "a" class = "a.A" /> <c:out value = "${a.x}" /> </body> </html> when i run it, it gives an error : org.apache.jasper.JasperException: /ajsp.jsp(11,0) PWC6236: According to TLD or attribute directive in tag file, attribute value does not accept any expressions if instead of <c:out value = "${a.x}" /> i use <jsp:getProperty property="x" name="a"/> it goes perfect. So, what is the problem? Thank advance.

  Read the article

• Getting started with massive data

  - by Max

  I'm a math guy and occasionally do some statistics/machine learning analysis consulting projects on the side. The data I have access to are usually on the smaller side, at most a couple hundred of megabytes (and almost always far less), but I want to learn more about handling and analyzing data on the gigabyte/terabyte scale. What do I need to know and what are some good resources to learn from? Hadoop/MapReduce is one obvious start. Is there a particular programming language I should pick up? (I primarily work now in Python, Ruby, R, and occasionally Java, but it seems like C and Clojure are often used for large-scale data analysis?) I'm not really familiar with the whole NoSQL movement, except that it's associated with big data. What's a good place to learn about it, and is there a particular implementation (Cassandra, CouchDB, etc.) I should get familiar with? Where can I learn about applying machine learning algorithms to huge amounts of data? My math background is mostly on the theory side, definitely not on the numerical or approximation side, and I'm guessing most of the standard ML algorithms don't really scale. Any other suggestions on things to learn would be great!

  Read the article

• Generic object to object mapping with parametrized constructor

  - by Rody van Sambeek

  I have a data access layer which returns an IDataRecord. I have a WCF service that serves DataContracts (dto's). These DataContracts are initiated by a parametrized constructor containing the IDataRecord as follows: [DataContract] public class DataContractItem { [DataMember] public int ID; [DataMember] public string Title; public DataContractItem(IDataRecord record) { this.ID = Convert.ToInt32(record["ID"]); this.Title = record["title"].ToString(); } } Unfortanately I can't change the DAL, so I'm obliged to work with the IDataRecord as input. But in generat this works very well. The mappings are pretty simple most of the time, sometimes they are a bit more complex, but no rocket science. However, now I'd like to be able to use generics to instantiate the different DataContracts to simplify the WCF service methods. I want to be able to do something like: public T DoSomething<T>(IDataRecord record) { ... return new T(record); } So I'd tried to following solutions: Use a generic typed interface with a constructor. doesn't work: ofcourse we can't define a constructor in an interface Use a static method to instantiate the DataContract and create a typed interface containing this static method. doesn't work: ofcourse we can't define a static method in an interface Use a generic typed interface containing the new() constraint doesn't work: new() constraint cannot contain a parameter (the IDataRecord) Using a factory object to perform the mapping based on the DataContract Type. does work, but: not very clean, because I now have a switch statement with all mappings in one file. I can't find a real clean solution for this. Can somebody shed a light on this for me? The project is too small for any complex mapping techniques and too large for a "switch-based" factory implementation.

  Read the article

• Which articles I've should read before starting to make my custom drawn winforms app?

  - by Dmitriy Matveev

  Hello! I'm currently developing a windows forms application with a lot of user controls. Some of them are just custom drawn buttons or panels and some of them are a compositions of these buttons and panels inside of FlowLayoutPanels and TableLayoutPanels. And the window itself is also custom drawn. I don't have much experience in winforms development, but I've made a proper decomposition of proposed design into user controls and implementation is already almost finished. I've already solved many arisen problems during development by the help of the google, msdn, SO and several dirty hacks (when nothing were helping) and still experiencing some of them. There are a lot of gaps in my knowledge base, since I don't know answers to many questions like: When I should use things like double buffer, suspended layout, suspended redraw ? What should I do with the controls which shouldn't be visible at some moment ? Common performance pitfalls (I think I've fallen in in several ones) ? So I think there should be some great articles which can give some knowledge enough to avoid most common problems and improve performance and maintainability of my application. Maybe some of you can recommend a few?

  Read the article

• Going from small to medium sized websites.

  - by Landitus

  I've been coding websites for a couple of years now, mostly in php and xhtml. I come from the design world, but I'm proud of doing standart compliant websites and great interfaces. Also used Wordpress and loved it. Most of the time there were really simple commercial websites, with no database included, where everything is done from scratch. Every page is parsed through an index?page=xxx and But I have a few prospects that are larger websites (let's call them 'medium sized websites') where I feel I'm lacking the following: How to dispach or render the pages (MVC controller instead of index?page=???) Proper page hierarchy and easy breadcrumbs implementation Auto generation of navigation menu, or an easy way to maintain them? Clean URLs Form validation Easy database support I really don't know if I should be looking into php scripts, and refine my skills or get into a CMS (like drupal) or a PHP framework. I found Wordpress very assuring and didn't feel trapped into crazy conventions, but I feel is not the right tool for this. I hate the CMS Page with the big textbox as I am used to code every page by hand my pages are not a title and a textbox. Got the feeling? My php skills are sort of medium/low still, but I would like to hear some thoughts of what I should learn to take the next step!

  Read the article

• Generic unit test scheduling

  - by Raphink

  Hello, I'm (re)writing a program that does generic unit test scheduling. The current program is a mono-threaded Perl program, but I'm willing to modularize it and parallelize the tests. I'm also considering rewriting it in Python. Here is what I need to do: I have a list of tests, with the following attributes: uri: a URI to test (could be HTTP/HTTPS/SSH/local) ; depends: an associative array of tests/values that this test depends on ; join: a list of DB joints to be added when selecting items to process in this test ; depends_db: additional conditions to add to the DB request when selecting items to process in this test. The program builds a dependency tree, beginning with the tests that have no dependencies ; for each test: a list of items is selected from the database using the conditions (results of depending tests, joints and depends_db) ; the list of items is sent to the URI (using POST or stdin) ; the result is retrived as a YAML file listing the state and comments for the test for each tested item ; the results are stored in the DB ; the test returns, allowing depending tests to be performed. the program generates reports (CSV, DB, graphviz) of the performed tests. The primary use of this program currently is to test a fleet of machines against services such as backup, DNS, etc. The tests can then be: - backup: hosted on the backup machine(s), called through HTTP, checks if the machines' backup went well ; - DNS: hosted on the local machine, called via stdin, checks if the machines' fqdn have a valid DNS entry. Does such a tool/module already exist? What would be the best implementation to achieve this (using Perl or Python)?

  Read the article

< Previous Page | 652 653 654 655 656 657 658 659 660 661 662 663  | Next Page >