Search Results

Search found 13710 results on 549 pages for 'partial methods'.

Page 185/549 | < Previous Page | 181 182 183 184 185 186 187 188 189 190 191 192  | Next Page >

• how do I best create a set of list classes to match my business objects

  - by ken-forslund

  I'm a bit fuzzy on the best way to solve the problem of needing a list for each of my business objects that implements some overridden functions. Here's the setup: I have a baseObject that sets up database, and has its proper Dispose() method All my other business objects inherit from it, and if necessary, override Dispose() Some of these classes also contain arrays (lists) of other objects. So I create a class that holds a List of these. I'm aware I could just use the generic List, but that doesn't let me add extra features like Dispose() so it will loop through and clean up. So if I had objects called User, Project and Schedule, I would create UserList, ProjectList, ScheduleList. In the past, I have simply had these inherit from List< with the appropriate class named and then written the pile of common functions I wanted it to have, like Dispose(). this meant I would verify by hand, that each of these List classes had the same set of methods. Some of these classes had pretty simple versions of these methods that could have been inherited from a base list class. I could write an interface, to force me to ensure that each of my List classes has the same functions, but interfaces don't let me write common base functions that SOME of the lists might override. I had tried to write a baseObjectList that inherited from List, and then make my other Lists inherit from that, but there are issues with that (which is really why I came here). One of which was trying to use the Find() method with a predicate. I've simplified the problem down to just a discussion of Dispose() method on the list that loops through and disposes its contents, but in reality, I have several other common functions that I want all my lists to have. What's the best practice to solve this organizational matter?

  Read the article

• How can I refactor this to work without breaking the pattern horribly?

  - by SnOrfus

  I've got a base class object that is used for filtering. It's a template method object that looks something like this. public class Filter { public void Process(User u, GeoRegion r, int countNeeded) { List<account> selected = this.Select(u, r, countNeeded); // 1 List<account> filtered = this.Filter(selected, u, r, countNeeded); // 2 if (filtered.Count > 0) { /* do businessy stuff */ } // 3 if (filtered.Count < countNeeded) this.SendToSuccessor(u, r, countNeeded - filtered) // 4 } } Select(...), Filter(...) are protected abstract methods and implemented by the derived classes. Select(...) finds objects in the based on x criteria, Filter(...) filters those selected further. If the remaining filtered collection has more than 1 object in it, we do some business stuff with it (unimportant to the problem here). SendToSuccessor(...) is called if there weren't enough objects found after filtering (it's a composite where the next class in succession will also be derived from Filter but have different filtering criteria) All has been ok, but now I'm building another set of filters, which I was going to subclass from this. The filters I'm building however would require different params and I don't want to just implement those methods and not use the params or just add to the param list the ones I need and have them not used in the existing filters. They still perform the same logical process though. I also don't want to complicated the consumer code for this (which looks like this) Filter f = new Filter1(); Filter f2 = new Filter2(); Filter f3 = new Filter3(); f.Sucessor = f2; f2.Sucessor = f3; /* and so on adding filters as successors to previous ones */ foreach (User u in users) { foreach (GeoRegion r in regions) { f.Process(u, r, ##); } } How should I go about it?

  Read the article

• Importing data from third party datasource (open architecture design )

  - by mare

  How would you design an application (classes, interfaces in class library) in .NET when we have a fixed database design on our side and we need to support imports of data from third party data sources, which will most likely be in XML? For instance, let us say we have a Products table in our DB which has columns Id Title Description TaxLevel Price and on the other side we have for instance Products: ProductId ProdTitle Text BasicPrice Quantity. Currently I do it like this: Have the third party XML convert to classes and XSD's and then deserialize its contents into strong typed objects (what we get as a result of this process is classes like ThirdPartyProduct, ThirdPartyClassification, etc.). Then I have methods like this: InsertProduct(ThirdPartyProduct newproduct) I do not use interfaces at the moment but I would like them to. What I would like is implement something like public class Contoso_ProductSynchronization : ProductSynchronization InsertProduct(ContosoProduct p) where ProductSynchronization will be an interface or abstract class. There will most likely be many implementations of ProductSynchronization. I cannot hardcode the types - classes like ContosoProduct, NorthwindProduct might be created from the third party XML's (so preferably I would continue to use deserialization). Hopefully someone will understand what I'm trying to explain here. Just imagine you are the seller and you have numerous providers and each one uses their own proprietary XML format. I don't mind the development, which will of course be needed everytime new format appears, because it will only require 10-20 methods to be implemented, I just want the architecture to be open and support that.

  Read the article

• Load page for validation but do not display it to user in ASP.NET

  - by Kevin

  We have a site requiring users pay $2 to view the details of a record. We occasionally get complaints because we send them to the payment page, and once they pay it turns out the record isn't valid, or it was lost, or the data couldn't be generated. So we want to add in a check to ensure the page constructs properly before the user is required to pay for it. However, we don't want the user to have access to the page until they pay for it. Is there anything in ASP.NET 3.5 or just general web design that would allow something like this? The data on the record is real time and computed on a backend server before sent to the client. Occasionally this computation fails for whatever reason. Our alternative is to call all of the loading methods and validate the data, then redirect them to the payment page. The problem is A) this will be a relatively involved process rewriting all of these methods to return validation information, and B) it still doesn't guarentee us the page will load properly. Any thoughts?

  Read the article

• C# wrapper for objects

  - by Haggai

  I'm looking for a way to create a generic wrapper for any object. The wrapper object will behave just like the class it wraps, but will be able to have more properties, variable, methods etc., for e.g. object counting, caching etc. Say the wrapper class be called Wrapper, and the class to be wrapped be called Square and has the constructor Square(double edge_len) and the properties/methods EdgeLength and Area, I would like to use it as follows: Wrapper<Square> mySquare = new Wrapper<Square>(2.5); /* or */ new Square(2.5); Console.Write("Edge {0} -> Area {1}", mySquare.EdgeLength, mySquare.Area); Obviously I can create such a wrapper class for each class I want to wrap, but I'm looking for a general solution, i.e. Wrapper<T> which can handle both primitive and compound types (although in my current situation I would be happy with just wrapping my own classes). Suggestions? Thanks.

  Read the article

• Unit Testing the Use of TransactionScope

  - by Randolpho

  The preamble: I have designed a strongly interfaced and fully mockable data layer class that expects the business layer to create a TransactionScope when multiple calls should be included in a single transaction. The problem: I would like to unit test that my business layer makes use of a TransactionScope object when I expect it to. Unfortunately, the standard pattern for using TransactionScope is a follows: using(var scope = new TransactionScope()) { // transactional methods datalayer.InsertFoo(); datalayer.InsertBar(); scope.Complete(); } While this is a really great pattern in terms of usability for the programmer, testing that it's done seems... unpossible to me. I cannot detect that a transient object has been instantiated, let alone mock it to determine that a method was called on it. Yet my goal for coverage implies that I must. The Question: How can I go about building unit tests that ensure TransactionScope is used appropriately according to the standard pattern? Final Thoughts: I've considered a solution that would certainly provide the coverage I need, but have rejected it as overly complex and not conforming to the standard TransactionScope pattern. It involves adding a CreateTransactionScope method on my data layer object that returns an instance of TransactionScope. But because TransactionScope contains constructor logic and non-virtual methods and is therefore difficult if not impossible to mock, CreateTransactionScope would return an instance of DataLayerTransactionScope which would be a mockable facade into TransactionScope. While this might do the job it's complex and I would prefer to use the standard pattern. Is there a better way?

  Read the article

• How can I take advantage of IObservable/IObserver to get rid of my "god object"?

  - by Will

  In a system I'm currently working on, I have many components which are defined as interfaces and base classes. Each part of the system has some specific points where they interact with other parts of the system. For example, the data readying component readies some data which eventually needs to go to the data processing portion, the communications component needs to query different components for their status for relaying to the outside, etc. Currently, I glue these parts of the system together using a "god object", or an object with intimate knowledge of different parts of the system. It registers with events over here and shuttles the results to methods over there, creates a callback method here and returns the result of that method over there, and passes many requests through a multi-threaded queue for processing because it "knows" certain actions have to run on STA threads, etc. While its convenient, it concerns me that this one type knows so much about how everybody else in the system is designed. I'd much prefer a more generic hub that can be given instances which can expose events or methods or callbacks or that can consume these. I've been seeing more about the IObservable/IObserver features of the reactive framework and that are being rolled into .NET 4.0 (I believe). Can I leverage this pattern to help replace my "god object"? How should I go about doing this? Are there any resources for using this pattern for this specific purpose?

  Read the article

• Updating database row from model

  - by Jamie Dixon

  Hey everyone, I'm haing a few problems updating a row in my database using Linq2Sql. Inside of my model I have two methods for updating and saving from my controller, which in turn receives an updated model from my view. My model methods like like: public void Update(Activity activity) { _db.Activities.InsertOnSubmit(activity); } public void Save() { _db.SubmitChanges(); } and the code in my Controller likes like: [HttpPost] public ActionResult Edit(Activity activity) { if (ModelState.IsValid) { UpdateModel<Activity>(activity); _activitiesModel.Update(activity); _activitiesModel.Save(); } return View(activity); } The problem I'm having is that this code inserts a new entry into the database, even though the model item i'm inserting-on-submit contains a primary key field. I've also tried re-attaching the model object back to the data source but this throws an error because the item already exists. Any pointers in the right direction will be greatly appreciated. UPDATE: I'm using dependancy injection to instantiate my datacontext object as follows: IMyDataContext _db; public ActivitiesModel(IMyDataContext db) { _db = db; }

  Read the article

• What is the best way to do scoped finds based on access control rules in Rails?

  - by Rafael Szuminski

  Hi I need to find an elegant solution to scoped finds based on access control rules. Essentially I have the following setup: Users Customers AccessControl - Defines which user has access to another users data Users need to be able to access not just their own customers but also shared customers of other users. Obviously something like a simple association will not work: has_many :customers and neither will this: has_many :customers, :conditions => 'user_id in (1,2,3,4,5)' because the association uses with_scope and the added condition is an AND condition not an OR condition. I also tried overriding the find and method_missing methods with the association extension like this: has_many :customers do def find(*args) #get the user_id and retrieve access conditions based on the id #do a find based on the access conditions and passed args end def method_missing(*args) #get the user_id and retrieve access conditions based on the id #do a find based on the access conditions and passed args end end but the issue is that I don't have access to the user object / parent object inside the extension methods and it just does not work as planned. I also tried default_scope but as posted here before you can't pass a block to a default scope. Anyhow, I know that data segmentation and data access controls have been done before using rails and am wondering if somebody found an elegant way to do it. UPDATE: The AccessControl table has the following layout user_id shared_user_id The customer table has this structure: id account_id user_id first_name last_name Assuming the the following data would be in the AccessControl table: 1 1 1 3 1 4 2 2 2 13 and so on... And the account_id for user 1 is 13 I need to be able to retrieve customers that can be best described with the following sql statement: select * from customers where (account_id = 13 and user_id = null) or (user_id in (1,3,4))

  Read the article

• XSLT special characters

  - by Apurv

  In the following XSL transformation how do I output the '<' and '' symbol? Input XML: <TestResult bugnumber="3214" testname="display.methods::close->test_ManyInvoke" errortype="Failure"><ErrorMessage><![CDATA[calling close() method failed - expected:<2>]]></ErrorMessage> XSLT: <xsl:template match="TestResult"> <xsl:variable name="errorMessage"> <xsl:value-of select="ErrorMessage" disable-output-escaping="yes"/> </xsl:variable> <Test name='{@testname}'> <TestResult> <Passed>false</Passed> <State>failure</State> <Metadata> <Entry name='bugnumber' value='{@bugnumber}' /> </Metadata> <TestOutput> <Metadata> <Entry name='ErrorMessage' value='{$errorMessage}' /> </Metadata> </TestOutput> </TestResult> </Test> </xsl:template> Output XML: <Test name="display.methods::close-&gttest_ManyInvoke"> <TestResult> <Passed>false</Passed> <State>failure</State> <Metadata> <Entry name="bugnumber" value="3214"/> </Metadata> <TestOutput> <Metadata> <Entry name="ErrorMessage" value="calling close() method failed - expected:&lt;2&gt;"/> </Metadata> </TestOutput> </TestResult> </Test>

  Read the article

• How to handle window closed in the middle of a long running operation gracefully?

  - by Marek

  We have the following method called directly from the UI thread: void DoLengthyProcessing() { DoStuff(); var items = DoMoreStuff(); //do even more stuff - 200 lines of code trimmed this.someControl.PrepareForBigThing(); //someControl is a big user control //additional 100 lines of code that access this.someControl this.someControl.Finish(items); } Many of the called methods call Application.DoEvents() (and they do so many times) (do not ask me why, this is black magic written by black magic programmers and it can not be changed because everyone is scared what the impact would be) and there is also an operation running on a background thread involved in the processing. As a result, the window is not fully nonresponsive and can be closed manually during the processing. The Dispose method of the form "releases" the someControl variable by setting it to null. As a result, in case the user closes the window during the lengthy process, a null reference exception is thrown. How to handle this gracefully without just catching and logging the exception caused by disposal? Assigning the someControl instance to a temporary variable in the beginning of the method - but the control contains many subcontrols with similar disposal scheme - sets them to null and this causes null reference exceptions in other place put if (this.IsDisposed) return; calls before every access of the someControl variable. - making the already nasty long method even longer and unreadable. in Closing event, just indicate that we should close and only hide the window. Dispose it at the end of the lengthy operation. This is not very viable because there are many other methods involved (think 20K LOC for a single control) that would need to handle this mechanism as well. How to most effectively handle window disposal (by user action) in the middle of this kind of processing?

  Read the article

• Analyzing an IronPython Scope

  - by Vercinegetorix

  I'm trying to write C# code with an embedded IronPython script. Then want to analyze the contents of the script, i.e. list all variables, functions, class and their members/methods. There's an easy way to start, assuming I've got a scope defined and code executed in it already: dynamic variables=pyScope.GetVariables(); foreach (string v in variables) { dynamic dynamicV=pyScope.GetVariable(); /*seems to return everything. variables, functions, classes, instances of classes*/ } But how do I figure out what the type of a variable is? For the following python 'objects', dynamicV.GetType() will return different values: x=5 --system.Int32 y="asdf" --system.String def func():... --IronPython.Runtime.PythonFunction z=class() -- IronPython.Runtime.Types.OldInstance, how can I identify what the actual python class is? class NewClass -- throws an error, GetType() is unavailable. This is almost what I'm looking for. I could capture the exception thrown when unavailable and assume it's a class declaration, but that seems unclean. Is there a better approach? To discover the members/methods of a class it looks like I can use: ObjectOperations op = pyEngine.Operations; object instance = op.Call("className"); foreach (string j in op.GetMemberNames("className")) { object member=op.GetMember(instance, j); Console.WriteLine(member.GetType()); /*once again, GetType() provides some info about the type of the member, but returns null sometimes*/ } Also, how do I get the parameters to a method? Thanks!

  Read the article

• Best way to track the stages of a form across different controllers - $_GET or routing

  - by chrisj

  Hi, I am in a bit of a dilemma about how best to handle the following situation. I have a long registration process on a site, where there are around 10 form sections to fill in. Some of these forms relate specifically to the user and their own personal data, while most of them relate to the user's pets - my current set up handles user specific forms in a User_Controller (e.g via methods like user/profile, user/household etc), and similarly the pet related forms are handled in a Pet_Controller (e.g pet/health). Whether or not all of these methods should be combined into a single Registration_Controller, I'm not sure - I'm open to any advice on that. Anyway, my main issue is that I want to generate a progress bar which shows how far along in the registration process each user is. As the urls in each form section can potentially be mapping to different controllers, I'm trying to find a clean way to extract which stage a person is at in the overall process. I could just use the query string to pass a stage parameter with each request, e.g user/profile?stage=1. Another way to do it potentially is to use routing - e.g the urls for each section of the form could be set up to be registration/stage/1, registration/stage/2 - then i could just map these urls to the appropriate controller/method behind the scenes. If this makes any sense at all, does anyone have any advice for me?

  Read the article

• Can I detect whether an object has called GC.SuppressFinalize?

  - by Joe White

  Is there a way to detect whether or not an object has called GC.SuppressFinalize? I have an object that looks something like this (full-blown Dispose pattern elided for clarity): public class ResourceWrapper { private readonly bool _ownsResource; private readonly UnmanagedResource _resource; public ResourceWrapper(UnmanagedResource resource, bool ownsResource) { _resource = resource; _ownsResource = ownsResource; if (!ownsResource) GC.SuppressFinalize(this); } ~ResourceWrapper() { if (_ownsResource) // clean up the unmanaged resource } } If the ownsResource constructor parameter is false, then the finalizer will have nothing to do -- so it seems reasonable (if a bit quirky) to call GC.SuppressFinalize right from the constructor. However, because this behavior is quirky, I'm very tempted to note it in an XML doc comment... and if I'm tempted to comment it, then I ought to write a unit test for it. But while System.GC has methods to set an object's finalizability (SuppressFinalize, ReRegisterForFinalize), I don't see any methods to get an object's finalizability. Is there any way to query whether GC.SuppressFinalize has been called on a given instance, short of buying Typemock or writing my own CLR host?

  Read the article

• How to marshal an object and its content (also objects)

  - by Waldo Spek

  I have a question for which I suspect the answer is a bit complex. At this moment I am programming a DLL (class library) in C#. This DLL uses a 3rd party library and therefore deals with 3rd party objects of which I do not have the source code. Now I am planning to create another DLL, which is going to be used in a later stadium in my application. This second DLL should use the 3rd party objects (with corresponding object states) created by the first DLL. Luckily the 3rd party objects extend the MarshalByRefObject class. I can marshal the objects using System.Runtime.Remoting.Marshal(...). I then serialize the objects using a BinaryFormatter and store the objects as a byte[] array. All goes well. I can deserialize and unmarshal in a the opposite way and end up with my original 3rd party objects...so it appears... Nevertheless, when calling methods on my 3rd party deserialized objects I get object internal exceptions. Normally these methods return other 3rd party objects, but (obviously - I guess) now these objects are missing because they weren't serialized. Now my global question: how would I go about marshalling/serializing all the objects which my 3rd party objects reference...and cascade down the "reference tree" to obtain a full and complete serialized object? Right now my guess is to preprocess: obtain all the objects and build my own custom object and serialize it. But I'm hoping there is some other way...

  Read the article

• how to Retrieve the parameters of document.write to detect the creation of dynamic tags

  - by user1335906

  In my Project i am supposed to identify the dynamically created tags which can be done in scripts through document.write("<script src='jquery.js'></script>") For this i used Regular expressions and my code is as follows function find_tag_docwrite(text) { var attrib=new Object; var pat_tag=/<((\S+)\s(.*))>/g; while(t=pat_tag.exec(text) { var tag=RegExp.$1; for(i=0;i<tags.length;i++) { var pat=/(\S+)=((['"]*)(\S+)(['"]*)\3)/g; while(p=pat.exec(f)) { attr=RegExp.$1;val=RegExp.$4; attrib[attr]=val; } } } } in the above function text is parameters of document.write function. Now through this code i am getting the tag names and all the attributes of the tags. But for the below example the above code is not working var gaJsHost = (("https:" == document.location.protocol) ? "https://ssl." : "http://www."); document.write(unescape("%3Cscript src='" + gaJsHost + "google-analytics.com/ga.js' type='text/javascript'%3E%3C/script%3E")); In such cases Regular expressions does not work so after searching some time where i found hooks on dom methods. so by using this i thought of creating hook for document.write method but i am able to understand how it is done i included the following code in my program but it is not working. function someFunction(text) { console.log(text); } document.write = someFunction; where text is the parameters of document.write. Another problem is After monitoring all the document.write methods using hooks again i have to use regex for finding tag creations. Is there Any alternative

  Read the article

• Agile methodologies. Is it a by-product of mind control techniques as NLP / Scientology?

  - by Bobb

  The more I read about contemporary methods combinging scrum, tdd and xp, the more I feel like I already seen the methods. I am not arguing that agile approach is much more progressive than older rigid structures like waterfall, what I am saying is that it seems to me that agile methodologies are ideal to be used as a nest for a brainwashing business. I read few articles which kept referring to authors which I checked afterwards and they call themselves - coaches, trainers (usual thing when NLP specialists are involved) with no apparent software development history. Also I met a guy who is a scrum faciltator (term widly used in relation to scientology) in a high profile company. I talked to him less than 5 min but I got complete feeling that he is either on drugs or he has been programmed by a powerful NLP specialist. The way to talk and his body movements witnessed he is not an average normal person (in terms of normal distribution :))... Please dont get me wrong. I am not a fun of conspiracy theories. But I had an experience with a member of church of scientology tried to invade a commercial firm and actually went half way through to very top in just 3 weeks. I saw his work. For now I have complete impression is that psycho manipulators are now invading IT industry through the convenient door of agile techniques. Anyone has the same feeling/thoughts?

  Read the article

• In Java, is there a gain in using interfaces for complex models?

  - by Gnoupi

  The title is hardly understandable, but I'm not sure how to summarize that another way. Any edit to clarify is welcome. I have been told, and recommended to use interfaces to improve performances, even in a case which doesn't especially call for the regular "interface" role. In this case, the objects are big models (in a MVC meaning), with many methods and fields. The "good use" that has been recommended to me is to create an interface, with its unique implementation. There won't be any other class implementing this interface, for sure. I have been told that this is better to do so, because it "exposes less" (or something close) to the other classes which will use methods from this class, as these objects are referring to the object from its interface (all public method from the implementation being reproduced in the interface). This seems quite strange to me, as it seems like a C++ use to me (with header files). There I see the point, but in Java? Is there really a point in making an interface for such unique implementation? I would really appreciate some clarifications on the topic, so I could justify not following such kind of behavior, and the hassle it creates from duplicating all declarations.

  Read the article

• How to Develop Dynamic Plug-In Based Functionality in C#

  - by Matthew

  Hello: I've been looking around for different methods of providing plug-in support for my application. Ideally, I will be creating a core functionality and based on different customers developing different plug-ins/addons such as importing, exporting data etc... What are the some methods available for making a C# application extensible via a plug-in architecture? Lets make up an example. If we have a program that consists of a main menu ( File, Edit, View, et al. ) along with a TreeView that displays different brands of cars grouped by manufacturer ( Ford, GM, for now). Right clicking on a car displays a context menu with the only option being 'delete car'. How could you develop the application so that plug-ins could be deployed so that you could allow one customer to see a new brand in the TreeView, let's say Honda, and also extent the car context menu so that they may now 'paint a car'? In Eclipse/RCP development this is easily handled by extension points and plug-ins. How does C# handle it? I've been looking into developing my own plug-in architecture and reading up on MEF.

  Read the article

• casting vs using the 'as' keyword in the CLR

  - by Frank V

  I'm learning about design patterns and because of that I've ended using a lot of interfaces. One of my "goals" is to program to an interface, not an implementation. What I've found is that I'm doing a lot of casting or object type conversion. What I'd like to know is if there is a difference between these two methods of conversion: public interface IMyInterface { void AMethod(); } public class MyClass : IMyInterface { public void AMethod() { //Do work } // other helper methods.... } public class Implementation { IMyInterface _MyObj; MyClass _myCls1; MyClass _myCls2; public Implementation() { _MyObj = new MyClass(); // What is the difference here: _myCls1 = (MyClass)_MyObj; _myCls2 = (_MyObj as MyClass); } } If there is a difference, is there a cost difference or how does this affect my program? Hopefully this makes sense. Sorry for the bad example; it is all I could think of... Update: What is "in general" the preferred method? (I had a question similar to this posted in the 'answers'. I moved it up here at the suggestion of Michael Haren. Also, I want to thank everyone who's provided insight and perspective on my question.

  Read the article

• Concrete examples of state sharing between multiple viewmodels (WPF MVVM)

  - by JohnMetta

  I have a WPF/Entity Framework (4.0) project with many objects. I'd like to build the application so that that I can have object selection state shared across viewmodels. For Example: We have Cars, Drivers, Passengers, and Cargo classes. We also have UserControls for CarList, DriverList, etc. and editor windows for CarEditor, DriverEditor, etc. Furthermore, we have viewmodels for all of these (CarListViewModel, DriverListViewModel, CargoEditorViewModel, etc). This all composes a dockable interface where the user can have multiple object lists, editors, and viewers open. What I want is a concrete code example of how to wireup multiple viewmodels so that selecting a car in the CarList will cause that car to go live in the CarEditorView, but also be selected in any other view for which the context is valid (such as a DriverByCarView- or just DriverList if there is a filter predicate). There are a number of suggestions and discussions based on this question. The two methods that seem to dominate are: 3018307: Discusses state sharing by mentioning a messaging subsystem 1159035: Discusses state sharing by using an enclosing viewmodel Is one of these approaches better than the other? Does anyone have a concrete example of either/both of these methods in the form of a write-up or small code project? I'm still learning WPF, so pointers to entry points for reading API fundamentals are appreciated, but looking at code examples is where I usually go. Thanks In case anyone is interested, here are some other similar discussions: 3816961: Discusses returning multiple viewmodels depending on object type (i.e. a collection of arbitrary types adhering to a specific interface) 1928130: Discusses whether it is a good idea to aggregate viewmodels as properties of other viewmodels (e.g. a MainWindow viewmodel composed of panel viewmodels) 1120061: Essentially discusses whether to have use a viewmodel-per-model strategy or a viewmodel-per-view-element strategy. 4244222: Discusses whether or not to nest the viewmodels when using a nested object hierarchy. 4429708: Discusses sharing collections between viewmodels directly, but doesn't go into detail. List item: Discusses managing multiple selections within a single viewmodel.

  Read the article

• Oddities in Linq-to-SQL generated code related to property change/changing events

  - by Lasse V. Karlsen

  I'm working on creating my own Linq-to-Sql generated classes in order to learn the concepts behind it all. I have some questions, if anyone knows the answer to one or more of these I'd be much obliged. The code below, and thus the questions, are from looking at code generated by creating a .DBML file in the Visual Studio 2010 designer, and inspecting the .Designer.cs file afterwards. 1. Why is INotifyPropertyChanging not passing the property name The event raising method is defined like this: protected virtual void SendPropertyChanging() Why isn't the name of the property that is changing passed to the event here? It is defined to be part of the EventArgs descendant that is passed to the event handler, but the method only passes an empty such value to it. 2. Why are the EntitySet<X> attach/detach methods not raising property changed? For an EntitySet<X> reference, the following two methods are generated: private void attach_EmailAddress1s(EmailAddress1 entity) { this.SendPropertyChanging(); entity.Person1 = this; } private void detach_EmailAddress1s(EmailAddress1 entity) { this.SendPropertyChanging(); entity.Person1 = null; } Why isn't SendPropertyChanged also called here? I'm sure I have more questions later, but for now these will suffice :)

  Read the article

• How do I execute queries upon DB connection in Rails?

  - by sycobuny

  I have certain initializing functions that I use to set up audit logging on the DB server side (ie, not rails) in PostgreSQL. At least one has to be issued (setting the current user) before inserting data into or updating any of the audited tables, or else the whole query will fail spectacularly. I can easily call these every time before running any save operation in the code, but DRY makes me think I should have the code repeated in as few places as possible, particularly since this diverges greatly from the ideal of database agnosticism. Currently I'm attempting to override ActiveRecord::Base.establish_connection in an initializer to set it up so that the queries are run as soon as I connect automatically, but it doesn't behave as I expect it to. Here is the code in the initializer: class ActiveRecord::Base # extend the class methods, not the instance methods class << self alias :old_establish_connection :establish_connection # hide the default def establish_connection(*args) ret = old_establish_connection(*args) # call the default # set up necessary session variables for audit logging # call these after calling default, to make sure conn is established 1st db = self.class.connection db.execute("SELECT SV.set('current_user', 'test@localhost')") db.execute("SELECT SV.set('audit_notes', NULL)") # end "empty variable" err ret # return the default's original value end end end puts "Loaded custom establish_connection into ActiveRecord::Base" sycobuny:~/rails$ ruby script/server = Booting WEBrick = Rails 2.3.5 application starting on http://0.0.0.0:3000 Loaded custom establish_connection into ActiveRecord::Base This doesn't give me any errors, and unfortunately I can't check what the method looks like internally (I was using ActiveRecord::Base.method(:establish_connection), but apparently that creates a new Method object each time it's called, which is seemingly worthless cause I can't check object_id for any worthwhile information and I also can't reverse the compilation). However, the code never seems to get called, because any attempt to run a save or an update on a database object fails as I predicted earlier. If this isn't a proper way to execute code immediately on connection to the database, then what is?

  Read the article

• unclear use of @property in window app using core data

  - by Matt

  Looking through a Window based application ive used to experiment with as a way of getting my head around core data, ive noticed that the appdelegate has the following code myAppDelegate.h #import <UIKit/UIKit.h> #import <CoreData/CoreData.h> @interface iCaptureFreeAppDelegate : NSObject <UIApplicationDelegate> { NSManagedObjectModel *managedObjectModel; NSManagedObjectContext *managedObjectContext; NSPersistentStoreCoordinator *persistentStoreCoordinator; UIWindow *window; UITabBarController *tabBarController; } myAppDelegate.m #import "myAppDelegate.h" @interface iCaptureFreeAppDelegate (PrivateCoreDataStack) @property (nonatomic, retain, readonly) NSManagedObjectModel *managedObjectModel; @property (nonatomic, retain) NSManagedObjectContext *managedObjectContext; @property (nonatomic, retain, readonly) NSPersistentStoreCoordinator *persistentStoreCoordinator; @end @implementation iCaptureFreeAppDelegate @synthesize window, tabBarController; // code .... // - (NSManagedObjectContext *) managedObjectContext { } - (NSManagedObjectModel *)managedObjectModel { } - (NSPersistentStoreCoordinator *)persistentStoreCoordinator { } // etc..... i want to understand a few things about what this project is doing why the properties in the category declaration? (if i delete the privateCoreDataStack category everything still works...) why the properties appear to be linked with the methods in the implementation ... managedObjectContext {} etc why the members in the .h file have the same name as the properties and the methods why code completion lets me use dot '.' to access the members but then fails on compilation say it cant find a getter thanks !

  Read the article

• Select multi-select form from array

  - by Budove

  Here's the issue. I have a database column called pymnt_meth_pref, which contains a comma separated string of payment methods chosen from a multiselect form. <td>Payment Methods Used:<br /> <input type="checkbox" name="pyment_meth_pref[]" value="Cash">I can pay with cash.<br /> <input type="checkbox" name="pyment_meth_pref[]" value="Check">I can pay by check.<br /> <input type="checkbox" name="pyment_meth_pref[]" value="Credit Card">I can pay by credit card.<br /> <input type="checkbox" name="pyment_meth_pref[]" value="Paypal">I can pay with Paypal.<br /> </td> This array is posted to a variable and turned into a comma separated string if (isset($_POST['pyment_meth_pref'])) $pymntmethpref = implode(", ", $_POST['pyment_meth_pref']); if (isset($_POST['pyment_meth_acc'])) $pymntmethacc = implode(", ", $_POST['pyment_meth_acc']); This is then inserted into the database as a comma separated string. What I would like to do, is take this string and apply the values to the original form when the user goes back to the form as 'pre-selected' checkboxes, indicated that the user has already selected those values previously, and keeping those values in the database if they choose to edit any other information in the form. I'm assuming this would need to be done with javascript but if there is a way to do it with PHP I'd rather do it that way.

  Read the article

< Previous Page | 181 182 183 184 185 186 187 188 189 190 191 192  | Next Page >