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  • Using Entity Framework 4.0 with Code-First and POCO: How to Get Parent Object with All its Children

    - by SirEel
    I'm new to EF 4.0, so maybe this is an easy question. I've got VS2010 RC and the latest EF CTP. I'm trying to implement the "Foreign Keys" code-first example on the EF Team's Design Blog, http://blogs.msdn.com/efdesign/archive/2009/10/12/code-only-further-enhancements.aspx. public class Customer { public int Id { get; set; public string CustomerDescription { get; set; public IList<PurchaseOrder> PurchaseOrders { get; set; } } public class PurchaseOrder { public int Id { get; set; } public int CustomerId { get; set; } public Customer Customer { get; set; } public DateTime DateReceived { get; set; } } public class MyContext : ObjectContext { public RepositoryContext(EntityConnection connection) : base(connection){} public IObjectSet<Customer> Customers { get {return base.CreateObjectSet<Customer>();} } } I use a ContextBuilder to configure MyContext: { var builder = new ContextBuilder<MyContext>(); var customerConfig = _builder.Entity<Customer>(); customerConfig.Property(c => c.Id).IsIdentity(); var poConfig = _builder.Entity<PurchaseOrder>(); poConfig.Property(po => po.Id).IsIdentity(); poConfig.Relationship(po => po.Customer) .FromProperty(c => c.PurchaseOrders) .HasConstraint((po, c) => po.CustomerId == c.Id); ... } This works correctly when I'm adding new Customers, but not when I try to retrieve existing Customers. This code successfully saves a new Customer and all its child PurchaseOrders: using (var context = builder.Create(connection)) { context.Customers.AddObject(customer); context.SaveChanges(); } But this code only retrieves Customer objects; their PurchaseOrders lists are always empty. using (var context = _builder.Create(_conn)) { var customers = context.Customers.ToList(); } What else do I need to do to the ContextBuilder to make MyContext always retrieve all the PurchaseOrders with each Customer?

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  • Is it possible to supply the jQuery Validation plugin with a rules object?

    - by ethagnawl
    I took the rules that I'd been using to validate my form and broke them out into a JSON object, hoping to use the same set of rules for client/server validation. So, where I had: $(document.getElementById('new_listing_form')).validate({ rules: { apt: { required: true } } }); I'm attempting to use: var rules_obj = { apt: { required: true } }; $(document.getElementById('new_listing_form')).validate({ rules: rules_obj }); ... and the form is not being validated. Does anyone know if this is possible?

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  • How do you call a method for an Objective-C object's superclass from elsewhere?

    - by executor21
    If you're implementing a subclass, you can, within your implementation, explicitly call the superclass's method, even if you've overridden that method, i.e.: [self overriddenMethod]; //calls the subclass's method [super overriddenMethod]; //calls the superclass's method What if you want to call the superclass's method from somewhere outside the subclass's implementation, i.e.: [[object super] overriddenMethod]; //crashes Is this even possible? And by extension, is it possible to go up more than one level within the implementation, i.e.: [[super super] overriddenMethod]; //will this work?

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  • How do I write object classes effectively when dealing with table joins?

    - by Chris
    I should start by saying I'm not now, nor do I have any delusions I'll ever be a professional programmer so most of my skills have been learned from experience very much as a hobby. I learned PHP as it seemed a good simple introduction in certain areas and it allowed me to design simple web applications. When I learned about objects, classes etc the tutor's basic examnples covered the idea that as a rule of thumb each database table should have its own class. While that worked well for the photo gallery project we wrote, as it had very simple mysql queries, it's not working so well now my projects are getting more complex. If I require data from two separate tables which require a table join I've instead been ignoring the class altogether and handling it on a case by case basis, OR, even worse been combining some of the data into the class and the rest as a separate entity and doing two queries, which to me seems inefficient. As an example, when viewing content on a forum I wrote, if you view a thread, I retrieve data from the threads table, the posts table and the user table. The queries from the user and posts table are retrieved via a join and not instantiated as an object, whereas the thread data is called using my Threads class. So how do I get from my current state of affairs to something a little less 'stupid', for want of a better word. Right now I have a DB class that deals with connection and escaping values etc, a parent db query class that deals with the common queries and methods, and all of the other classes (Thread, Upload, Session, Photo and ones thats aren't used Post, User etc ) are children of that. Do I make a big posts class that has the relevant extra attributes that I retrieve from the users (and potentially threads) table? Do I have separate classes that populate each of their relevant attributes with a single query? If so how do I do that? Because of the way my classes are written, based on what I was taught, my db update row method, or insert method both just take the attributes as an array and update all of that, if I have extra attributes from other db tables in each class then how do I rewrite those methods as obbiously updating automatically like that would result in errors? In short I think my understanding is limited right now and I'd like some pointers when it comes to the fundamentals of how to write more complex classes.

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  • Access of private field of another object in copy constructors - Really a problem?

    - by DR
    In my Java application I have some copy-constructors like this public MyClass(MyClass src) { this.field1 = src.field1; this.field2 = src.field2; this.field3 = src.field3; ... } Now Netbeans 6.9 warns about this and I wonder what is wrong with this code? My concerns: Using the getters might introduce unwanted side-effects. The new object might no longer be considered a copy of the original. If it is recommended using the getters, wouldn't it be more consistent if one would use setters for the new instance as well?

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  • How to get jSon object in servlet from jsp?

    - by divi
    In jsp page i have written: var sel = document.getElementById("Wimax"); var ip = sel.options[sel.selectedIndex].value; var param; var url = 'ConfigurationServlet?ActionID=Configuration_Physical_Get'; httpRequest = new ActiveXObject("Microsoft.XMLHTTP"); httpRequest.open("POST", url, true); httpRequest.onreadystatechange = handler(){ if (httpRequest.readyState == 4) { if (httpRequest.status == 200) { param = 'ip='+ip; param += 'mmv='+mmv; param += "tab="+tab; }}; httpRequest.send(param); i want this param variable in my configurationServlet. Can any one tel me how to get this json object in servlet???

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  • Java: How to check if a date Object equals yesterday?

    - by tzippy
    Right now I am using this code Calendar cal = Calendar.getInstance(); SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); cal.set(cal.get(Calendar.YEAR), cal.get(Calendar.MONTH), cal.get(Calendar.DATE) - 1, 12, 0, 0); //Sets Calendar to "yeserday, 12am" if(sdf.format(getDateFromLine(line)).equals(sdf.format(cal.getTime()))) //getDateFromLine() returns a Date Object that is always at 12pm {...CODE There's got to be a smoother way to check if the date returned by getdateFromLine() is yesterday's date. Only the date matters, not the time. That's why I used SimpleDateFormat. Thanks for your help in advance!

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  • What is root reference ?

    - by DotNetGuy
    class GCTest { static Object r1; static void Main() { r1 = new Object(); Object r2 = new Object(); Object r3 = new Object(); System.GC.Collect(); // what can be reclaimed here ? r1 = null; r3.ToString(); System.GC.Collect(); // what can be reclaimed here ? } } // code from - DonBox's Essential .Net

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  • Which Java library lets me initialize an object's properties from a properties file?

    - by Kjetil Ødegaard
    Is there a Java library that lets you "deserialize" a properties file directly into an object instance? Example: say you have a file called init.properties: username=fisk password=frosk and a Java class with some properties: class Connection { private String username; private String password; public void setUsername(String username) { this.username = username; } public void setPassword(String password) { this.password = password; } } I want to do this: Connection c = MagicConfigurator.configure("init.properties", new Connection()) and have MagicConfigurator apply all the values from the properties file to the Connection instance. Is there a library with a class like this?

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  • What are the design patterns for HTML and CSS ?

    - by IHawk
    I know that is a very embracing question, but I have just started with Ruby on Rails, and still have a long way with CSS and HTML. There are lots of books about CSS and HTML patterns, but I would like to know what is really applied to actual webpages. For example, what's the best way of doing a simple webpage with a lateral menu, a logo on the top, and some text below? Ok, it seems stupid, but there's lot of ways of doing that, or not ? So, how can I learn this patterns and what are the real patterns ? Would appreciate suggestions of books, articles, etc.

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  • Fetch a Rails ActiveRecord 'datetime' attribute as a DateTime object.

    - by Tobias Cohen
    I have an attribute in one of my models that contains a Date/Time value, and is declared using t.datetime :ended_on in my migrations. When I fetch this value using myevent.ended_on, I get a Time object. The problem is that when I try to use this attribute as an axis in a Flotilla chart, it doesn't work properly because Flotilla only recognizes dates as Date or DateTime objects. I thought about writing a virtual attribute that will convert the existing Time value to a DateTime, but I'm wary of doing this, since I've heard that Time can't handle dates later than 2040, and I don't wish to risk creating a "2040 bug" to worry about later. Is there any way I can persuade ActiveRecord to return DateTime objects for this attribute instead of Time objects?

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  • jQuery mobile 1.1.0 slider: JS-object properties access?

    - by Koniak
    EDIT: This could be seen as a pure javascript objects question. The code can be found here: jquery.mobile-1.1.0.js I need to access properties of a jQuery mobile JS-object but is not sure how that is possible. In the jquery.mobile-1.1.0.js and mobile.slider is the following (see extend on line 5967): $.widget( "mobile.slider", $.mobile.widget, { ... _create: function() { ... $.extend( this, { slider: slider, handle: handle, valuebg: valuebg, dragging: false, beforeStart: null, userModified: false, mouseMoved: false }); Primarily the property I would like to read is the "dragging". I know i can execute the methods using: $("#slider").slider("refresh") Is there a similair way to access the properties? Thanks

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  • MVC design pattern in complex iPad app: is one fat controller acceptable?

    - by nutsmuggler
    I am building a complex iPad application; think of it as a scrapbook. For the purpose of this question, let's consider a page with two images over it. My main view displays my doc data rendered as a single UIImage; this because I need to do some global manipulation over them. This is my DisplayView. When editing I need to instantiate an EditorView with my two images as subviews; this way I can interact with a single image, (rotate it, scale it, move it). When editing is triggered, I hide my DisplayView and show my EditorView. In a iPhone app, I'd associate each main view (that is, a view filling the screen) to a view controller. The problem is here there is just one view controller; I've considered passing the EditorView via a modal view controller, but it's not an option (there a complex layout with a mask covering everything and palettes over it; rebuilding it in the EditorView would create duplicate code). Presently the EditorView incorporates some logic (loads data from the model, invokes some subviews for fine editing, saves data back to the model); EditorView subviews also incorporate some logic (I manipulate images and pass them back to the main EditorView). I feel this logic belongs more to a controller. On the other hand, I am not sure making my only view controller so fat a good idea. What is the best, cocoa-ish implementation of such a class structure? Feel free to ask for clarifications. Cheers.

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  • How can I pass an object as a parameter in the google app engine RPC flow?

    - by jimmartens
    I'm building a pretty basic app, and one thing I want to do is pass an object as a parameter up through the service - async - impl instead of passing up a million separate parameters. so in async, I do something like this: import shared.Profile; ... public interface ProfileServiceAsync { public void addProfile(Profile inProf, AsyncCallback<Void> async); Now, profile is a class in com. ... .shared and I have the following in my ... .gwt.xml <source path='shared'/> That being said when I try to compile I get this error. [ERROR] Errors in 'file:/D:/projects/eclipse/workspace/.../src/com/.../client/ProfileServiceAsync.java' [ERROR] Line 11: No source code is available for type shared.Profile; did you forget to inherit a required module? Any ideas on this?

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  • Fast check if an object will be successfully instantiated in PHP?

    - by Gremo
    How can I check if an object will be successfully instantiated with the given argument, without actually creating the instance? Actually I'm only checking (didn't tested this code, but should work fine...) the number of required parameters, ignoring types: // Filter definition and arguments as per configuration $filter = $container->getDefinition($serviceId); $args = $activeFilters[$filterName]; // Check number of required arguments vs arguments in config $constructor = $reflector->getConstructor(); $numRequired = $constructor->getNumberOfRequiredParameters(); $numSpecified = is_array($args) ? count($args) : 1; if($numRequired < $numSpecified) { throw new InvalidFilterDefinitionException( $serviceId, $numRequired, $numSpecified ); }

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  • What event should I handle to execute code when WinForms application switches from Run mode to Desig

    - by dotnetuser
    I am running a Windows form application and I need to execute a piece of code when I switch to design mode. I have a handler for the OnEnterDesignMode debugger event and this gets hit if I am debugging the application and then switch to design mode. However, this does not get hit if I initially start without debugging and then switch to design mode. What event do I need to handle in order that certain code is executed when switching from Run mode to Design mode?

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  • How can I access the int values of an object in an NSMutableArray?

    - by Daniel
    I try to access some values in a NSMutableArray I created, but I only get some numbers (address?) if I try to access them. I was able to initialize an array and can add and change objects with [myNSMutableArray addObject:[NSNumber numberWithInt:10]] and [myNSMutableArray replaceObjectAtIndex:0 withObject:[NSNumber numberWithInt:47] I also can print the value at index [0] with NSLog(@"%@", [myNSMutableArray objectAtIndex:0]); and I get 47 as expected. But how can I access the integer value of the object in the array so I can save it tomyIntValue?

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  • Javascript: How to filter object array based on attributes?

    - by JGreig
    I have the following JavaScript JSON array of real estate home objects: var json = { 'homes' : [ { "home_id":"1", "price":"925", "sqft":"1100", "num_of_beds":"2", "num_of_baths":"2.0", }, { "home_id":"2", "price":"1425", "sqft":"1900", "num_of_beds":"4", "num_of_baths":"2.5", }, // ... (more homes) ... ]} var xmlhttp = eval('(' + json + ')'); homes = xmlhttp.homes; What I would like to do is be able to perform a filter on the object to return a subset of "home" objects. For example, I want to be able to filter based on: price, sqft, num_of_beds, and num_of_baths. Question: How can I perform something in javascript like the pseudo-code below: var newArray = homes.filter( price <= 1000 & sqft >= 500 & num_of_beds >=2 & num_of_baths >= 2.5); Note, the syntax does not have to be exactly like above. This is just an example.

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  • NSManagedObject How To Reload

    - by crissag
    I have a view that consists of a table of existing objects and an Add button, which allows the user to create a new object. When the user presses Add, the object is created in the list view controller, so that the object will be part of that managed object context (via the NSEntityDescription insertNewObjectForEntityForName: method). The Add view has a property for the managed object. In the list view controller, I create an Add view controller, set the property to the managed object I created, and then push the Add view on to the navigation stack. In the Add view, I have two buttons for save and cancel. In the save, I save the managed object and pass the managed object back to the list view controller via a delegate method. If the user cancels, then I delete the object and pass nil back to the list view controller. The complication I am having in the add view is related to a UIImagePickerController. In the Add view, I have a button which allows the user to take a photo of the object (or use an existing photo from the photo library). However, the process of transferring to the UIImagePickerController and having the user use the camera, is resulting in a didReceiveMemoryWarning in the add view controller. Further, the view was unloaded, which also caused my NSManagedObject to get clobbered. My question is, how to you go about reloading the NSManagedObject in the case where it was released because of the low memory situation?

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  • 2-column table with two foreign keys. Performance/design question.

    - by Emanuel
    Hello everyone! I recently ran into a quite complex problem and after looking around a lot I couldn't find a solution to it. I've found answers to my questions many times before on stackoverflow.com, so I decided to post here. So I'm making a user/group managment system for a web-based project, and I'm storing all related data into a postgreSQL database. This system relies on three tables: USERS GROUPS GROUP_USERS The two first tables simply define all the users and all the groups on the site, and the last table, GROUP_USERS, stores the groups every user is part of. It only has two columns: USER_ID GROUP_ID Since every user can be a member of several groups, I decided to make a separate table for this purpose, rather than storing a comma separated column in the USERS-table. Now, both columns are foreign keys, and I want to make them both primary keys as well, this since each combination of USER_ID and GROUP_ID has to be unique, and if I give them the constraint UNIQUE pgAdmin tells me that each table should have at least one Primary key. But now I am stuck with what seems to be a lot of indexes and relations to a very small table only containing numbers. In the end, I want this table to be as fast as possible, even if containing tens of thousands of rows. Size on disk shouldn't be a problem since its just all numbers anyway, but it feels quite stupid to have a full-sized index refering to a smaller table. Should I stick with my current solution, store comma-separated values in a column in the USERS-table or is there any other solution I should be aware of. PS. I don't want to use an array-column, even if they are supported by postgreSQL. I want to be as generic as possible so I can switch database later on, if necessary. EDIT: I other words, will using a compound primary key and two foreign keys in one table with only two columns have a negative impact on performance rather than the opposite due to the size of the generated index? Thank you!

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  • How to reserve public API to internal usage in .NET?

    - by mark
    Dear ladies and sirs. Let me first present the case, which will explain my question. This is going to be a bit long, so I apologize in advance :-). I have objects and collections, which should support the Merge API (it is my custom API, the signature of which is immaterial for this question). This API must be internal, meaning only my framework should be allowed to invoke it. However, derived types should be able to override the basic implementation. The natural way to implement this pattern as I see it, is this: The Merge API is declared as part of some internal interface, let us say IMergeable. Because the interface is internal, derived types would not be able to implement it directly. Rather they must inherit it from a common base type. So, a common base type is introduced, which would implement the IMergeable interface explicitly, where the interface methods delegate to respective protected virtual methods, providing the default implementation. This way the API is only callable by my framework, but derived types may override the default implementation. The following code snippet demonstrates the concept: internal interface IMergeable { void Merge(object obj); } public class BaseFrameworkObject : IMergeable { protected virtual void Merge(object obj) { // The default implementation. } void IMergeable.Merge(object obj) { Merge(obj); } } public class SomeThirdPartyObject : BaseFrameworkObject { protected override void Merge(object obj) { // A derived type implementation. } } All is fine, provided a single common base type suffices, which is usually true for non collection types. The thing is that collections must be mergeable as well. Collections do not play nicely with the presented concept, because developers do not develop collections from the scratch. There are predefined implementations - observable, filtered, compound, read-only, remove-only, ordered, god-knows-what, ... They may be developed from scratch in-house, but once finished, they serve wide range of products and should never be tailored to some specific product. Which means, that either: they do not implement the IMergeable interface at all, because it is internal to some product the scope of the IMergeable interface is raised to public and the API becomes open and callable by all. Let us refer to these collections as standard collections. Anyway, the first option screws my framework, because now each possible standard collection type has to be paired with the respective framework version, augmenting the standard with the IMergeable interface implementation - this is so bad, I am not even considering it. The second option breaks the framework as well, because the IMergeable interface should be internal for a reason (whatever it is) and now this interface has to open to all. So what to do? My solution is this. make IMergeable public API, but add an extra parameter to the Merge method, I call it a security token. The interface implementation may check that the token references some internal object, which is never exposed to the outside. If this is the case, then the method was called from within the framework, otherwise - some outside API consumer attempted to invoke it and so the implementation can blow up with a SecurityException. Here is the modified code snippet demonstrating this concept: internal static class InternalApi { internal static readonly object Token = new object(); } public interface IMergeable { void Merge(object obj, object token); } public class BaseFrameworkObject : IMergeable { protected virtual void Merge(object obj) { // The default implementation. } public void Merge(object obj, object token) { if (!object.ReferenceEquals(token, InternalApi.Token)) { throw new SecurityException("bla bla bla"); } Merge(obj); } } public class SomeThirdPartyObject : BaseFrameworkObject { protected override void Merge(object obj) { // A derived type implementation. } } Of course, this is less explicit than having an internally scoped interface and the check is moved from the compile time to run time, yet this is the best I could come up with. Now, I have a gut feeling that there is a better way to solve the problem I have presented. I do not know, may be using some standard Code Access Security features? I have only vague understanding of it, but can LinkDemand attribute be somehow related to it? Anyway, I would like to hear other opinions. Thanks.

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