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  • Initializing entities vs having a constructor parameter

    - by Vee
    I'm working on a turn-based tile-based puzzle game, and to create new entities, I use this code: Field.CreateEntity(10, 5, Factory.Player()); This creates a new Player at [10; 5]. I'm using a factory-like class to create entities via composition. This is what the CreateEntity method looks like: public void CreateEntity(int mX, int mY, Entity mEntity) { mEntity.Field = this; TileManager.AddEntity(mEntity, true); GetTile(mX, mY).AddEntity(mEntity); mEntity.Initialize(); InvokeOnEntityCreated(mEntity); } Since many of the components (and also logic) of the entities require to know what the tile they're in is, or what the field they belong to is, I need to have mEntity.Initialize(); to know when the entity knows its own field and tile. The Initialize(); method contains a call to an event handler, so that I can do stuff like this in the factory class: result.OnInitialize += () => result.AddTags(TDLibConstants.GroundWalkableTag, TDLibConstants.TrapdoorTag); result.OnInitialize += () => result.AddComponents(new RenderComponent(), new ElementComponent(), new DirectionComponent()); This works so far, but it is not elegant and it's very open to bugs. I'm also using the same idea with components: they have a parameterless constructor, and when you call the AddComponent(mComponent); method in an entity, it is the entity's job to set the component's entity to itself. The alternative would be having a Field, int, int parameters in the factory class, to do stuff like: new Entity(Field, 10, 5); But I also don't like the fact that I have to create new entities like this. I would prefer creating entities via the Field object itself. How can I make entity/component creation more elegant and less prone to bugs?

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  • How does a GUI Framework work?

    - by AlexW.H.B.
    I have been all over the web looking for an answer to this, and my question is this: How does a GUI framework work? for instance how does Qt work, is there any books or wibsites on the topic of writing a GUI framework from scratch? and also does the framework have to call methods from the operating systems GUI framework? -- Thank you to any one who takes the time to try to answer this question, and forgive me if i misspelled anything.

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  • How to monetize and protect a engine's and its framework's copyrights and patents?

    - by Arthur Wulf White
    I created a game engine that handles: Rendering levels with 2d textured curved surfaces Collisions with curved surfaces Animationn paths on and navigation in 2d-sapce I have also made a framework for: Procedural organic level generation with round surfaces Level editing Light weight sprite design The engine and framework are written in AS3 and I am in the process of translating the code into HaXe to better support other platforms. I am also interested in adding Animated curved platforms More advanced level editing features Currently, I have a part time job and any time I spend on this engine is either taken out of my limited free time (I'm a student working to support myself through school) or out my time working at my job. I really believe this engine can make life much easier for people designing Tower Defence games, Shooters and and Platformers while also possibly improving their results. It could also support RTS, RPGs and racing games very well. It continains original algorithms that could be used for procedural generation of organic round and smooth levels. The algorithms I used are new and are not available in any other level editor I've seen. In order to constantly improve the Engine and have it tested thoroughly I think the best route is releasing it to the public. What are the best ways to benefit myself and others with my new framework? I want to have some lisence, allowing me to share the framework and still benefit from it. Any advice would be appreciated. This issue has been on my mind a lot this year. I am hoping to find a solution that will bring me some relief. I am thinking of designing three sample games, releasing them and starting a kickstarter, any advice and thoughts on the matter would be valuable. My goal is like Markus von Broady suggested, to get people involved in developing the engine and let people use it for games for either a symbolic fee or for free and charge for support. That or use some form of croud sourcing. Do I need to hire a lawyer to get some sort of legal document to protect my work?

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  • Entiity System with C++

    - by Dono
    I'm working on a game engine using the Entity System and I have some questions. How i see Entity System : Components : A class with attributs, set and get. Sprite Physicbody SpaceShip ... System : A class with a list of components. (Component logic) EntityManager Renderer Input Camera ... Entity : Just a empty class with a list of components. What i've done : Currently, i've got a program who allow me to do that : // Create a new entity/ Entity* entity = game.createEntity(); // Add some components. entity->addComponent( new TransformableComponent() ) ->setPosition( 15, 50 ) ->setRotation( 90 ) ->addComponent( new PhysicComponent() ) ->setMass( 70 ) ->addComponent( new SpriteComponent() ) ->setTexture( "name.png" ) ->addToSystem( new RendererSystem() ); My questions Did the system stock a list of components or a list of entities ? In the case where I stock a list of entities, I need to get the component of this entities on each frame, that's probably heavy isn't it ? Did the system stock a list of components or a list of entities ? In the case where I stock a list of entities, I need to get the component of this entities on each frame, that's probably heavy isn't it ?

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  • About Backward Compatibility of .NET Framework 4

    - by wuminqi
    We have an WPF Application build on .net framework 3.5. Some testers find if they uninstall .net framework 3.5, but install .net framework 4.0, our APP fails to launch itself. Dose this mean that .net framework 4.0 does not include all 3.5 libs, and users have to install .net 3.5 even though they have 4.0? I see here are some migration issues listed by Microsoft http://msdn.microsoft.com/en-us/library/ee941656.aspx#windows_presentation_foundation_wpf Are they all breaking changes so that the backward compatibility is ruined? Thanks

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  • why do you like zend-framework?

    - by user1400
    hello all i stared to learn zf for some month , i like to know why other programmer have chocen zend-framework and why do you like zend-framework? What reasons made you choose Zend-framework? has zend-framework Satisfied you? thanks

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  • Entity Framework - adding new items via a navigation property

    - by Robert
    I have come across what appears to be very peculiar behaviour using entity framework 4.0. I have a User entity, which has a Company (A Company has many Users). If I do this, everything works as expected and I get a nice shiny new user in the database: var company = _model.Companies.First(); company.Users.Add(new User(1, "John", "Smith")); _model.SaveChanges(); However, if I do this, then I get nothing new in the database, and no exceptions thrown: var existingUser = _model.Users.First(); var company = existingUser.Company; company.Users.Add(new User(1, "John", "Smith")); _model.SaveChanges(); So it appears that if I add a User to the Company that is pulled directly from the model, then everything works fine. However if the User is added to a Company that is pulled as a navigation property of another object, then it doesn't work. Can someone tell me if this is expected behaviour, or if there is something I can do to make it so that it is? Thanks!

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  • Entity Framework with MySQL - Timeout Expired while Generating Model

    - by Nathan Taylor
    I've constructed a database in MySQL and I am attempting to map it out with Entity Framework, but I start running into "GenerateSSDLException"s whenever I try to add more than about 20 tables to the EF context. An exception of type 'Microsoft.Data.Entity.Design.VisualStudio.ModelWizard.Engine.ModelBuilderEngine+GenerateSSDLException' occurred while attempting to update from the database. The exception message is: 'An error occurred while executing the command definition. See the inner exception for details.' Fatal error encountered during command execution. Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. There's nothing special about the affected tables, and it's never the same table(s), it's just that after a certain (unspecific) number of tables have been added, the context can no longer be updated without the "Timeout expired" error. Sometimes it's only one table left over, and sometimes it's three; results are pretty unpredictable. Furthermore, the variance in the number of tables which can be added before the error indicates to me that perhaps the problem lies in the size of the query being generated to update the context which includes both the existing table definitions, and also the new tables that are being added to it. Essentially, the SQL query is getting too large and it's failing to execute for some reason. If I generate the model with EdmGen2 it works without any errors, but the generated EDMX file cannot be updated within Visual Studio without producing the aforementioned exception. In all likelihood the source of this problem lies in the tool within Visual Studio given that EdmGen2 works fine, but I'm hoping that perhaps others could offer some advice on how to approach this very unique issue, because it seems like I'm not the only person experiencing it. One suggestion a colleague offered was maintaining two separate EBMX files with some table crossover, but that seems like a pretty ugly fix in my opinion. I suppose this is what I get for trying to use "new technology". :(

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  • Delphi Prism and LINQ to SQL / Entity Framework

    - by Vegar
    I have found many posts and examples of using LINQ-syntax in Delphi Prism (Oxygene), but I have never found anything on LINQ to SQL or Entity Framework. Is it possible to use LINQ to SQL or Entity Framework together with Prism? Where can I found such an example? Update: Olaf is giving an answer through his blog The question is now if any visual tools and code generation is provided, or if everything must be done by hand... Second update: Olaf has answered the tool/code generation-question in a comment on his site: The class designer is there, but there is no Pascal code gen. According to marc hoffman that is currently not on their list. For now you have to live with manual mapping. I guess, if you had Visual Studio (not just the VS shell), that you could add a C# library project to your solution, reference that from your Prism project. Then create the Table-Class mapping in the C# project using the visual designer. Maybe somewhat ugly, but possibly the key to get the Designer + CodeGen integrated into Prism. Who cares what language is used for the mapping . I will say this is a 1 - 0 to c# vs prism. If I did not care which language is used for the mapping - why should I care about which language is used for the rest?

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  • Entity Framework 4.0 Databinding with sorting not working

    - by Mike Gates
    I want to do something that I thought would be very simple. I want to bind a generated Entity Framework EntityCollection to a WPF DataGrid. I also want this grid to be sortable. I have tried all kinds of things to make this happen, including using a CollectionViewSource. However, nothing seems to work. Using a normal CollectionViewSource around the EntityCollection gives me: 'System.Windows.Data.BindingListCollectionView' view does not support sorting. Ok...strange. I would have thought this would work. Next on the CollectionViewSource, I try setting: CollectionViewType="ListCollectionView" Great, sorting now works. But wait, I can't add or remove entities using the grid now, presumably because ListCollectionView doesn't support this with an entity framework context. So, I guess I need to capture events coming out of the datagrid in order to add or remove entities manually from my context. Now I can't find an event to capture to detect an add...! Why is this so hard? This should be the standard "demo" case that Microsoft should have designed around. Any ideas?

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  • LINQ to Entity, using a SQL LIKE operator

    - by Mario
    I have a LINQ to ENTITY query that pulls from a table, but I need to be able to create a "fuzzy" type search. So I need to add a where clause that searches by lastname IF they add the criteria in the search box (Textbox, CAN be blank --- in which case it pulls EVERYTHING). Here is what I have so far: var query = from mem in context.Member orderby mem.LastName, mem.FirstName select new { FirstName = mem.FirstName, LastName = mem.LastName, }; That will pull everything out of the Member table that is in the Entity object. Then I have an addition to the logic: sLastName = formCollection["FuzzyLastName"].ToString(); if (!String.IsNullOrEmpty(sLastName)) query = query.Where(ln => ln.LastName.Contains(sLastName)); The problem is when the search button is pressed, nothing is returned (0 results). I have run the query against the SQL Server that I expect to happen here and it returns 6 results. This is the query I expect: SELECT mem.LastName, mem.FirstName FROM Members mem WHERE mem.LastName = 'xxx' (when xxx is entered into the textbox) Anyone see anything wrong with this?

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  • should I use Entity Framework instead of raw ADO.NET

    - by user110182
    I am new to CSLA and Entity Framework. I am creating a new CSLA / Silverlight application that will replace a 12 year old Win32 C++ system. The old system uses a custom DCOM business object library and uses ODBC to get to SQL Server. The new system will not immediately replace the old system -- they must coexist against the same database for years to come. At first I thought EF was the way to go since it is the latest and greatest. After making a small EF model and only 2 CSLA editable root objects (I will eventually have hundreds of objects as my DB has 800+ tables) I am seriously questioning the use of EF. In the current system I have the need many times to do fine detail performance tuning of the queries which I can do because of 100% control of generated SQL. But it seems in EF that so much happens behind the scenes that I lose that control. Article like http://toomanylayers.blogspot.com/2009/01/entity-framework-and-linq-to-sql.html don't help my impression of EF. People seem to like EF because of LINQ to EF but since my criteria is passed between client and server as criteria object it seems like I could build queries just as easily without LINQ. I understand in WCF RIA that there is query projection (or something like that) where I can do client side LINQ which does move to the server before translation into actual SQL so in that case I can see the benefit of EF, but not in CSLA. If I use raw ADO.NET, will I regret my decision 5 years from now? Has anyone else made this choice recently and which way did you go?

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  • should I use Entity Framework instead of raw ADO.NET

    - by user110182
    I am new to CSLA and Entity Framework. I am creating a new CSLA / Silverlight application that will replace a 12 year old Win32 C++ system. The old system uses a custom DCOM business object library and uses ODBC to get to SQL Server. The new system will not immediately replace the old system -- they must coexist against the same database for years to come. At first I thought EF was the way to go since it is the latest and greatest. After making a small EF model and only 2 CSLA editable root objects (I will eventually have hundreds of objects as my DB has 800+ tables) I am seriously questioning the use of EF. In the current system I have the need many times to do fine detail performance tuning of the queries which I can do because of 100% control of generated SQL. But it seems in EF that so much happens behind the scenes that I lose that control. Article like http://toomanylayers.blogspot.com/2009/01/entity-framework-and-linq-to-sql.html don't help my impression of EF. People seem to like EF because of LINQ to EF but since my criteria is passed between client and server as criteria object it seems like I could build queries just as easily without LINQ. I understand in WCF RIA that there is query projection (or something like that) where I can do client side LINQ which does move to the server before translation into actual SQL so in that case I can see the benefit of EF, but not in CSLA. If I use raw ADO.NET, will I regret my decision 5 years from now? Has anyone else made this choice recently and which way did you go?

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  • Implement DDD and drawing the line between the an Entity and value object

    - by William
    I am implementing an EMR project. I would like to apply a DDD based approach to the problem. I have identified the "Patient" as being the core object of the system. I understand Patient would be an entity object as well as an aggregrate. I have also identified that every patient must have a "Doctor" and "Medical Records". The medical records would encompass Labs, XRays, Encounter.... I believe those would be entity objects as well. Let us take a Encounter for example. My implementation currently has a few fields as "String" properties, which are the complaint, assessment and plan. The other items necessary for an Encounter are vitals. I have implemented vitals as a value object. Given that it will be necessary to retrieve vitals without haveing to retrieve each Encounter then do vitals become part of the Encounter aggregate and patient aggregrate. I am assuming I could view the Encounter as an aggregrate, because other items are spwaned from the Encounter like prescriptions, lab orders, xrays. Is approach right that I am taking in identifying my entities and aggregates. In the case of vitals, they are specific to a patient, but outside of that there is not any other identity associated with them.

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  • Problem with custom Equality in Entity Framework

    - by Shimmy
    Hello! I am using Entity Framework in my application. I implemented with the partial class of an entity the IEquatable<T> interface: Partial Class Address : Implements IEquatable(Of Address) 'Other part generated Public Overloads Function Equals(ByVal other As Address) As Boolean _ Implements System.IEquatable(Of Address).Equals If ReferenceEquals(Me, other) Then Return True Return AddressId = other.AddressId End Function Public Overrides Function Equals(ByVal obj As Object) As Boolean If obj Is Nothing Then Return MyBase.Equals(obj) If TypeOf obj Is Address Then Return Equals(DirectCast(obj, Address)) Else Return False End Function Public Overrides Function GetHashCode() As Integer Return AddressId.GetHashCode End Function End Class Now in my code I use it this way: Sub Main() Using e As New CompleteKitchenEntities Dim job = e.Job.FirstOrDefault Dim address As New Address() job.Addresses.Add(address) Dim contains1 = job.Addresses.Contains(address) 'True e.SaveChanges() Dim contains2 = job.Addresses.Contains(address) 'False 'The problem is that I can't remove it: Dim removed = job.Addresses.Remoeve(address) 'False End Using End Sub Note (I checked in the debugger visualizer) that the EntityCollection class stores its entities in HashSet so it has to do with the GetHashCode function, I want it to depend on the ID so entities are compared by their IDs. Please help me find what's wrong in the GetHashCode function (by ID) and what can I change to make it work. Thanks a lot.

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  • ASP.Net Entity Framework Repository & Linq

    - by Chris Klepeis
    My scenario: This is an ASP.NET 4.0 web app programmed via C# I implement a repository pattern. My repositorys all share the same ObjectContext, which is stored in httpContext.Items. Each repository creates a new ObjectSet of type E. Heres some code from my repository: public class Repository<E> : IRepository<E>, IDisposable where E : class { private DataModelContainer _context = ContextHelper<DataModelContainer>.GetCurrentContext(); private IObjectSet<E> _objectSet; private IObjectSet<E> objectSet { get { if (_objectSet == null) { _objectSet = this._context.CreateObjectSet<E>(); } return _objectSet; } } public IQueryable<E> GetQuery() { return objectSet; } Lets say I have 2 repositorys, 1 for states and 1 for countrys and want to create a linq query against both. Note that I use POCO classes with the entity framework. State and Country are 2 of these POCO classes. Repository stateRepo = new Repository<State>(); Repository countryRepo = new Repository<Country>(); IEnumerable<State> states = (from s in _stateRepo.GetQuery() join c in _countryRepo.GetQuery() on s.countryID equals c.countryID select s).ToList(); Debug.WriteLine(states.First().Country.country) essentially, I want to retrieve the state and the related country entity. The query only returns the state data... and I get a null argument exception on the Debug.WriteLine LazyLoading is disabled in my .edmx... thats the way I want it.

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  • Entity Framework: insert with one-to-one reference

    - by bomortensen
    Hi 'overflow! I'm having a bit trouble inserting into a mssql database using Entity Framework. There's two tables that I want to insert into, where one of table 1s fields is a foreign key in table2. This is the code I have so far: Media media = null; foreach(POI p in poiList) { media = new Media() { Path = p.ImagePath, Title = p.Title }; if (media != null && !context.Media.Any(me => me.Title == p.ImageTitle)) { context.AddToMedia(media); context.SaveChanges(); } PointOfInterest poi = new PointOfInterest() { Altitude = 2000.0, ID = p.ID, Latitude = p.Latitude, Longitude = p.Longitude, LatitudeRoute = p.LatitudeRoute, LongitudeRoute = p.LongitudeRoute, Description = p.Description, Title = p.Title, DefaultImageID = media.ID, }; context.AddToPointOfInterest(poi); } context.SaveChanges(); The following gives me this error: An object with the same key already exists in the ObjectStateManagerAn object with the same key already exists in the ObjectStateManager I'm still learning how to use the entity framework, so I don't even know if this would be the right approach to insert into two referenced tables. Can anyone enlighten me on this? :) Any help would be greatly appreciated! Thanks!

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  • Entity Framework & Binding syncronisation

    - by Jefim
    * EDIT * Sorry, I should make it clearer. Imagine I have an entity: public class MyObject { public string Name { get; set; } } And I have a ListBox: <ListBox x:Name="lbParts"> <ListBox.ItemTemplate> <DataTemplate> <TextBlock Text="{Binding Name}"/> </DataTemplate> </ListBox.ItemTemplate> </ListBox> I bind it to a collection in code-behind: ObjectQuery<MyObject> componentQuery = context.MyObjectSet; Binding b = new Binding(); b.Source = componentQuery; lbParts.SetBinding(ListBox.ItemsSourceProperty, b); And the on a button click I add an entity to the MyObjectSet: var myObject = new MyObject { Name = "Test" }; context.AddToMyObjectSet(myObject); Here is the problem - this object needs to update in the UI to. But it is not added there :( Help!

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  • Entity Framework Custom Query Function

    - by Josh
    I have an Entity Framework 4.0 Entity Object called Revision w/ Nullable DateEffectiveFrom and DateEffectiveTo dates. I was wondering if there was a short-hand way of querying an object's RevisionHistory based on a particular QueryDate date instead of having to use the following query structure: var results = EntityObject.Revisions.Where(x => (x.DateEffectiveFrom == null && x.DateEffectiveTo == null) || (x.DateEffectiveFrom == null && x.DateEffectiveTo >= QueryDate) || (x.DateEffectiveFrom <= QueryDate && x.DateEffectiveTo == null) || (x.DateEffectiveFrom <= QueryDate && x.DateEffectiveTo >= QueryDate)); I've tried creating the following boolean function in the Revision class: partial class Revision { public bool IsEffectiveOn(DateTime date) { return (x.DateEffectiveFrom == null && x.DateEffectiveTo == null) || (x.DateEffectiveFrom == null && x.DateEffectiveTo >= date) || (x.DateEffectiveFrom <= date && x.DateEffectiveTo == null) || (x.DateEffectiveFrom <= date && x.DateEffectiveTo >= date)); } ... } And then updating the query to: var results = EntityObject.Revisions.Where(x => x.IsEffectiveOn(QueryDate)); but this obviously doesn't translate to SQL. Any ideas would be much appreciated.

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  • Does WPF break an Entity Framework ObjectContext?

    - by David Veeneman
    I am getting started with Entity Framework 4, and I am getting ready to write a WPF demo app to learn EF4 better. My LINQ queries return IQueryable<T>, and I know I can drop those into an ObservableCollection<T> with the following code: IQueryable<Foo> fooList = from f in Foo orderby f.Title select f; var observableFooList = new ObservableCollection<Foo>(fooList); At that point, I can set the appropriate property on my view model to the observable collection, and I will get WPF data binding between the view and the view model property. Here is my question: Do I break the ObjectContext when I move my foo list to the observable collection? Or put another way, assuming I am otherwise handling my ObjectContext properly, will EF4 properly update the model (and the database)? The reason why I ask is this: NHibernate tracks objects at the collection level. If I move an NHibernate IList<T> to an observable collection, it breaks NHibernate's change tracking mechanism. That means I have to do some very complicated object wrapping to get NHibernate to work with WPF. I am looking at EF4 as a way to dispense with all that. So, to get EF4 working with WPF, is it as simple as dropping my IQueryable<T> results into an ObservableCollection<T>. Does that preserve change-tracking on my EDM entity objects? Thanks for your help.

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  • Auditing in Entity Framework.

    - by Gabriel Susai
    After going through Entity Framework I have a couple of questions on implementing auditing in Entity Framework. I want to store each column values that is created or updated to a different audit table. Rightnow I am calling SaveChanges(false) to save the records in the DB(still the changes in context is not reset). Then get the added | modified records and loop through the GetObjectStateEntries. But don't know how to get the values of the columns where their values are filled by stored proc. ie, createdate, modifieddate etc. Below is the sample code I am working on it. //Get the changed entires( ie, records) IEnumerable<ObjectStateEntry> changes = context.ObjectStateManager.GetObjectStateEntries(EntityState.Modified); //Iterate each ObjectStateEntry( for each record in the update/modified collection) foreach (ObjectStateEntry entry in changes) { //Iterate the columns in each record and get thier old and new value respectively foreach (var columnName in entry.GetModifiedProperties()) { string oldValue = entry.OriginalValues[columnName].ToString(); string newValue = entry.CurrentValues[columnName].ToString(); //Do Some Auditing by sending entityname, columnname, oldvalue, newvalue } } changes = context.ObjectStateManager.GetObjectStateEntries(EntityState.Added); foreach (ObjectStateEntry entry in changes) { if (entry.IsRelationship) continue; var columnNames = (from p in entry.EntitySet.ElementType.Members select p.Name).ToList(); foreach (var columnName in columnNames) { string newValue = entry.CurrentValues[columnName].ToString(); //Do Some Auditing by sending entityname, columnname, value } }

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  • getting expat to use .dtd for entity replacement in python

    - by nicolas78
    I'm trying to read in an xml file which looks like this <?xml version="1.0" encoding="ISO-8859-1"?> <!DOCTYPE dblp SYSTEM "dblp.dtd"> <dblp> <incollection> <author>Jos&eacute; A. Blakeley</author> </incollection> </dblp> The point that creates the problem looks is the Jos&eacute; A. Blakeley part: The parser calls its character handler twice, once with "Jos", once with " A. Blakeley". Now I understand this may be the correct behaviour if it doesn't know the eacute entity. However, this is defined in the dblp.dtd, which I have. I don't seem to be able to convince expat to use this file, though. All I can say is p = xml.parsers.expat.ParserCreate() # tried with and without following line p.SetParamEntityParsing(xml.parsers.expat.XML_PARAM_ENTITY_PARSING_ALWAYS) p.UseForeignDTD(True) f = open(dblp_file, "r") p.ParseFile(f) but expat still doesn't recognize my entity. Why is there no way to tell expat which DTD to use? I've tried putting the file into the same directory as the XML putting the file into the program's working directory replacing the reference in the xml file by an absolute path What am I missing? Thx.

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  • Understanding many to many relationships and Entity Framework

    - by Anders Svensson
    I'm trying to understand the Entity Framework, and I have a table "Users" and a table "Pages". These are related in a many-to-many relationship with a junction table "UserPages". First of all I'd like to know if I'm designing this relationship correctly using many-to-many: One user can visit multiple pages, and each page can be visited by multiple users..., so am I right in using many2many? Secondly, and more importantly, as I have understood m2m relationships, the User and Page tables should not repeat information. I.e. there should be only one record for each user and each page. But then in the entity framework, how am I able to add new visits to the same page for the same user? That is, I was thinking I could simply use the Count() method on the IEnumerable returned by a LINQ query to get the number of times a user has visited a certain page. But I see no way of doing that. In Linq to Sql I could access the junction table and add records there to reflect added visits to a certain page by a certain user, as many times as necessary. But in the EF I can't access the junction table. I can only go from User to a Pages collection and vice versa. I'm sure I'm misunderstanding relationships or something, but I just can't figure out how to model this. I could always have a Count column in the Page table, but as far as I have understood you're not supposed to design database tables like that, those values should be collected by queries... Please help me understand what I'm doing wrong...

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  • How can I share an entity framework model across website users

    - by richardmoss
    Hello, Currently my website is based around MVC and the Entity Framework running against a SQL Server 2005 database. So far, it has all been running very smoothly, and I really enjoy MVC and its slimmer more concise code (and no huge viewstates or soul destroying postbacks ;)) Recently I was working on upgrading the site to use a simple forum system, and this is where I started running into problems. When I was testing the site using two different browsers, if I created or replied to a post in one browser, the other browser couldn't see the post. At the moment, each visitor to the site gets their own copy of the entity model, which I store in their session data. Obviously this is the problem as updates to one model aren't getting carried to the other. As a test, I tried storing a single copy of the model which all visitors would access by assigning the model to a static variable. This worked, and both browsers could see each others modifications. However, it had its side effects. For example, if I fired up both browsers at the same time and the model was initialized, one browser would crash, and the other would work fine, despite me using a locking object so in theory one of them should have been delayed until the model was ready (of course I could have implemented this wrong ;)). Also, originally this site did use one model for all visitors and when it was live, it frequently shut down - killing the IIS application pool while it did. Now I'm not sure if this was related, but I don't really want to reintroduce whatever bug I had that caused this shut down. So, my question is a simple one really - what is the best way of either using the same model for all website users so they all see updates, or if they do have separate copies (which I imagine will have a performance impact in time) how can the models detect changes in the database and update themselves according. Thanks in advance for any advice! Regards; Richard Moss

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