DevForce Support Forums

General Development : Parallel programming Net 4

Fri, 30 Jul 2010 21:37:09 +0000

Author: BillG
Subject: Parallel programming Net 4
Posted: Jul-30-2010 at 9:37pm

There is a new book out called Pro .NET 4 Parallel Programming in C#. I realize that multithreading is not a good fit with IdeaBlade but will I get any benefits from the new Parallel features of Net 4 in a n-tier WPF app using Devforce?

Bill

Object Mapping : Is it possible to create Class of ORM at run time at client side?

Fri, 30 Jul 2010 17:42:19 +0000

Author: ting
Subject: Is it possible to create Class of ORM at run time at client side?
Posted: Jul-30-2010 at 5:42pm

We actually provided this functionality in our DevForce Classic product. We lost this when moving to the Entity Framework because Microsoft does not support it. We are looking at a feature which would allow runtime type definition in the Entity Framework, but that is still a ways off.

There are also other schema structures that can approximate user-defined fields, but as you know they all have side effects and tradeoffs.

Troubleshooting : Navigation property null ref exception

Fri, 30 Jul 2010 16:53:39 +0000

Author: ting
Subject: Navigation property null ref exception
Posted: Jul-30-2010 at 4:53pm

Sure, can you send an email to IdeaBladeSupportTrack at ideablade dot com with [#7238] as the subject line? Once I have your contact information, I can walk you through what we found.

Edited by ting - Today at 4:54pm

Object Persistence : Dynamically building Predicate description

Fri, 30 Jul 2010 15:38:31 +0000

Author: BillG
Subject: Dynamically building Predicate description
Posted: Jul-30-2010 at 3:38pm

I have a search form that has 5 fields on it; ssn, cardno,employeeno, firstname, lastname. The user could fill in anyone of the fields and click find to find the member.

I am collecting the filled-in fields with a Query Object and passing it to my FetchMembers() method in my viewmodel.

Here is the code so far.

PredicateDescription p1 = null;

PredicateDescription p2 = null;

PredicateDescription p3 = null;

PredicateDescription p4 = null;

PredicateDescription p5 = null;

if(q.SSN != string.Empty)

p1 = PredicateBuilder.Make(typeof(Member), "SocSecNo", FilterOperator.IsEqualTo, q.SSN);

if(q.LastName != string.Empty)

p2 = PredicateBuilder.Make(typeof(Member), "LastName", FilterOperator.StartsWith, q.LastName);

if(q.FirstName != string.Empty)

p3 = PredicateBuilder.Make(typeof(Member), "FirstName", FilterOperator.StartsWith, q.FirstName);

if(q.EmployeeNo != string.Empty)

p4 = PredicateBuilder.Make(typeof(Member), "EmployeeNo", FilterOperator.IsEqualTo, q.EmployeeNo);

if(q.CardNo != 0)

p5 = PredicateBuilder.Make(typeof(Member), "CardNo", FilterOperator.IsEqualTo, q.CardNo);

var query = PredicateBuilder.FilterQuery(entityManager.Members, p1.And(p2).And(p3).And(p4).And(p5));

but not all the PredicateDescription objects might have values. How do I dynamically combine the p1, p2, p3 only if they are not null.

Bill

Getting Started : newbie

Fri, 30 Jul 2010 15:26:29 +0000

Author: davidklitzke
Subject: newbie
Posted: Jul-30-2010 at 3:26pm

As Ting said in an earlier post:

"I believe you just need to add:

using IdeaBlade.EntityModel;"

You also need to make sure that you add a reference to "IdeaBlade.Entity.SL" in your references for the client Silverlight project.

Deployment : Deploying Ideablade 2010 assemblies to the GAC

Fri, 30 Jul 2010 14:46:01 +0000

Author: davidklitzke
Subject: Deploying Ideablade 2010 assemblies to the GAC
Posted: Jul-30-2010 at 2:46pm

I don't know what problems that you are having.

Use gacutil.exe to list all of the assemblies (using "-l" option).

Use gacutil.exe to install an assembly (using "-i" option).

Use gacutil.exe to uninstlall an assembly (using "-u" option).

Is it the case that you have installed an IdeaBlade assembly into the GAC, but can't see the reference to it in "Add References"? In that case, you may need to modify the registry. For an example, look at "My_Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework\v4.0.30128\AssemblyFoldersEx\IdeaBlade2010".

Troubleshooting : Navigation property null ref exception

Fri, 30 Jul 2010 14:07:01 +0000

Author: akukucka
Subject: Navigation property null ref exception
Posted: Jul-30-2010 at 2:07pm

Hey ting,

I'm going to be troubleshooting this while Dave is away at VSLive next week.

I just talked to him and he mentioned that a mock .edmx file was created
from a SQL Server database that mimics our schema. He also mentioned that there were some differences between that .edmx and ours.

I was wondering if you could send me the associations from that file (in the SSDL and CSDL) so I could compare it to ours.

Thanks!

Getting Started : newbie

Fri, 30 Jul 2010 13:04:01 +0000

Author: jkattestaart
Subject: newbie
Posted: Jul-30-2010 at 1:04pm

Trying to get the quicky to work with the latest version v6.0.4.0 for Silverlight.

But i keep missing the ExecuteAsync method.

I read on the forum it was a problem with previous versions also.

The strange thing is that the SimpleSteps part 1 does work (they do have the asyncmethods)

But i can't find out what i am doing wrong. Juist following the readme....

Object Persistence : Insert NULL Into Database Field

Fri, 30 Jul 2010 12:22:44 +0000

Author: cjohnson84
Subject: Insert NULL Into Database Field
Posted: Jul-30-2010 at 12:22pm

Thank you for the suggestion! I was able to add a "BeforeSet" method to my injected Baseentity class to solve the problem.

Security : IEntityLoginManager Serialization Issues

Fri, 30 Jul 2010 10:30:23 +0000

Author: kimj
Subject: IEntityLoginManager Serialization Issues
Posted: Jul-30-2010 at 10:30am

There's a snippet here, along with more information -

http://www.ideablade.com:8989/xwiki/bin/view/Documentation/Security#HImplementingIEntityLoginManager

Object Persistence : Error upgrading to 6.0.4

Fri, 30 Jul 2010 09:16:55 +0000

Author: leeatkinson
Subject: Error upgrading to 6.0.4
Posted: Jul-30-2010 at 9:16am

Problem solved - I had an old version (with a different name) of the assembly that contained the model in the bin folder - so there were two models of the same name.

Lee

Object Persistence : Error upgrading to 6.0.4

Fri, 30 Jul 2010 08:58:08 +0000

Author: leeatkinson
Subject: Error upgrading to 6.0.4
Posted: Jul-30-2010 at 8:58am

Hi

I've upgraded to version 6.0.4 (from 6.0.3.1) but I'm getting this error when I attempt SaveChanged() on the entity manager:

"Key 'Context': The model's metadata artifact files (csdl, msl, ssdl) are either invalid or could not be found, either as resources in an assembly or loose in the output directory. Perhaps you have multiple assemblies containing the same metadata. Check the connection string for key 'Context', which says the artifact filenames are Model.csdl, Model.ssdl, and Model.msl. Do these names match the actual artifact filenames? All three root names (e.g., 'Model') should be the same and match the edmx filename unless you changed them deliberately."

An inner exception says:

Schema specified is not valid. Errors:
Model.csdl(30,4) : error 0019: Each type name in a schema must be unique. Type name 'Model.Entity' was already defined.
Model.csdl(39,4) : error 0019: Each type name in a schema must be unique. Type name 'Model.Entry' was already defined.

..etc (listing all entities and complex type has already been defined)

I'm not sure how to resolve this. It builds OK and the connection strings all look correct.

Regards

Lee

Getting Started : Tour Part 2 - can you keep the grid instead of a form

Fri, 30 Jul 2010 00:30:41 +0000

Author: WardBell
Subject: Tour Part 2 - can you keep the grid instead of a form
Posted: Jul-30-2010 at 12:30am

Here are some of my thoughts on these matters ... a condensation of my separate communications with alindzon ... reprised here for the DevForce audience.

I'm alergic to the RIA Services Domain Data Source (DDS) and all similar attempts to inscribe business logic in the XAML. Such logic doesn't belong there. When it's in the view, the view becomes an untestable, unmaintainable mess. I'm not saying this because it's fashionable to opine about "Separation of Concerns". I'm saying it from ugly experience trying to make sense of customer application mud balls.

The DDS is a terrible idea. I respect and like the people who wrote it. They know how I feel. I believe they agree with me. But their masters at Microsoft don't believe you are good enough or smart enough to write decent code. As the saying goes, no one ever went broke underestimating the intelligence of the masses.

Of course they are right in a way. If you keep dazzlling folks with single screen demos. If you consistently misguide them with bad practices. Sure ... they'll fall for it. And then you can say "we gave them what they wanted." No you didn't. You taught them to want the wrong thing.

Am I disgusted by it? Yes I am.

Our IdeaBlade hearts aren't that pure either. If we can't beat 'em, we might as well join them. Because you're now trained to want this crap, we'd like to show you how to tie your DevForce EntityManager into the DDS.

Unfortunately, Microsoft made sure we can't; the DDS UI control only works with RIA Services' Data Context. So (drum roll, please) we offer you our own look-alike, the IdeaBlade.Windows.SL.ObjectDataSource. Give it a try if you want to roll this way. It's based on the pre-release version of the DDS ... the design for RIA Services in Silverlight 3. The API has changed. Our ODS hasn't nor does it support the ability to run the search as you type. We'll bring it up-to-date eventually.

On the other hand, if you want my advice ... avoid it. Don't use the DDS. Don't use our ODS. Follow the View-ViewModel pattern ... which is not hard at all ... and spare yourself some future pain. You'll thank me later.

The fact is that you can easily do what the DDS does with simple code following the View-ViewModel pattern. Much has been said about MVVM. It boils down to this: the View's job is to look good; the ViewModel's job is to do the work; binding brings them together.

In this context it means that the UI controls for gathering the user's criteria ... the Company and Contact to search ... those controls go in the view. The logic to incorporate the user's criteria values into a query and run that query ... such logic belongs in the ViewModel.

You will bind the FilterCompany TextBox to the ViewModel ... just as you would any other data value. Let the binding push the search text into the ViewModel which senses the change, constructs the query, and executes it.

Ok .. it's not drag-and-drop. But you get code you can understand, debug, and test. If you need more features, you can add them. It's not a black box ... like the DDS ... where the minute you stray from the ordinary you're stuck. A black box is ok if it does something hard. This stuff is easy.

I already confessed that DevForce does not ship with a mechanism to watch your keystrokes and run the filter query automatically as you type.

Although you could write this yourself, you'd rather we took a crack at it first. So we will. And we'll give you the source. Then you can take it, or leave it, or do what you want with it.

We haven't written it yet. I've been thinking about how it might work, using alindzon's request as a guide.

Suppose �

1. Your TextBox is bound to the ViewModel.FilterCompany property via an attached property or "behavior" (TBD).

2. Your ViewModel has a method, �FilterFoo()�, that performs the filtered query; the method code might look like

var query = Manager.Foo

.AddFilter(FilterOperation.StartsWith, FilterCompany)

.AddFilter(FilterOperation.StartsWith, FilterContact)

// your grid�s ItemSource is bound to ResultList

Repository.ExecuteFilterQuery(ResultList, query);

3. �FilterFoo� was mentioned when you attached the TextBox property.

How bad would that be? Is this harder than RIA Services? To my eye it�s both simple and transparent.

The Behavior would be pretty simple. It listens for keystrokes. When the key stroking �stops� (i.e., there have been no new keystrokes after the prescribed delay), it invokes your FilterFoo(). The only trickiness is aggregating key stroke across the several controls that participate in the filtering (e.g., FilterCompany and FilterContact textboxes). You get that when you associate each TextBox with the ViewModel filtering method.

AddFilter (TBD) is an extension method on IQueryable that constructs the Where clause(s). It knows to skip the clause if FilterCompany is empty after trimming. You could add the Ignore list as a third parameter if you needed it.

This is DevForce as you know it. And you can use the Behavior anywhere. When you figure out how to trick out your grid with filter input controls, just attach the Behavior to it.

Dear reader ... let me know what you think.

Troubleshooting : Navigation property null ref exception

Thu, 29 Jul 2010 23:23:15 +0000

Author: ting
Subject: Navigation property null ref exception
Posted: Jul-29-2010 at 11:23pm

Thanks. We're taking a look at it.

Object Mapping : Is it possible to create Class of ORM at run time at client side?

Thu, 29 Jul 2010 22:45:03 +0000

Author: Thinkly
Subject: Is it possible to create Class of ORM at run time at client side?
Posted: Jul-29-2010 at 10:45pm

You mentioned "Provided you know how to dynamically construct the class definition on the client and server, this should work.". Yes, I know how to do it. So it seems I could find a solution.

You mentioned "If this is a large part of your application, I'm not sure if DevForce is a good fit for you though.". Yes, it is a large part of my application. I am sorry to know maybe DevForce is not a good fit.

I think my requirement is very common. For every application has to provide customization for end users, especially custom fields(columns) to existing tables(classes). Actually some XPO frameworks provide such a kind of functions. The reason I try to switch to DevForce is for richer functions, such as N-tier and security modules.

For the requirement of customization is common, why doesn't DevForce show a solution?

Thanks,

Ying

Getting Started : Help!

Thu, 29 Jul 2010 20:33:09 +0000

Author: BillG
Subject: Help!
Posted: Jul-29-2010 at 8:33pm

Download a free trial version from the IdeaBlade web site and after you register for the download, they will email you a trial key to insert when installing the software.

Object Mapping : Is it possible to create Class of ORM at run time at client side?

Thu, 29 Jul 2010 20:32:25 +0000

Author: ting
Subject: Is it possible to create Class of ORM at run time at client side?
Posted: Jul-29-2010 at 8:32pm

The only requirements for the POCO are:

1) The object must have a key.

2) The object must be serializable by WCF.

3) The POCO Service Provider class you write must return an IEnumerable.

Provided you know how to dynamically construct the class definition on the client and server, this should work.

Since a dynamic class is essentially used like a map / property bag / dictionary, you may find it easier to define a static POCO type that contains the key-value pairs. This simplifies the type construction, but still gives you access to all the runtime defined data.

If this is a large part of your application, I'm not sure if DevForce is a good fit for you though.

Security : IEntityLoginManager Serialization Issues

Thu, 29 Jul 2010 17:23:49 +0000

Author: mlens
Subject: IEntityLoginManager Serialization Issues
Posted: Jul-29-2010 at 5:23pm

Any chance you could post a sample implementation of the LoginManager under DevForce 2010? It's really confusing when you say GenericPrincipal and GenericIdentity are no longer supported but the login method of IEntityLoginManager returns IPrincipal....

Thanks

Deployment : Deploying Ideablade 2010 assemblies to the GAC

Thu, 29 Jul 2010 16:41:07 +0000

Author: rasmus
Subject: Deploying Ideablade 2010 assemblies to the GAC
Posted: Jul-29-2010 at 4:41pm

Hi

I seem to have problems deploying the Ideablade assemblies version 6.0.4.0 to the GAC. Are the assemblies missing a "strong name"?

Best regards,

Rasmus

Object Persistence : Asynchronous vs Synchronous Queries

Thu, 29 Jul 2010 14:43:29 +0000

Author: davidklitzke
Subject: Asynchronous vs Synchronous Queries
Posted: Jul-29-2010 at 2:43pm

Yes. You can use n-tier and BOS to benefit you.

http://www.ideablade.com:8989/xwiki/bin/view/Documentation/BusinessObjectServer#HRemoteServiceMethodCall28RSMC29Methods

Object Persistence : Asynchronous vs Synchronous Queries

Thu, 29 Jul 2010 14:17:38 +0000

Author: BillG
Subject: Asynchronous vs Synchronous Queries
Posted: Jul-29-2010 at 2:17pm

So I want to do a n-tier WPF app. I don't need the aynch queries but I would still like to use the BOS because there are some calculations that can run in queries on the server and only the results have to return or some don't have to return anything to the user but write directly to the database after the queries are done?

Will n-tier and BOS still benefit me here?

Bill

Object Persistence : Asynchronous vs Synchronous Queries

Thu, 29 Jul 2010 11:12:34 +0000

Author: davidklitzke
Subject: Asynchronous vs Synchronous Queries
Posted: Jul-29-2010 at 11:12am

The main reason that you would want to use an asynchronous query would be if you were writing a Silverlight application.

For more details on asynchrous queries, consult the DevForce Wiki. For example,

http://www.ideablade.com:8989/xwiki/bin/view/Documentation/AsynchronousCommunicationWithTheBusinessObjectServer#HAsynchronousQueries

Object Persistence : Silverlight: Dynamic OrderBy

Thu, 29 Jul 2010 10:43:41 +0000

Author: kimj
Subject: Silverlight: Dynamic OrderBy
Posted: Jul-29-2010 at 10:43am

Well, I used the term "test" quite loosely - I ran a single query and it worked. Here's the query -
     var customersQuery = _em1.Customers
        .Where(c => c.ContactTitle == "Sales Representative")
        .OrderBy("CompanyName")
        as EntityQuery;

      _em1.ExecuteQueryAsync(customersQuery, GotCustomers, null);

The changes to the DynamicLibrary were hacks, just to see if the code would compile. I'll post it here, but I want to emphasize this is neither tested nor endorsed by IdeaBlade, and certainly not supported - it's just my hacking to try the DL in Silverlight.

uploads/11/DynamicLibrary.cs.txt

Object Persistence : Silverlight: Dynamic OrderBy

Thu, 29 Jul 2010 09:24:53 +0000

Author: jkowalski
Subject: Silverlight: Dynamic OrderBy
Posted: Jul-29-2010 at 9:24am

Do you have the code that you test with?

Thanks for the info. I'll give it a try.

Object Persistence : Asynchronous vs Synchronous Queries

Thu, 29 Jul 2010 08:49:33 +0000

Author: BillG
Subject: Asynchronous vs Synchronous Queries
Posted: Jul-29-2010 at 8:49am

I am used to writing client server apps in which the user populates a grid of records with which they want to work. they click on a record, edit the record and save the record and move on to the next record. What benefit does Async queries do in this case, the user cannot select a record until all the rows come back and they see the one they want.

When would I want to do async queries vs. sync queries?

If I use sync queries do they still run through the BOS?

Bill

Data Verification (Validation) : Validate on button click?

Thu, 29 Jul 2010 07:37:55 +0000

Author: mikewishart
Subject: Validate on button click?
Posted: Jul-29-2010 at 7:37am

Thanks Greg. I came up with two ways to do it in an injected base class.

In the interest of helping any other developers with the same question, here's one way. (It's not fun finding forum posts with "I figured it out," but no answer as to how.) This way clears the error until Verify() is called again. Bindings need to include ValidatesOnDataErrors=true.

public abstract partial class EntityBase : IDataErrorInfo
{
private Dictionary _errorList;
private Dictionary ErrorList
{
get { return _errorList ?? (_errorList = new Dictionary()); }
}
private bool _isVerifying;

///

/// Verify the specific entity, setting errors on properties not passing validation.
///

///
/// True if the entity passes validation. False if there are errors.
///
public bool Verify()
{
    ErrorList.Clear();

    var verifiers = EntityAspect.VerifierEngine.Execute(this)
      .Where(v => ((v.ResultCode == VerifierResultCode.Error) || (v.ResultCode == VerifierResultCode.OkWarning))
                    && v.Verifier is PropertyValueVerifier).ToList();

_isVerifying = true;
try
{
    foreach (var verifierResult in verifiers)
    {
      var propertyName = ((PropertyValueVerifier)verifierResult.Verifier).PropertyName;

      if (ErrorList.ContainsKey(propertyName))
        ErrorList[propertyName] += Environment.NewLine + verifierResult.Message;
      else
        ErrorList.Add(propertyName, verifierResult.Message);

      EntityAspect.ForcePropertyChanged(new PropertyChangedEventArgs(propertyName));
    }
}
finally
{
    _isVerifying = false;
}

    return verifiers.Count == 0;
}

///

/// Hide the error whenever the property is changed until Verify() is called again.
///

protected override void OnPropertyChanged(PropertyChangedEventArgs e)
{
    base.OnPropertyChanged(e);
    if (_isVerifying) return;

    if (string.IsNullOrEmpty(e.PropertyName)) return;

    if (ErrorList.ContainsKey(e.PropertyName))
      ErrorList.Remove(e.PropertyName);
}

public new string this[string propertyName]
{
    get { return ErrorList.ContainsKey(propertyName) ? ErrorList[propertyName] : null; }
}

public string Error { get { throw new NotImplementedException(); } }
}

Edited by mikewishart - Today at 8:51am

Object Persistence : Azure storage & hosting support

Thu, 29 Jul 2010 04:38:02 +0000

Author: sarmaad
Subject: Azure storage & hosting support
Posted: Jul-29-2010 at 4:38am

I am currently in the process of researching the possibility to host the BOS in a web role or worker role, for one of our upcoming projects.

if you have any guidance or feedback regarding this possibility and if there are known issues that I might encounter, I would appreciate the heads up.

BTW, thanks for the POCOs. its working perfectly in my scenario.

Edited by sarmaad - Yesterday at 4:39am

Getting Started : Help!

Thu, 29 Jul 2010 02:22:37 +0000

Author: dino_erre@libero.it
Subject: Help!
Posted: Jul-29-2010 at 2:22am

Hi to all,

here's my problem: I've downloaded the free edition of DevForce that's been offered me via CodeProject.

Well: what I've to to write as product key value in the installation dialog???

Many thanks in advance

(from Italy)D. Rebuscini

Business Object Server : Simple Steps with ServerConsole

Wed, 28 Jul 2010 22:19:00 +0000

Author: BillG
Subject: Simple Steps with ServerConsole
Posted: Jul-28-2010 at 10:19pm

It worked YEAH!!!! I connected to the EntityService and then connected to the database and I could see my query running. Now do I get the results of the async query into a datagrid

MemberListView.xaml DataGrid = MembersGrid

MembersListView.xaml.cs this.DataContext = aMemberModel;

in FindMembers() of this class, I have a aModel.FetchMembers();

After my GoMembers() in my MemberViewModel is executed and the results are added to the members collection, how does that collection get back to the grid?

Bill

Getting Started : Lost Data Source

Wed, 28 Jul 2010 20:05:09 +0000

Author: WardBell
Subject: Lost Data Source
Posted: Jul-28-2010 at 8:05pm

Regarding "remembering the fields" ... there are so many better ways to do that.

Check out the new "Solution Navigator" among the Microsoft Productivity Power Tools Extensions for Visual Studio. Very cool. You can use its tree view to drill into any class ... including the properties of an Entity. You can tear away a sub-window that shows just the entity of interest. Drag it to your second monitor while your working on the view.

Edited by WardBell - Jul-28-2010 at 8:07pm