ObjectDataSource : Manually controlling the sorting expression.

By default the GenWise ASP.NET Templates uses the object datasource SortParamterName. When that property is used , the objectdatasource will manipulate internally the sort expression (change to asc , desc) .

  269     ObjectDataSource runat="server" ID="ObjectDataSource1" TypeName="BOLayer.CustomerFactory"

  270                 SelectCountMethod="Count" EnablePaging="True" UpdateMethod="Save" DeleteMethod="Delete"

  271                 SortParameterName="pSortExpression" MaximumRowsParameterName="pMaxResult" StartRowIndexParameterName="pFirstResult"

  272                 SelectMethod="GetAll">

  273                 

  274                     Parameter Name="pSortExpression">Parameter>

  275                     Parameter Name="pCriteria">Parameter>

  276                 

  277                 

  278                     Parameter Name="CustomerID">Parameter>

  279                 

  280             ObjectDataSource>

For more advanced sorting scenarios you might want to manually control what's passed to the pSortExpression method parameter. This can be done in the following way :

Subscribe to the ObjectDataSource Selecting method (genwise does that automatically)

   44 ObjectDataSource1.Selecting += new ObjectDataSourceSelectingEventHandler(ObjectDataSource1_Selecting);

  253    protected void ObjectDataSource1_Selecting(object pSender, ObjectDataSourceSelectingEventArgs pEventArgs)

  254         {

  255             if (pEventArgs.ExecutingSelectCount)

  256                 pEventArgs.InputParameters.Remove("pSortExpression");

  257             else

  258                 pEventArgs.InputParameters["pSortExpression"] = _newSortExpression;

  259 

  260             pEventArgs.InputParameters["pCriteria"] = Browse1_GetCriteria();

  261         }

Where does _newSortExpression come from ? 

  198         string _newSortExpression = null;

  199         protected void Browse1_Sorting(object pSender, GridViewSortEventArgs pEventArgs)

  200         {

  201             // Calls this method to adapt the sort syntax (required for Composite sorting).

  202             _newSortExpression = WebUtils.SortExpressionTransformer(pEventArgs);

  203             pEventArgs.Cancel = true;

  204         }

SortExpression Tranformer takes the ObjectDataSource parameters and manipulates them to make them compatible with the GenWise Factories sorting syntax.

Below is the code of this method:

   63   public static string SortExpressionTransformer(GridViewSortEventArgs pEventArgs)

   64     {

   65         if (pEventArgs == null) throw new ArgumentNullException("pEventArgs");

   66 

   67         if (pEventArgs.SortDirection == SortDirection.Ascending)

   68         {

   69             return pEventArgs.SortExpression;

   70         }

   71 

   72         string newSortExpression = pEventArgs.SortExpression;

   73         string DESC = " DESC";

   74 

   75         if (pEventArgs.SortDirection == SortDirection.Descending)

   76         {

   77             if (pEventArgs.SortExpression.Contains(","))

   78             {

   79                 // Case : We have a composite sorting ( Field1,Field2) 

   80                 newSortExpression = string.Empty;

   81                 string[] sortParts = pEventArgs.SortExpression.Split(',');

   82                 for (int i = 0; i <> 
   83                 {
 
   84                     string sortPart = sortParts[i];
 
   85 
 
   86                     int sortDirectionIndex = sortPart.IndexOf(DESC);
 
   87                     bool isDescending = (sortDirectionIndex > -1);
 
   88 
 
   89                     string property = sortPart;
 
   90                     if (isDescending)
 
   91                     {
 
   92                         // sta : udpate templates.
 
   93                         //property = sortPart.Substring(0, (sortPart.Length - sortDirectionIndex + 1));
 
   94                         property = sortPart.Substring(0, (sortPart.Length - sortDirectionIndex + 1 + DESC.Length));
 
   95                     }
 
   96 
 
   97                     if (i > 0) newSortExpression += ",";
 
   98                     newSortExpression += property;
 
   99 
 
  100                     // Only add the DESC to all except the last (Last one will be controlled automatically by the object datasource.
 
  101                     if (!isDescending)
 
  102                     {
 
  103                         if (i < (sortParts.Length - 1))
 
  104                             newSortExpression +=  DESC ;
 
  105                     }
 
  106                 }
 
  107                 pEventArgs.SortExpression = newSortExpression;
 
  108             }
 
  109         }
 
  110         return newSortExpression;
 
  111     }
 

GenWise generated project added to vs.net solution using Source control.

Several customers have asked me how they can integrate an existing GenWise project into their vs.net solutions. To be more specific, GenWise already generates 100% compatible project files, so what's the problem?

Well, If you want to add the generated project into an existing solution and at the same time you can to keep that solution in source safe ( or in sourcegear vault which I use and recommend) then you might hit some little problems.

Problem #1 : Every time you regenerate the project is seen as a "new" project for the solution.
The reason behind this is that when you add the project to the solution the .proj file is modified with specific source control information + and ID (Guid) is given, etc.
To solve this problem you can "copy/paste" this information from the "modified" version of the project file INTO the GenWise project, so when you re-generate you don't loose this info .

Click on the image to enlarge an example for the solution to problem #1.




Problem #2 : After you have added the project to a source control provider ( vss or vault) all the files will be automatically read-only (by default) so you need to explicity do a complete project check out before you use the regenerate options from GenWise.

Custom Security MembershipProvider & Login attempts (MaxInvalidPasswordAttempts)

The Problem : Have a limit on the amount of possible logins when using a Custom provider.

Let's say that you write your own MembershipProvider (quite common if you want to use your own object model ..)

   11   public class MyMemberShipProvider : System.Web.Security.MembershipProvider

   12     {

Like many other articles explain, the most important Method is ValidateUser.
What very people often "forget"to mention is that all other features are not present in your provider. For example, the MaxInvalidPasswordAttempts is a property that you can set it to any number but nothing is going to happen.

In a Nutshell : you need to implement it yourself.

What I am showning below is a quite simple version but it's proves the point.

  180     public override System.Boolean ValidateUser(System.String pUsername, System.String pPassword)

  181         {

  182             if (pUsername.Equals("demo") && pPassword.Equals("demo"))

  183             {

  184                 return LoginSuccess();

  185             }

  186             return LoginFailed();

  187 

  188         }

LoginFailed() will basically return false but also it would do the check if another attempt should be granted or not:

  211     private bool LoginFailed()

  212         {

  213             //WebFailureAuditEvent.Raise(WebEventCodes.AuditFormsAuthenticationFailure);

  214             LoginFailuresCount++;

  215             if (LoginFailuresCount >= this.MaxInvalidPasswordAttempts)

  216                 throw new Exception("OK, that's it. Bye Bye");

  217 

  218             return false;

  219 

  220         }

You need to keep track of how many login failures :

  197  protected int LoginFailuresCount

  198         {

  199             get

  200             {

  201                 if (HttpContext.Current.Session["Failures"] == null)

  202                     return 0;

  203                 return (int)HttpContext.Current.Session["Failures"];

  204             }

  205             set

  206             {

  207                 HttpContext.Current.Session["Failures"] = value;

  208             }

  209         }

In the commented line where I was trying to Raise the "WebFailureAuditEvent", I read somewhere that I was a good idea to raise it but could not find any reference or example. If anybody knows how to do it --> please let me know.

Note: An improvement to this model would be to support "PasswordAttemptWindow" which in this case I did not implement.

Note: New Browser == new Session so it's not really state-of-the-art security technique it's a basic

DSL - How to use DesignVerbs with shapes?

Although I've previously wrote in this post about how you could add Menu Commands to shapes, I am still searching for alternative (maybe better?) approaches for exposing commands from my domain classes.

Why? Because the other way is too complex (too many steps) and I have many actions/commands.

Every time you click on a shape, a PropertyGrid is used to expose the ShapeProperties + DomainProperties (yes, they are merged in the PropertyGrid).

So, one natural approach would be to think "Why not add DesignVerbs as done for Custom Controls?". This question was asked in the msdn forum with null replied (until now ;) )

What I did was combined the idea from Geoff Appleby with a Custom partial class for each shape (off course only for the ones you need some special command/verb).

This is how the final solution looks like:

As you can see, "My Custom Action" and "Synchronize" are my exposed Actions/Commands. Here is the code that defines what to show:

public DesignerVerbCollection Verbs
{
get {
DesignerVerbCollection verbs = new DesignerVerbCollection();
verbs.Add( new DesignerVerb("My Custom Action", new EventHandler(ExecuteAction1) ));
verbs.Add(new DesignerVerb("Synchronize", new EventHandler(Synchronize)));
return verbs;
}
}

private void Synchronize(object sender, EventArgs e)
{
ExampleElement element = this.ModelElement as ExampleElement;
if ( element == null ) return;
MessageBox.Show("Action 1 was executed on model Element:" + element.Name);
}

Off course it's not only that since you need to also implement 2 interfaces:

public partial class ExampleShape : DslDiagrams::NodeShape, IComponent, IVerbsHost
{

private ISite _site;

public ISite Site
{
get
{
if (_site == null)
_site = new VerbSite(this, new VerbMenuCommandService(this));
return _site;
}
set { _site = value; }
}

public interface IVerbsHost { DesignerVerbCollection Verbs { get; }}

Drop me an e-mail if you are interested in the complete source code ( blogger does not have file upload i think.. need to check..)

TODO : Next I would like to combine both techniques be able to access this design verbs not only from the PropertyGrid but also from the Shape's right mouse and DSL Explorer.

Cleaning "old" DSL Languages

If you are , like me, new to DSLs you will end up creating many DSL projects. ;)

After a while your "New Item" dialog will end up looking really crowded.

Don't ask me why but the "Reset the Microsoft Visual Studio 2008 Experimental hive" option does not seem to work on all cases, and I still have several old dsl languages which won't go away. ( Note: I guess that the reset option by design will not mess us local user's document as explained below)

First, I've tried , with no success, to follow the tip from "El Bruno" (spanish blog) .

What's the solution ?

You need to "remove"all the zip files in the following directories:

C:\Users\\Documents\Visual Studio 2008\My Exported Templates
C:\Users\\Documents\Visual Studio 2008\Templates\ItemTemplates\CSharp\1033
C:\Users\\Documents\Visual Studio 2008\Templates\ItemTemplates\VisualBasic\1033

Note: On every DSLPackage build , a new file .zip will be created and placed on that directory. So before trying to open your DSL make sure you build the project first.