Hello,

I have a custom web control I've built, which uses child controls to build properties of the control.  (Like a DropDownList uses ListItem controls to build the list.)

The control looks like this:

<ns:MyControl ID="Main" runat="server">
	<Property1 Color="#fff" Text="Test content" />
	<Property2 Color="#000" Text="Second Test" />
</ns:MyControl>

I know there is a way to fix it, but the Microsoft documentation on this is incredibly confusing, and it seems there must be a better way.

This is all I found on the subject: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnaspp/html/ASPNet-AddDesignTimeSupport.asp

          (Scroll down to HTML View Support: Custom Schemas and Visual Studio Annotations)

Any help on how to do get Intellisense working for the child controls, and getting the validator to recoignize the child tags and properties would be greatly appreciated!

Mikhail Arkhipov (MSFT):

There is a limitation in how deep intellisense engine goes fetching types for a control. It does can find base class in a different assembly, but not a class that, say, represent a collection within the control. If you derive your control from an existing control you also have to make new inner property or collection class as well deriving them from the corresponding type in the base class. For example, if base is a Table and you derive myTable, you also have to derive myCell from Cell and myColumn from Column classes for the intellisense to find them.

Well, the control I created is not derived from anything other than "Control".  The child controls are parsed by the control with a ControlBuilder attribute and methods.  So I don't think VS will pick up any info about the Child controls unless I document them somehow.  The link I posted was a consufing article that seemed to suggest that I should create an XML namespace document, but gave no examples and no real detail about doing it. 

Any other ideas?

Here is a skeleton of the program code, with properties and irrelevant code stripped out.

<ControlBuilderAttribute(GetType(MyControlParseControlBuilder)), ToolboxData("<{0}:MyControl runat=server></{0}:MyControl>")> _
Public Class MyControl : Inherits Control : Implements INamingContainer
	'Properties defined here...

	Protected Overrides Sub Render(ByVal writer As System.Web.UI.HtmlTextWriter)
		'Rendering code here...
	End Sub

	Protected Overrides Sub AddParsedSubObject(ByVal obj As Object)

		If (TypeOf obj Is MyControlItem1) Then
			'Process property1...
		ElseIf (TypeOf obj Is MyControlItem2) Then
			'Process property2...
		End If

	End Sub

End Class

Public NotInheritable Class MyControlParseControlBuilder : Inherits ControlBuilder

	Public Overrides Function GetChildControlType(ByVal TagName As String, ByVal attributes As IDictionary) As Type

		'MyControlItem1 & 2 are classes defined elsewhere...
		If (String.Compare(TagName, "Property1", True) = 0) Then
			Return GetType(MyControlItem1)
		ElseIf (String.Compare(TagName, "Property2", True) = 0) Then
			Return GetType(MyControlItem2)
		End If

		Return Nothing
	End Function

	Public Overrides Sub AppendLiteralString(ByVal s As String)
	End Sub

End Class

Unfortunately, the editor isn't able to use the ControlBuilder to determine what the control persistence should be. (Property1 and Property2 are not really visible for inspection) Would it be possible to statically declare your inner properties instead of using a ControlBuilder? Our intellisense engine is able to handle static properties persisted as inner markup, but it isn't able to handle the dynamic markup scenario.

Thanks.

toddgrun:

Unfortunately, the editor isn't able to use the ControlBuilder to determine what the control persistence should be. (Property1 and Property2 are not really visible for inspection) Would it be possible to statically declare your inner properties instead of using a ControlBuilder? Our intellisense engine is able to handle static properties persisted as inner markup, but it isn't able to handle the dynamic markup scenario.

Thanks.

The reason for using the ControlBuilder is that the number of child elements is dynamic.  It could be 1 or 100, or anything in between.  So I don't think there's a way to do it statically.

Seems that there must be a way to document the properties in some fashion, even if I have to figure out how to do it with an XML namespace.  Is there anything I can do?  Is there any documentation someplace that would help me figure it out with an example or two?

Hey, I just figured it out, thanks to Nikhil Kothari!

I needed to add the PersistChildren() attribute to the class definition, as follows:

<ControlBuilderAttribute(GetType(MyControlParseControlBuilder)), PersistChildren(False, True), ToolboxData("<{0}:MyControl runat=server></{0}:MyControl>")> _
Public Class MyControl : Inherits Control : Implements INamingContainer

The first argument (False) indicates that the inner content will be treated as control properties, rather than controls, and the second argument (True) indicates that I am using customized persistence.

The PersistChildrenAttribute decorator basically tells us to turn off our intellisense engine inside the control. Note that you won't get any stmt completion for your control's inner markup, whereas if you were able to create a child control collection, you could get intellisense. I'm glad to hear that this solves the issue for you.

Nevermind, I just figured that one out too.  There is a good example here: http://samples.gotdotnet.com/quickstart/aspplus/doc/webctrlauthoring.aspx

(Scroll down to "Overriding Control Parsing".)

Nevermind, I just figured that one out too.  There is a good example here: http://samples.gotdotnet.com/quickstart/aspplus/doc/webctrlauthoring.aspx

(Scroll down to "Overriding Control Parsing".)

Nevermind, I just figured that one out too.  There is a good example here: http://samples.gotdotnet.com/quickstart/aspplus/doc/webctrlauthoring.aspx

(Scroll down to "Overriding Control Parsing".)