I'm a newbie to Dynamic Data so I tried this a number of ways before posting here.  Basically, I'd like to remove certain columns from the gridview and have it apply to all tables (otherwise I'd be doing it in the custom pages area).  Specifically, I only want required columns to be listed here.  I tried:

• Looping through the columns in the metatable.  Not a problem, but I have no way to match up the metacolumn with the gridview column.  Apparently, the gridview columns are only accessible by their integer index value and they do not match up with the integer index value in the metatable.
• I tried matching them by the header text property of the gridview column against the name of the metacolumn, but there doesn't seem to by any header text value although the UI clearly shows it.
  
•  I tried modifying the .dbml file - setting the access to not be public - but any changes in the .dbml file itself cause a runtime error.

There is a way to do this though it's somewhat advanced.  Try this:

• Implement IAutoFieldGenerator on some class.
• In your GenerateFields(), return some arbitrary collection of DynamicField's
• In the page code, set the GridView's ColumnsGenerator to your implementation.

Let us know how this goes!

David

I'm not following item 2 -  return some arbitrary collection of DynamicField's

 Would this be specific to a table?
 

Yes, your implemenation of that interface would be passed the MetaTable it should target (it's available in the Page, e.g. through the DataSource).  Then you would enumerate through the MetaColumns, and for those you want to add (based on your own criteria) you'd add a DynamicField to the collection.

David

 I appreciate your help and patience.  I've got some puesdo code for item 2, but didn't get too far.

1    Imports Microsoft.VisualBasic
2    Imports System.Web.DynamicData
3    
4    Public Class ListDataSource
5        Implements IAutoFieldGenerator 'SAYS TYPE IS NOT DEFINED, I DONT SEE WHERE IT RESIDES
6    
7        Protected table As MetaTable
8    
9        Function GenerateFields() As ArrayList
10           ' this will store the return value
11           Dim oDataField As New ArrayList
12   
13           ' loop through the available columns
14           For Each col As MetaColumn In table.Columns
15   
16               ' remove columns that are not required
17               If Not col.IsRequired Then
18                   ' NOT SURE WHAT CODE WOULD GO HERE TO REMOVE COLUMN OR BUILD TO ARRAYLIST
19   
20               End If
21           Next
22       End Function
23   End Class

One other thing in jumping ahead to number 3 - the intellisense does not list a member for the gridview called ColumnsGenerator.  Is that just a bug in the intellisense?

Here is an example of what you might do:

            public ICollection GenerateFields(Control control) {
                var fields = new List();
                foreach (MetaColumn column in table.Columns) {
                    if ([your custom check to decide to skip a column])
                        continue;

                    fields.Add(new DynamicField() { DataField = column.Name });
                }

                return fields;
            }

The intellisense is broken because the simplistic install batch file doesn't copy the updated System.Web to \windows\Microsoft.NET\Framework\v2.0.50727.  Potentially, you could copy it manually, though you should be able to run fine without it.

David

Again, much thanks :)

Here is the VB code I came up with, placed it in the App_Code folder called ListDataSource.vb

1    Imports Microsoft.VisualBasic
2    Imports System.Web
3    Imports System.Web.UI
4    Imports System.Web.DynamicData
5    Imports System.Collections.Generic
6    
7    
8    Public Class ListDataSource
9        Implements IAutoFieldGenerator
10   
11       Protected table As MetaTable
12   
13       Public Function GenerateFields(ByVal control As Control) As ICollection
14           Dim oFields = New List(Of DynamicField)
15           For Each col As MetaColumn In table.Columns
16               If col.IsRequired Then
17                   Dim oDF As New DynamicField
18                   oDF.DataField = col.Name
19                   oFields.Add(oDF)
20               End If
21           Next
22           Return oFields
23       End Function
24   
25   End Class

 In the actual list page, I am implementing the new class this way.

Protected Sub Page_Init(ByVal sender As Object, ByVal e As EventArgs)
        DynamicDataManager1.RegisterControl(GridView1)
        ListDataSource.GenerateFields(GridView1)
    End Sub

 And this is the error message I get which makes no sense to me.  Everything appears to be correct.

Compiler Error Message: BC30149: Class 'ListDataSource' must implement 'Function GenerateFields(control As Control) As Collections.ICollection' for interface 'System.Web.UI.IAutoFieldGenerator'.
 

Try:

GridView1.ColumnsGenerator = [instance of your class that implements the interface]

David

Below is the code in C# for those who may be interested.

Now, is there a similar technique that can be used for DetailsView?

This does not work --> DetailsView1.ColumnsGenerator = new ListDataSource(table);

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Xml.Linq;
using System.Web.DynamicData;

public partial class List : System.Web.UI.Page
{
	protected MetaTable table;

	protected void Page_Init(object sender, EventArgs e)
	{
		DynamicDataManager1.RegisterControl(GridView1);
	}

	protected void Page_Load(object sender, EventArgs e)
	{
		table = GridDataSource.GetTable();
		Title = table.DisplayName;

		GridView1.ColumnsGenerator = new ListDataSource(table);

		InsertHyperLink.NavigateUrl = table.GetActionPath(PageAction.Insert);

		// Disable various options if the table is readonly
		if (table.IsReadOnly)
		{
			GridView1.Columns.RemoveAt(0);
			InsertHyperLink.Visible = false;
		}
	}

	protected void OnFilterSelectedIndexChanged(object sender, EventArgs e)
	{
		GridView1.PageIndex = 0;
	}

}

public class ListDataSource : IAutoFieldGenerator
{
	protected MetaTable _table;

	public ListDataSource(MetaTable table)
	{
		_table = table;
	}

	public ICollection GenerateFields(Control control)
	{
		List oFields = new List();

		foreach (MetaColumn col in _table.Columns)
		{
			if (col.Name == "Memo")
				continue;

			DynamicField f = new DynamicField()
			{
				DataField = col.Name
			};

			oFields.Add(f);
		}

		return oFields;
	}
}

Yes, the same works with DetailsView, except the property is named RowsGenerator instead of ColumnsGenerator.

David

As we loop though the fields, is there any way to mark a field as read-only?

foreach (MetaColumn col in _table.Columns)
{
	if (col.Name == "Memo")
		continue;

	DynamicField f = new DynamicField()
	{
		DataField = col.Name
	};

	oFields.Add(f);
}

I tried the updated line for the gridview, and several variations, and still get the same error.

-------------

Protected Sub Page_Init(ByVal sender As Object, ByVal e As EventArgs)
    DynamicDataManager1.RegisterControl(GridView1)
    Dim oLDS As New ListDataSource
    GridView1.ColumnsGenerator = oLDS
End Sub

 OK - I tried the updated code, but still get the same error - :( frustrating

 How do I manually add the update so intellisense will recognize it?  I am beginning to wonder if that is part of the problem.  I get build errors related to the dynamic stuff intellisense doesn't recognize.  Updated code below.

1    Imports Microsoft.VisualBasic
2    Imports System.Web
3    Imports System.Web.UI
4    Imports System.Web.DynamicData
5    Imports System.Collections.Generic
6    
7    
8    Public Class ListDataSource
9        Implements IAutoFieldGenerator
10   
11       Protected _table As MetaTable
12   
13       Public Sub New(ByVal table As MetaTable)
14           _table = table
15       End Sub
16   
17       Public Function GenerateFields(ByVal control As Control) As ICollection
18           Dim oFields = New List(Of DynamicField)
19           For Each col As MetaColumn In _table.Columns
20               If col.IsRequired Then
21                   Dim oDF As New DynamicField
22                   oDF.DataField = col.Name
23                   oFields.Add(oDF)
24               End If
25           Next
26           Return oFields
27       End Function
28   
29   End Class
30   
31   ------
32   
33   Imports System.Web.DynamicData
34   
35   Partial Class List
36       Inherits System.Web.UI.Page
37   
38       Protected table As MetaTable
39       
40       Protected Sub Page_Init(ByVal sender As Object, ByVal e As EventArgs)
41           DynamicDataManager1.RegisterControl(GridView1)
42       End Sub
43       
44       Protected Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)
45           table = GridDataSource.GetTable
46           Title = table.DisplayName
47           GridView1.ColumnsGenerator = New ListDataSource(table)
48           InsertHyperLink.NavigateUrl = table.GetActionPath(PageAction.Insert)
49           ' Disable various options if the table is readonly
50           If table.IsReadOnly Then
51               GridView1.Columns.RemoveAt(0)
52               InsertHyperLink.Visible = false
53           End If
54       End Sub
55       
56       Protected Sub OnFilterSelectedIndexChanged(ByVal sender As Object, ByVal e As EventArgs)
57           GridView1.PageIndex = 0
58       End Sub
59   
60   End Class
61