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Dynamic creation of columns

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Grid

This is a migrated thread and some comments may be shown as answers.

Arni Gunnar Ragnarsson asked on 09 Sep 2008, 09:12 AM

Hi all.

I am rewriting a rather large web application with just about 100 lists in it. We have to access control the lists, and the actions performed on them so we are trying to make the creation of the lists (RadGrids) dynamic.

In the old system, we would have a XML config file for the lists and then do the HTML by hand for each list.

We would like to continue using the XML file, and with regular GridBoundColumn types it works fine. We find ourselves in some problems when we need to display 2 field names in one column, then we have to use GridTemplateColumn.

With more than 100 lists, all with different datasources, things get a bit tricky. We have implemented a simple ITemplate for 1 datasource, but because all the datasources are different, this does not seem to be a viable solution. We would have to create an eventListener for all the special columns in all the datasources, with some very tricky coding ...

Is there any way we can send into the column collection a simple string like just like when we are creating a template column in the ASPX file:

<telerik:GridTemplateColumn>

<ItemTemplate>

<a href="<%#Eval("LinkUrl")%>"><%#Eval("LinkText")%></a>

</ItemTemplate>

</telerik:GridTemplateColumn>

Is it possible for us to use the <a href="<%#Eval("LinkUrl")%>"><%#Eval("LinkText")%></a> model to create these columns in any way ??

22 Answers, 1 is accepted

answered on 18 Dec 2008, 01:07 PM

WebSite1.zip

Hello Rob,

Please try the attached sample and let me know if it works as desired and what differs in your case. If you could modify the sent code so the issue is replicable and turn it, this can help us find a resolution for you.

Kind regards,
Iana
the Telerik team

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answered on 16 Jun 2009, 06:06 AM

While there are some tantalizing hints in the references you provide, I don't see a direct answer to the question posed by Arni Gunnar Ragnarsson: is it possible to include <% # Eval("FieldName") %> dynamically in an ItemTemplate?

I'm using a RadGrid in MVC, where there are no postbacks, and I'd like to generate GridTemplateColumns like the one below dynamically in client-side script. Is this possible?

<telerik:GridTemplateColumn>

# Ajax.ActionLink("Column1", "Sort", new { columnName = "Column1" }, options)%>

</HeaderTemplate>

# Eval("Column1")%>

</ItemTemplate>

# Html.TextBox("Column1", Eval("Column1").ToString())%>

</EditItemTemplate>

</telerik:GridTemplateColumn>

Frank

answered on 02 Jul 2009, 07:24 PM

iana -

per a previos your post of yours regarding the error "Cannot create column with the specified type name: GridCalculatedColumn":

"Hi Rob,

I followed your scenario and was able to replicate the issue. It seems that there is a problem with the ViewState of the calculated column when it is created at runtime. I forwarded the issue for further investigation and testing and hope it could be fixed soon.

As a workaround, I suggest that you set the EnableColumnsViewState property of the MasterTableView to false and create your columns on Page.Init or on each Page.Load.

Give it a try and let me know if this works for you."

i am also trying to dynamically create a radgrid with a calculated column and am getting the same error as rob was. has this been fixed?

my calculated column is in the markup, but i assign the DataFields and Expression property in the codebehind since the gridboundcolumns are dynamically generated. here is my code:

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

        protected void InitPage()
        {
            ddlDestinations.FillWithEntity((new DestinationProxy()).GetAllDestinations(), true);

int n = ScrapTypes.Length;

string[] DataFields = new string[n];
string[] Expression = new string[n];

            for (int i = 0; i < n; i++)
            {
                ScrapType ScrapType = ScrapTypes[i];

                string ScrapTypeName = StripIt(ScrapType.Name);
                string EditorId = "Editor" + ScrapTypeName;
                GridEditableColumn col = new GridBoundColumn();
                GridTemplateColumnEditor Editor = new GridTemplateColumnEditor();

                rgCalendar.Columns.Add(col);
                phEditors.Controls.Add(Editor);

                //i build the GridCalculatedColumn properties here

DataFields[i] = ScrapTypeName;
Expression[i] = "{" + i.ToString() + "}";

                ((GridBoundColumn)col).DataField = ScrapTypeName;
                ((GridBoundColumn)col).Aggregate = GridAggregateFunction.Sum;
                ((GridBoundColumn)col).DataType = typeof(int);
                col.UniqueName = ScrapTypeName;
                col.HeaderText = ScrapType.Name;
                col.ColumnEditorID = EditorId;
                col.ItemStyle.Width = Unit.Pixel(100);
                col.ItemStyle.Wrap = false;

Editor.ID = EditorId;
}

GridCalculatedColumn Calc = (GridCalculatedColumn)rgCalendar.Columns.FindByUniqueName("ItemTotal");

            //here is where i assign those property values
            Calc.Expression = string.Join("+", Expression);
            Calc.DataFields = DataFields.ToArray();

rgCalendar.MasterTableView.SwapColumns("ItemTotal", StripIt(ScrapTypes[ScrapTypes.Length - 1].Name));
}

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

you previously recommended to another user that they disable viewstate, but this will affect being able to extract values from the grideditcolumns.

dynamic radgrid building has been an experience indeed. is there a resolution to this issue?

answered on 24 Mar 2010, 03:33 PM

calculatedcolumn.zip

Hi Chris,

Indeed, the issue should be fixed in the current version of RadControls for ASP.NET AJAX.
Please check the attached working sample and let me know if something differs in your case and is any issues arise.

Regards,
Iana
the Telerik team

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