sharepoint rendering templates set attributes from fields - asp.net

Question

I'm trying to write a custom rendering template for use in the DisplayForm of a list whose fields include Title, HeaderImageUrl, Body. I've got the following so far:
<SharePoint:RenderingTemplate ID="NewsListForm" runat="server">
<Template>
<h1><SharePoint:FieldValue FieldName="Title" runat="server"/></h1>
<div>
<p>
<SharePoint:UrlField FieldName="HeaderImageUrl" runat="server"></SharePoint:UrlField>
<SharePoint:RichTextField FieldName="Body" runat="server" />
</p>
</div>
</Template>
</SharePoint:RenderingTemplate>
The HeaderImageUrl field is configured to be an Image URL, but when I use the UrlField control, it renders a link.
I was thinking there might be a way to grab field values and put them in attributes, so something like this:
<asp:Image ImageUrl="<% FieldValue["HeaderImageUrl"] %>" runat="server"/>
If this kind of thing isn't possible, then is there another control in Microsoft.SharePoint.WebControls that would render an image from a URL?

Answer 1

All the examples I've seen of calling a URL field to be displayed as an image have been through C# code. Which is quite annoying since most of web part bits can be written without using C# code. You might also need to go down that road here... perhaps a custom field control or user control.
Even if your code above did get the value for HeaderImageUrl, it wouldn't work as Url values are (confusingly):
[the actual url specified][some wierd delimeter string][the description field of the url (usually the actual url again if your don't specify it)]
So you would need to split the string with te delimeter values and use the [0] (the first) as what you inject into your image url.
Please do post if you find a way to do this without writing C# code.
p.s. Have you considered using a DataFormWebPart which has a xsl section in which you might be able to do extractly what you need?!
Example: You can stick the following syntax into any aspx / ascx file:
<%# Register tagprefix="SharePoint" namespace="Microsoft.SharePoint.WebControls" assembly="Microsoft.SharePoint, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%# Register tagprefix="WebPartPages" namespace="Microsoft.SharePoint.WebPartPages" assembly="Microsoft.SharePoint, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<%# Register Tagprefix="PublishingWebControls" Namespace="Microsoft.SharePoint.Publishing.WebControls" Assembly="Microsoft.SharePoint.Publishing, Version=12.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c" %>
<WebPartPages:DataFormWebPart runat="server" IsIncluded="True" FrameType="None"
NoDefaultStyle="TRUE" ViewFlag="0" Title="My List Display"
Default="FALSE" ID="dfwp_MyListDisplay"
DisplayName="My List Display">
<DataSources>
<SharePoint:SPDataSource runat="server" DataSourceMode="List" UseInternalName="true"
selectcommand='<View><Query><Where><Eq><FieldRef Name="Category"/><Value Type="Text">Header</Value></Eq></Where></Query></View>' id="Utility_x0020_Navigation1"><SelectParameters><WebPartPages:DataFormParameter Name="ListName" ParameterKey="ListName" PropertyName="ParameterValues" DefaultValue="My List Display"/>
<asp:Parameter Name="ListName" DefaultValue="LIST NAME" />
<asp:Parameter Name="WebUrl" DefaultValue="<% $SPUrl:~SiteCollection/ %>" />
</SelectParameters>
</SharePoint:SPDataSource>
</DataSources>
<ParameterBindings>
<ParameterBinding Name="dvt_apos" Location="Postback;Connection"/>
<ParameterBinding Name="PageURL" Location="ServerVariable(URL)" DefaultValue=""/>
<ParameterBinding Name="SiteUrl" Location="ServerVariable(SERVER_NAME)" DefaultValue=""/>
</ParameterBindings>
<datafields>#Title,Title;#URL,URL;#Category,Category;#Parent_x0020_item,Parent_x0020_item;#Sort_x0020_Order,Sort Order;#ID,ID;#ContentType,Content Type;#Modified,Modified;#Created,Created;#Author,Created By;#Editor,Modified By;#_UIVersionString,Version;#Attachments,Attachments;#File_x0020_Type,File Type;#FileLeafRef,Name (for use in forms);#FileDirRef,Path;#FSObjType,Item Type;#_HasCopyDestinations,Has Copy Destinations;#_CopySource,Copy Source;#ContentTypeId,Content Type ID;#_ModerationStatus,Approval Status;#_UIVersion,UI Version;#Created_x0020_Date,Created;#FileRef,URL Path;</datafields>
<xsl>
YOUR XSLT HERE
</xsl>
</WebPartPages:DataFormWebPart>

Answer 2

The following code will get you the url of an imagefield:
SPListItem item = GetItem();
string imagefieldhtml = item["HeaderImageUrl"].ToString();
ImageFieldValue imagefield = new ImageFieldValue(imagefieldhtml);
var url = imagefield.ImageUrl;
So maybe altering your to something like this will help you, or maybe help you out atleast...?
<asp:Image ImageUrl="<% (ImageFieldValue ["HeaderImageUrl"]).ImageUrl %>" runat="server"/>

Answer 3

Unable to test it atm (no environment) but I am quite sure I did this before.
Try these:
<SharePoint:FieldValue FieldName="HeaderImageUrl" runat="server"/>
or:
<img src="<SharePoint:FieldValue FieldName="HeaderImageUrl" runat="server"/>" />
I'll check back on this one and do an actual test by monday if those didn't work and you still need help.

Answer 4

Turns out that my problem was simply that I didn't have that image column set up to render as an image, rather than as a link. The builtin Microsoft.SharePoint.UrlField control worked just fine, as it turned out.