How do I fetch the attachments from an AttachmentsField control?

Question

In WSS 3.0, I've got an edit form which includes an AttachmentsField control. It corresponds to the list of existing attachments, with delete links. In a normal edit form, if you delete an attachment and hit Save, it'll then remove the attachment.

I want to replicate this functionality for something similar, but I'm unsure how to extract the current list of attachments stored in the control. I need to do this in order to reflect any changes based on that.

The Value property of the AttachmentsField is apparently null, whether or not there are any attachments and whether or not I've made any changes on the control. If I check AttachmentsField.Controls and recursively loop through it, there's a Literal in it with an ID of AttachmentsList, but I'm not sure how to extract the data from it (it errors if I try to print its Text property). I can't find any other avenues of entry to try and access the data.

How do I extract the list of attachments currently rendered in the AttachmentsField control?

Answer 1

I had a glance in the AttachmentsField.UpdateFieldValueInItem call to see where it gets the list of files from for its own use.

It appears to use this property: AttachmentsField.Context.Request.Files, the documentation for which is here:

HttpRequest.Files

Edit: I suddenly realised that you may be trying to access the control in order to save the attachments. If that's the case then AttachmentsField.UpdateFieldValueInItem is in itself the answer. :)

Answer 2

Looking at a custom EditForm.aspx page in Sharepoint Designer, the form code looks like this:

<tr id="idAttachmentsRow">
 <td nowrap="true" valign="top" class="ms-formlabel" width="20%">
  <SharePoint:FieldLabel ControlMode="Edit" FieldName="Attachments" runat="server"/>
 </td>
 <td valign="top" class="ms-formbody" width="80%">
  <SharePoint:FormField runat="server" id="AttachmentsField" ControlMode="Edit" FieldName="Attachments" __designer:bind="{ddwrt:DataBind('u','AttachmentsField','Value','ValueChanged','ID',ddwrt:EscapeDelims(string(@ID)),'@Attachments')}"/>
   <script>
      var elm = document.getElementById("idAttachmentsTable");
      if (elm == null || elm.rows.length == 0)
      document.getElementById("idAttachmentsRow").style.display='none';
   </script>
 </td>
</tr>

Wouldn't you want to mimmic that code?

Edit: Attaching a file to a list item results in default EditForm code like this:

<TABLE border=0 cellpadding=0 cellspacing=0 id=idAttachmentsTable>
            <TR id={7D99341E-8DFE-4EC1-83E9-46B1AAECFA71}><TD class="ms-vb"><span dir="ltr"><a tabindex=1 onclick="DispDocItemEx(this, 'FALSE', 'FALSE', 'FALSE', 'SharePoint.OpenDocuments.3')" href="https://my.domain.com/sites/spsite/Lists/Calendar/Attachments/3/features.xls">features.xls</a></span>&nbsp;&nbsp;&nbsp;&nbsp;</TD><TD class="ms-propertysheet"><IMG alt='Delete' SRC="/_layouts/images/rect.gif">&nbsp;<a tabindex=1 href="javascript:RemoveAttachmentFromServer('{7D99341E-8DFE-4EC1-83E9-46B1AAECFA71}',1)">Delete</a></TD></TR>
        </TABLE>

What do you want to do with the files?

Answer 3

If I understood your question correctly you want to retrieve the list of attachments of current list item in server-side code. In such a case there is Attachments property of SPListItem.