HtmlEditor does not show toolbar images when EnablePartialRendering=true

[andrewchilcott]

The AJAX Control Toolkit \16.1.1

The installation method

• Installer

Minimal steps to reproduce the bug

Add an HtmlEditorExtender to a TextBox in the EditItemTemplate of a ListView inside an UpdatePanel inside an ascx UserControl inside an aspx page using site.Master.

Within the site.Master file an asp:ScriptManager is loaded

Actual result

When ScriptManager EnablePartialRendering = true then the control appears without any images on the buttons.

Expected result

When ScriptManager EnablePartialRendering = false then the control appears with images on the buttons.

Browser(s) used

A site deployment method

• VS development web-server,

Obviously, turning partial rendering off is not what I want to do. I want the control to work with partial rendering of the page.

I understand from lots of old postings from a Google search that this was a known problem over several years. I could not find a resolution. Was this one of the bugs that was addressed when DevExpress took over the code maintenance? If so, what is the solution?

Andrew Chilcott

[MikhailTymchukDX]

Hi @andrewchilcott,
 
I would like to thank you for bringing such an interesting issue to our attention. It was not addressed earlier, because we didn't test such CSS-rich control inside an UpdatePanel.
 
This bug comes from the way toolkit registers CSS links for a control.
 
When there is no UpdatePanel or EnablePartialRendering = false the links to CSS resources are injected into the code via server code: https://github.com/DevExpress/AjaxControlToolkit/blob/master/AjaxControlToolkit/ToolkitResourceManager.cs#L203-L208
 
However, when an async postback arrives from an UpdatePanel, these links are rendered inside the UpdatePanel's DOM using the client script: https://github.com/DevExpress/AjaxControlToolkit/blob/master/AjaxControlToolkit/ToolkitResourceManager.cs#L221-L235
 
We cannot suggest any workaround for this issue, but the fix is underway.