Sitecore Field Renderer - add markup inside rendering

Question

As part of an SEO enhancement project, I've been tasked with adding the following property inside the markup for the image that the field renderer is generating on the page:

itemprop="contentURL" - before the closing tag.

<sc:FieldRenderer ID='FieldRenderer_MainImage' Runat='server' FieldName='Homepage Image'
    CssClass="_image" Parameters="w=150" itemprop="contentURL" />

When I tried to place this inside the Field Renderer, or add it as a "parameter" - it doesn't work.

Is there another way to do this, without having to create a control file and generate the output in the code-behind?

Answer 1

You need to use the "Parameters" property for setting extra properties on both the and control.

You can to it like this :

<sc:FieldRenderer ID="PageImage" runat="server" FieldName="ContentImage" Parameters="ControlType=C4Image&rel=relString" />
<sc:Image ID="SCPageImage" runat="server" Field="ContentImage" Parameters="ControlType=C4Image&rel=relString" />

That will be rendered like this :

<img width="1232" height="637" controltype="C4Image" rel="relString" alt="" src="~/media/Images/DEMO backgrounds/background2.ashx">

Note: This works in 6.5 and 6.6 - not sure which version is being used in this question.

Answer 2

Couldn't this be done by extending the RenderField pipeline? You could potentially decompile (using Reflector or ILSpy) the GetImageFieldValue and add your own logic to adjust the output from the ImageRenderer?

Reference Sitecore.Pipelines.RenderField.GetImageFieldValue.