I made a macro which sets the Last-modified http header of Umbraco pages to Umbraco's @updateDate. This caches unmodified pages on the client side, which improves speed and reduces bandwidth on the server. I thought this might be interesting for others, or someone has an even better method?

Below is the basic pinciple. I did make a more advanced version that also takes the updateDate from childnodes, which are displayed as menu items on my pages - so these should also trigger a new Last-modified date. But for clearity, the below example is only for the current page:

The following msxsl:script part also belongs to the previeous answer but this fragment raised an error while posting in the forum. Insert this part in de above xslt while replaceing msxslscript by msxsl:script...

<msxslscript language="VB" implements-prefix="abc">
<msxsl:assembly name="System.Web"/>
<!-- assembly reference generates error while saving, so use Skip testing (ignore errors) - not ideal though... -->
<![CDATA[

public Function setModif(dat As String)
Dim mDat As DateTime = Convert.ToDateTime(dat).ToUniversalTime
System.Web.HttpContext.Current.Response.AddHeader("Last-modified", mDat.ToString("r"))
'Return mDat.ToString("r") 'use for debugging
Return ""
End Function

]]>

</msxslscript>

The following msxsl:script part also belongs to the previeous answer but this fragment raised an error while posting in the forum. Insert this part in de above xslt while replaceing msxslscript by msxsl:script and the same for msxsl:assambly...

<msxsl:script language="VB" implements-prefix="abc">
<msxsl:assembly name="System.Web"/>
<!-- assembly reference generates error while saving, so use Skip testing (ignore errors) - not ideal though... -->
<![CDATA[

public Func<!-- remove -->tion setModif(dat As String)
Dim mDat As DateTime = Convert.ToDateTime(dat).ToUniversalTime
System.Web.HttpContext.Current.Response.AddHeader("Last-modified", mDat.ToString("r"))
'Return mDat.ToString("r") 'use for debugging
Return ""
End Function

]]>

</msxsl:script>

And another try for the msxsl part... teh CDATA around the function raised the error while posting.

How do you mean? Using a user control macro instead of a xslt macro?

In that case, it's not so easy to get the @updateDate as it is in xslt.

And I do not like the viewstate en postback code to be inserted as ASPNET_HEAD does. (Thought ASPNET_HEAD isn't needed for a user control as long as no server controls are used in it.)

Or am I missing something? Is there an ASPNET_HEAD option that modifies http headers? I cannot see the relationship yet.