SharePoint 2010 Script On Demand–give me my scripts right now!

Hi all! May be you are already familiar with sharepoint 2010 script on demand feature. Recently I was playing with it and want to show some examples and explanations how it works.

There is a server control, that is responsible for rendering scripts on demand - ScriptLink .This control has 4 significant properties: LoadAfterUI, Name, OnDemand and Localizable.

  • LoadAfterUI (if true) means that your script link (or script) will be rendered at the vary end of the <form> tag (when all other html elements already loaded). if this property equals to false, script will be inserted right after <form> tag. Internally, methods RegisterStartupScript and RegisterClientScriptBlock used. The only difference between these two methods is where each one emits the script block. RegisterClientScriptBlock() emits the script block at the beginning of the Web Form (right after the <form runat="server"> tag), while RegisterStartupScript() emits the script block at the end of the Web Form (right before the </form> tag).
  • Name - name of script file (or path to that file – read below). This property uses by javascript as key that uniquely identify loaded script.
  • Localizable – if true, sharepoint try to find your script under “_layouts/1033/”
  • OnDemand – the most interesting property, indicates if we need this script load immediately, or if it should be downloaded on demand

Ok, some examples. Imagine we have script file myscript.js directly inside the layouts folder and we want to load it (OnDemand = false) . Its easy:

<SharePoint:ScriptLink runat="server" ID="sl" Localizable="False" LoadAfterUI="False" Name="myscript" OnDemand="False"></SharePoint:ScriptLink>

This action produces this output:

<script src="/_layouts/myscript.js?rev=7KqI9%2FoL9hClomz1RdzTqg%3D%3D" type="text/javascript"></script>