pageLoad() and ready()

If ever wondered the difference between .ready() abd pageLoad() in JQuery and ASP.NET AJAX frameworks, here is the gist.

$(document).ready()

  • Ideal for onetime initialization.
  • Optimization black magic; may run slightly earlier than pageLoad().
  • Does not re-attach functionality to elements affected by partial postbacks.

pageLoad()

  • Unsuitable for onetime initialization if used with UpdatePanels.
  • Slightly less optimized in some browsers, but consistent.
  • Perfect for re-attaching functionality to elements within UpdatePanels.

Application.Init

  • Useful for onetime initialization if only ASP.NET AJAX is available.
  • More work required to wire the event up.
  • Exposes you to the “sys is undefined” error if you aren’t careful.