Question

I am wiring a startup script JavaScript function on Page_Load to fire like so:

ScriptManager.RegisterStartupScript(Me, GetType(Page), "page_init", "page_init();", True)

This function calls a couple of different functions to setup the page. One of those functions checks the document.readyState and makes sure it’s "complete". This deals with images and I want to make sure everything has been fully rendered.

if (document.readyState == "complete") {

Everything works fine, until I need to write a byte array to the outputstream (using either Response.BinaryWrite or Response.OutputStream.Write() to give a file to a user. After that, the document.readyState is always “interactive”, until I navigate off of the page and back. I have even used a setTimeout(myFunction, 1000); call if document.readyState isn’t complete to recursively call the function until it is complete. It never reaches “complete”.

I have researched this myself for quite sometime, and cannot figure out this behavior. Any ideas as to how this is happening?

Answer 1

I just found out the issue is with an IFrame, which I apologize was a detail left out of the question.

More information can be found here:

IE (surprisingly gets my vote of
approval here) There is an
onreadystatechange event that fires
whenever the iFrame’s readyState
property changes. That readyState
reflects where the download is in the
process.

Inline: When you initially set the src
value of the iFrame element, the
readyState changes to loading. When
the file has completely downloaded,
the readyState changes to interactive.
The big difference between IE and the
other browsers is that IE then changes
the readyState property to complete
when the page (or application) is
fully loaded and ready for the user.

Attachment: This behaves identically
to the Inline case of IE, but the
readyState property never changes to
complete. That wouldn’t make much
sense, since the user has to manually
open the file by double-clicking on it
or opening it from some application.