Flaky IFrame Print Issue

[Mugs321]

Hey all,

Here's the deal... I have an iframe which I am using a to print a certain page without displaying said page. I've use this technique in other areas of my site and they work like a charm. Using the same code as all the other pages:

From page with print icon:

function printStudents(url1){
    objFrame = document.getElementById('printFrame');
    objFrame.src = url1;
    objFrame.focus();
}

From page (loaded in iframe) to be printed:

function doPrint(){
    this.focus();
    this.print();
}
document.onload=doPrint();

The iframe will not print when the icon is pressed though the function is being run (confirmed with an 'alert()'). HOWEVER, if I press my browser's 'Back' button then return to the page using 'Forward', the print dialog displays. It will also print if I load the iframe page in my browser normally.

Any thoughts?

[Mugs321]

Figured it out... guess it was a timing issue.

I added

document.onload=setTimeout("doPrint()", 100);

to the iframe page and it works fine now.

[Dasty]

Figured it out... guess it was a timing issue.

I added

document.onload=setTimeout("doPrint()", 100);

to the iframe page and it works fine now.

No, it is not ... it something different.

function doPrint(){
    this.focus();
    this.print();
}
document.onload=doPrint();

Look at your code closely. by doPrint(); you are calling doPrint function and you are storing result of this function into document.onload . So, you are not calling doPrint function after document is loaded as you would expect (which may cause issues as you described).

fix it that way:

function doPrint(){
    this.focus();
    this.print();
}
window.onload=doPrint;

Here, we are storing function reference into onload event as event handler which is now correctly fired after document is loaded. It's correct to use window.onload.

I would suggest to try this new code, because it's always risky to use timeout functions. It may work on your fast computer, but what if 100ms will be not enough for some users?

[Mugs321]

Dasty,
Your suggestion worked great. I am curious, however, as to why the script only executes properly when using window.onload (as opposed to document.onload )

[acoder]

Dasty,
Your suggestion worked great. I am curious, however, as to why the script only executes properly when using window.onload (as opposed to document.onload )

Use onload with the window object - see link.