Bug 177043

Summary:

innerWidth and innerHeight return 0 inside iframe created with document.write

Product:

WebKit

Reporter:

Matthias <MatthiasSaihttam1>

Component:

Frames

Assignee:

Nobody <webkit-unassigned>

Status:

NEW

Severity:

Normal

CC:

achristensen, ap, beidson, koivisto, simon.fraser, thorton

Priority:

Version:

WebKit Nightly Build

Hardware:

Unspecified

OS:

Unspecified

Attachments:

Description	Flags
A HTML file showing the bug.	none

Matthias

Reported 2017-09-16 18:48:59 PDT

Created attachment 321021 [details] A HTML file showing the bug. If you write to an iframe, innerWidth and innerHeight are 0 inside the iframe, even after the window "load" event fires. However, even 50ms later the dimensions are correct. This may be because the load event is fired too early, or because these properties are not set correctly. This behavior works as expected on other browsers (the width and height represent the dimensions of the iframe from the outset). Rather than try to explain the exact circumstances required to reproduce this, I'm going to include the following example which I used to confirm this issue (also attached). <!DOCTYPE HTML> <html> <body> <iframe src="about:blank" id="frame"></iframe> <script> var doc = document.getElementById("frame").contentDocument; doc.open(); doc.write(`<script> console.log("start", innerWidth); window.addEventListener("load", function () { console.log("onload", innerWidth); //Doesn't work. Prints 0 }); window.setTimeout(function () { console.log("50ms", innerWidth); //Works }, 50); </scr` + "ipt>"); doc.close(); </script> </body> </html>

Attachments
A HTML file showing the bug. (571 bytes, text/html) 2017-09-16 18:48 PDT, Matthias	no flags	Details
View All Add attachment proposed patch, testcase, etc.

Alexey Proskuryakov

Comment 1 2017-09-18 13:43:39 PDT

I think that this is probably more of an accidental implementation artifact of other browsers. The load event only means that subresources were loaded, not that layout is complete.

Matthias

Comment 2 2017-09-20 18:00:07 PDT

Thanks for that explanation, it helped me understand what's going on better. I tried the "DOMContentLoaded" event listener, but that didn't work. However, setTimeout(function, 0) did work, because that apparently pushes itself to the end of the command queue, after layout is done. It still seems counter-intuitive that the load listener fires before the layout is completed in this one case in this one browser, and that there's no official way to ensure layout is finished.

Simon Fraser (smfr)

Comment 3 2017-09-21 11:38:28 PDT

I would expect innerWidth to force a layout.

Note You need to log in before you can comment on or make changes to this bug.