IFrame with no width/height fails

[daniel-hauser]

• You are using the latest version
• You are testing using the non-minified version of html2canvas and checked any potential issues reported in the console

Bug reports:

Trying to export an element with iframe with no width/height fails.

v1.0.0-rc.0: works as expected see here.
v1.0.0-rc.3: will fail with Failed to execute 'drawImage' on 'CanvasRenderingContext2D': The image argument is a canvas element with a width or height of 0. see here.

Specifications:

• html2canvas version tested with:
  • Browser & version: Google Chrome Version 74.0.3729.169 (Official Build) (64-bit)
  • Operating system: MacOS Mojave 10.14.5

[daniel-hauser]

#1887 is probably related but has no code to confirm

[daniel-hauser]

@niklasvh
A possible fix is to use getComputedStyle(iframe).width here instead of iframe.width (and same for height)

Would you want me to open a PR?

[val1984]

PR #1863 has been merged in master recently so next release will hopefully solve your issue.

[daniel-hauser]

The code added in #1863 will result in not adding the iframe to the canvas.
This is not good - as iframe width and height have default values (300 x 150px)

[val1984]

Sorry, I didn't check everything. You can definitely open a PR, that's what I did for the issue I had opened (#1865) and my PR has been merged.