I'm writing a chrome extension which does the following:
- Downloads a file from a website to memory using
XMLHttpRequest
- Adds additional data to the file and then base64 encodes the result to the variable
total_encoded_data
- Offers the data to the user using
<a href=data:application/octet-stream;charset=utf-8;base64,' + total_encoded_data+' download='file.bin'>Click to Download</a>
. Wheretotal_encoded_data
is added to href using jQuery.
I have found, through a manual binary search, that if the size of total_encoded_data
is greater than 2097100 characters, then I will get an Aw, Snap message when I click the link. If the size is smaller, then I can download as expected.
In addition to testing the filesize, I also used atoi
to ensure that the base64 encoding is valid, and it operates without error.
The Aw, Snap messages don't produce any crash reports in chrome://crashes
nor any unexpected output in the chrome_debug.log
How do I avoid an Aw, Snap message when serving a data uri where the base64 encoded string length is greater than 2097100?
It's a known chromium bug. The recommended workaround is to use a blob URL. Also see Creating a Blob from a base64 string in JavaScript.