Cross Domain Canvas Images
You can do some really awesome stuff with images when you push their data into canvas. And of course, when you're done playing around with the image, you can export the canvas data to an IMG element and data URI. What we sometimes don't remember, however, is that the cross-origin rules apply to those images, so if you try to convert an image from another host to canvas, you'll get an error. You can use this snippet from HTML5 Boilerplate within the image host domain's .htaccess file to allow cross-origin data reading of images:
<IfModule mod_setenvif.c>
<IfModule mod_headers.c>
<FilesMatch "\.(cur|gif|ico|jpe?g|png|svgz?|webp)$">
SetEnvIf Origin ":" IS_CORS
Header set Access-Control-Allow-Origin "*" env=IS_CORS
</FilesMatch>
</IfModule>
</IfModule>
Allowing for CORS within .htaccess then allows you to pull image data when the image is on another domain. This is especially useful on CDNs! .htaccess is a life-saver sometimes!
![5 Awesome New Mozilla Technologies You’ve Never Heard Of]()
My trip to Mozilla Summit 2013 was incredible. I've spent so much time focusing on my project that I had lost sight of all of the great work Mozillians were putting out. MozSummit provided the perfect reminder of how brilliant my colleagues are and how much...
![7 Essential JavaScript Functions]()
I remember the early days of JavaScript where you needed a simple function for just about everything because the browser vendors implemented features differently, and not just edge features, basic features, like addEventListener and attachEvent. Times have changed but there are still a few functions each developer should...
![MooTools Link Fading]()
We all know that we can set a different link color (among other properties) on the hover event, but why not show a little bit more dynamism by making the original color fade to the next? Using MooTools 1.2, you can achieve that effect.
The MooTools...
![pointer Media Query]()
As more devices emerge and differences in device interaction are implemented, the more important good CSS code will become. In order to write good CSS, we need some indicator about device capabilities. We've used CSS media queries thus far, with checks for max-width and pixel ratios.
I’m finding that I get CORS errors when I request from my own site and then convert them to base64 images using the “canvas technique” referred to here. Is that expected?