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!
![Conquering Impostor Syndrome]()
Two years ago I documented my struggles with Imposter Syndrome and the response was immense. I received messages of support and commiseration from new web developers, veteran engineers, and even persons of all experience levels in other professions. I've even caught myself reading the post...
![9 Mind-Blowing Canvas Demos]()
The <canvas> element has been a revelation for the visual experts among our ranks. Canvas provides the means for incredible and efficient animations with the added bonus of no Flash; these developers can flash their awesome JavaScript skills instead. Here are nine unbelievable canvas demos that...
![Using jQuery and MooTools Together]()
There's yet another reason to master more than one JavaScript library: you can use some of them together! Since MooTools is prototype-based and jQuery is not, jQuery and MooTools may be used together on the same page.
The XHTML and JavaScript
jQuery is namespaced so the...
![Record Text Selections Using MooTools or jQuery AJAX]()
One technique I'm seeing more and more these days (CNNSI.com, for example) is AJAX recording of selected text. It makes sense -- if you detect users selecting the terms over and over again, you can probably assume your visitors are searching that term on Google...
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?