Subversion Repositories munaweb

/**

 * Converts an image to a dataURL

 * @param  {String}   src          The src of the image

 * @param  {Function} callback

 * @param  {String}   outputFormat [outputFormat='image/png']

 * @url   https://gist.github.com/HaNdTriX/7704632/

 * @docs  https://developer.mozilla.org/en-US/docs/Web/API/HTMLCanvasElement#Methods

 * @author HaNdTriX

 * @example

 *

 *   toDataUrl('http://goo.gl/AOxHAL', function(base64Img){

 *     console.log('IMAGE:',base64Img);

 *   })

 *

 */

function toDataUrl(src, callback, outputFormat) {

  // Create an Image object

  var img = new Image();

  // Add CORS approval to prevent a tainted canvas

  img.crossOrigin = 'Anonymous';

  img.onload = function() {

    // Create an html canvas element

    var canvas = document.createElement('CANVAS');

    // Create a 2d context

    var ctx = canvas.getContext('2d');

    var dataURL;

    // Resize the canavas to the original image dimensions

    canvas.height = this.naturalHeight;

    canvas.width = this.naturalWidth;

    // Draw the image to a canvas

    ctx.drawImage(this, 0, 0);

    // Convert the canvas to a data url

    dataURL = canvas.toDataURL(outputFormat);

    // Return the data url via callback

    callback(dataURL);

    // Mark the canvas to be ready for garbage

    // collection

    canvas = null;

  };

  // Load the image

  img.src = src;

  // make sure the load event fires for cached images too

  if (img.complete || img.complete === undefined) {

    // Flush cache

    img.src = 'data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///ywAAAAAAQABAAACAUwAOw==';

    // Try again

    img.src = src;

  }

}