Added Canvas#toDataURL()

lib/buffer.js

@@ -0,0 +1,22 @@
+
+/*!
+ * Canvas - Buffer
+ * Copyright (c) 2010 LearnBoost <tj@learnboost.com>
+ * MIT Licensed
+ */
+
+/**
+ * Concatenate `this` Buffer with `buf`.
+ *
+ * @param {Buffer} buf
+ * @return {Buffer}
+ * @api public
+ */
+
+Buffer.prototype.concat = function(buf) {
+  var len = this.length
+    , tmp = new Buffer(len + buf.length);
+  this.copy(tmp, 0, 0);
+  buf.copy(tmp, len, 0);
+  return tmp;
+};

lib/canvas.js

@@ -41,6 +41,12 @@ exports.cairoVersion = cairoVersion;
 
 var cache = {};
 
+/**
+ * Buffer extensions.
+ */
+
+require('./buffer');
+
 /**
  * Return a function used to normalize an RGBA color `prop`.
  *
@@ -168,6 +174,35 @@ Canvas.prototype.createPNGStream = function(){
   return new PNGStream(this);
 };
 
+Canvas.prototype.toBuffer = function(){
+  var buf;
+  this.streamPNG(function(err, chunk, len){
+    if (err) throw err;
+    if (len) {
+      buf = buf
+        ? buf.concat(chunk)
+        : chunk;
+    }
+  });
+  return buf;
+};
+
+/**
+ * Return a data url.
+ *
+ * @param {String} type
+ * @return {String}
+ * @api public
+ */
+
+Canvas.prototype.toDataURL = function(type){
+  // TODO: jpeg / svg
+  type = type || 'image/png';
+  if ('image/png' != type) throw new Error('currently only image/png is supported');
+  return 'data:' + type
+    + ';base64,' + this.toBuffer().toString('base64');
+};
+
 /**
  * Add `color` stop at the given `offset`.
  *

test/canvas.test.js

@@ -550,6 +550,28 @@ module.exports = {
     assert.ok(!ctx.isPointInPath(50,120));
   },
   
+  'test #toDataURL()': function(assert){
+    var canvas = new Canvas(200, 200)
+      , ctx = canvas.getContext('2d');
+
+    ctx.fillRect(0,0,100,100);
+    ctx.fillStyle = 'red';
+    ctx.fillRect(100,0,100,100);
+
+    var str = 'data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAMgAAADICAYA'
+      + 'AACtWK6eAAAABmJLR0QA/wD/AP+gvaeTAAABbElEQVR4nO3TQQ0AMQwDwVz5c+4x2'
+      + 'G/zmEFgydpvZu6whjN2Oa8HwGYCgSAQCAKBIBAIAoEgEAgCgSAQCAKBIBAIAoEgEA'
+      + 'gCgSAQCAKBIBAIAoEgEAgCgSAQCAKBIBAIAoEgEAgCgSAQCAKBIBAIAoEgEAgCgSA'
+      + 'QCAKBIBAIAoEgEAgCgSAQCAKBIBAIAoEgEAgCgSAQCAKBIBAIAoEgEAgCgSAQCAKBI'
+      + 'BAIAoEgEAgCgSAQCAKBIBAIAoEgEAgCgSAQCAKBIBAIAoEgEAgCgSAQCAKBIBAIAoEg'
+      + 'EAgCgSAQCAKBIBAIAoEgEAgCgSAQCAKBIBAIAoEgEAgCgSAQCAKBIBAIAoEgEAgCgSAQ'
+      + 'CAKBIBAIAoEgEAgCgSAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA'
+      + 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACAhX5bnALGvZc/ggA'
+      + 'AAABJRU5ErkJggg==';
+    
+    assert.equal(str, canvas.toDataURL(), 'Canvas#toDataURL() failed');
+  },
+  
   'test PNGStream': function(assert, beforeExit){
     var canvas = new Canvas(320, 320)
       , ctx = canvas.getContext('2d')