add excludeFromExport property (#2976)

* add excludeFromExport property
* added test for SVG and JSON

src/shapes/object.class.js

@@ -744,6 +744,16 @@
      */
 
     lockScalingFlip:          false,
+
+    /**
+     * When `true`, object is not exported in SVG or OBJECT/JSON
+     * since 1.6.3
+     * @type Boolean
+     * @default
+     */
+
+    excludeFromExport:          false,
+
     /**
      * List of properties to consider when checking if state
      * of an object is changed (fabric.Object#hasStateChanged)

src/static_canvas.class.js

@@ -1073,9 +1073,11 @@
      * @private
      */
     _toObjects: function(methodName, propertiesToInclude) {
-      return this.getObjects().map(function(instance) {
-        return this._toObject(instance, methodName, propertiesToInclude);
-      }, this);
+      return this.getObjects().filter(function(object) {
+          return !object.excludeFromExport;
+        }).map(function(instance) {
+          return this._toObject(instance, methodName, propertiesToInclude);
+        }, this);
     },
 
     /**
@@ -1296,11 +1298,15 @@
      * @private
      */
     _setSVGObjects: function(markup, reviver) {
+      var instance, originalProperties;
       for (var i = 0, objects = this.getObjects(), len = objects.length; i < len; i++) {
-        var instance = objects[i],
-            //If the object is in a selection group, simulate what would happen to that
-            //object when the group is deselected
-            originalProperties = this._realizeGroupTransformOnObject(instance);
+        instance = objects[i];
+        if (instance.excludeFromExport) {
+          continue;
+        }
+        //If the object is in a selection group, simulate what would happen to that
+        //object when the group is deselected
+        originalProperties = this._realizeGroupTransformOnObject(instance);
         markup.push(instance.toSVG(reviver));
         this._unwindGroupTransformOnObject(instance, originalProperties);
       }

test/unit/canvas_static.js

@@ -586,6 +586,80 @@
     canvas.renderOnAddRemove = true;
   });
 
+  test('toSVG with reviver', function() {
+    ok(typeof canvas.toSVG == 'function');
+    canvas.clear();
+
+    var circle = new fabric.Circle(),
+        rect = new fabric.Rect(),
+        path1 = new fabric.Path('M 100 100 L 300 100 L 200 300 z'),
+        tria = new fabric.Triangle(),
+        polygon = new fabric.Polygon([{x: 10, y: 12},{x: 20, y: 22}]),
+        polyline = new fabric.Polyline([{x: 10, y: 12},{x: 20, y: 22}]),
+        line = new fabric.Line(),
+        text = new fabric.Text('Text'),
+        group = new fabric.Group([text, line]),
+        ellipse = new fabric.Ellipse(),
+        image = new fabric.Image({width: 0, height: 0}),
+        imageBG = new fabric.Image({width: 0, height: 0}),
+        imageOL = new fabric.Image({width: 0, height: 0}),
+        path2 = new fabric.Path('M 0 0 L 200 100 L 200 300 z'),
+        path3 = new fabric.Path('M 50 50 L 100 300 L 400 400 z'),
+        pathGroup = new fabric.PathGroup([path2, path3]);
+
+    canvas.renderOnAddRemove = false;
+    canvas.add(circle, rect, path1, tria, polygon, polyline, group, ellipse, image, pathGroup);
+    canvas.setBackgroundImage(imageBG);
+    canvas.setOverlayImage(imageOL);
+    var reviverCount = 0,
+        len = canvas.size() + group.size() + pathGroup.paths.length;
+
+    function reviver(svg) {
+      reviverCount++;
+      return svg;
+    }
+
+    canvas.toSVG(null, reviver);
+    equal(reviverCount, len + 2, 'reviver should include background and overlay image');
+    canvas.setBackgroundImage(null);
+    canvas.setOverlayImage(null);
+    canvas.renderOnAddRemove = true;
+  });
+
+  test('toSVG with exclude from export', function() {
+    ok(typeof canvas.toSVG == 'function');
+    canvas.clear();
+
+    var circle = new fabric.Circle({excludeFromExport: true}),
+        rect = new fabric.Rect({excludeFromExport: true}),
+        path1 = new fabric.Path('M 100 100 L 300 100 L 200 300 z'),
+        tria = new fabric.Triangle(),
+        polygon = new fabric.Polygon([{x: 10, y: 12},{x: 20, y: 22}]),
+        polyline = new fabric.Polyline([{x: 10, y: 12},{x: 20, y: 22}]),
+        line = new fabric.Line(),
+        text = new fabric.Text('Text'),
+        group = new fabric.Group([text, line]),
+        ellipse = new fabric.Ellipse(),
+        image = new fabric.Image({width: 0, height: 0}),
+        path2 = new fabric.Path('M 0 0 L 200 100 L 200 300 z'),
+        path3 = new fabric.Path('M 50 50 L 100 300 L 400 400 z'),
+        pathGroup = new fabric.PathGroup([path2, path3]);
+
+    canvas.renderOnAddRemove = false;
+    canvas.add(circle, rect, path1, tria, polygon, polyline, group, ellipse, image, pathGroup);
+    var reviverCount = 0,
+        len = canvas.size() + group.size() + pathGroup.paths.length;
+
+    function reviver(svg) {
+      reviverCount++;
+      return svg;
+    }
+
+    canvas.toSVG(null, reviver);
+    equal(reviverCount, len - 2, 'reviver should not include objects with excludeFromExport');
+    canvas.renderOnAddRemove = true;
+  });
+
   test('toJSON', function() {
     ok(typeof canvas.toJSON == 'function');
     equal(JSON.stringify(canvas.toJSON()), '{"objects":[],"background":""}');
@@ -668,6 +742,17 @@
     equal(canvas.toObject().objects[0].type, rect.type);
   });
 
+  test('toObject excludeFromExport', function() {
+    var rect = makeRect(), rect2 = makeRect(), rect3 = makeRect();
+    canvas.clear();
+    canvas.add(rect, rect2, rect3);
+    equal(canvas.toObject().objects.length, 3, 'all objects get exported');
+    rect.excludeFromExport = true;
+    rect2.excludeFromExport = true;
+    equal(canvas.toObject().objects.length, 1, 'only one object gets exported');
+  });
+
+
   test('toDatalessObject', function() {
     ok(typeof canvas.toDatalessObject == 'function');
     var expectedObject = {