Update the current strokes state after erasing

[rmsandu]

When using the erase button the line would be erased visually, but it wouldn't remove the respective strokes from the array. The equiv function seems to be outdated and the comparison fails.

If saving of the strokes (offline raster image) is wanted (with RaphaelExport, canvg) this update will render the correct strokes.

[cecilpeng]

the right solution is to protect the data format of the stored strokes. It is broken after having called sketchpad.json(). Please use var _strokes_copy = jQuery.extend(true, [], _strokes_copy, _strokes); instead.

self.json = function(value) {
            if (value === undefined) {
                var _strokes_copy = jQuery.extend(true, [], _strokes_copy, _strokes);
                for (var i = 0, n = _strokes_copy.length; i < n; i++) {
                    var stroke = _strokes_copy[i];
                    if (typeof stroke.path == "object") {
                        stroke.path = svg_path_to_string(stroke.path);
                    }
                }
                return JSON.stringify(_strokes_copy);
            }

            return self.strokes(JSON.parse(value));
        };

[rmsandu]

@cecilpeng thanks for your solution. can you show me the exact bug? I can updated it in the pull request then....anyways I feel OP is not updating this repository anymore. Feel free to check out my version of it, based on the same website : https://github.com/raluca-san/IAT-image-annotation-website