JSON Patch duplex - ignore locally added properties

json-patch-duplex.js

// json-patch-duplex.js 0.3.6 with enhancement to ignore locally added properties
// (c) 2013 Joachim Wester
// MIT license
var jsonpatch;
(function (jsonpatch) {
    var objOps = {
        add: function (obj, key) {
            obj[key] = this.value;
            return true;
        },
        remove: function (obj, key) {
            delete obj[key];
            return true;
        },
        replace: function (obj, key) {
            obj[key] = this.value;
            return true;
        },
        move: function (obj, key, tree) {
            var temp = { op: "_get", path: this.from };
            apply(tree, [temp]);
            apply(tree, [
                { op: "remove", path: this.from }
            ]);
            apply(tree, [
                { op: "add", path: this.path, value: temp.value }
            ]);
            return true;
        },
        copy: function (obj, key, tree) {
            var temp = { op: "_get", path: this.from };
            apply(tree, [temp]);
            apply(tree, [
                { op: "add", path: this.path, value: temp.value }
            ]);
            return true;
        },
        test: function (obj, key) {
            return (JSON.stringify(obj[key]) === JSON.stringify(this.value));
        },
        _get: function (obj, key) {
            this.value = obj[key];
        }
    };

    var arrOps = {
        add: function (arr, i) {
            arr.splice(i, 0, this.value);
            return true;
        },
        remove: function (arr, i) {
            arr.splice(i, 1);
            return true;
        },
        replace: function (arr, i) {
            arr[i] = this.value;
            return true;
        },
        move: objOps.move,
        copy: objOps.copy,
        test: objOps.test,
        _get: objOps._get
    };

    var observeOps = {
        add: function (patches, path) {
            var patch = {
                op: "add",
                path: path + escapePathComponent(this.name),
                value: this.object[this.name]
            };
            patches.push(patch);
        },
        'delete': function (patches, path) {
            var patch = {
                op: "remove",
                path: path + escapePathComponent(this.name)
            };
            patches.push(patch);
        },
        update: function (patches, path) {
            var patch = {
                op: "replace",
                path: path + escapePathComponent(this.name),
                value: this.object[this.name]
            };
            patches.push(patch);
        }
    };

    function escapePathComponent(str) {
        if (str.indexOf('/') === -1 && str.indexOf('~') === -1)
            return str;
        return str.replace(/~/g, '~0').replace(/\//g, '~1');
    }

    function _getPathRecursive(root, obj) {
        var found;
        for (var key in root) {
            if (root.hasOwnProperty(key)) {
                if (root[key] === obj) {
                    return escapePathComponent(key) + '/';
                } else if (typeof root[key] === 'object') {
                    found = _getPathRecursive(root[key], obj);
                    if (found != '') {
                        return escapePathComponent(key) + '/' + found;
                    }
                }
            }
        }
        return '';
    }

    function getPath(root, obj) {
        if (root === obj) {
            return '/';
        }
        var path = _getPathRecursive(root, obj);
        if (path === '') {
            throw new Error("Object not found in root");
        }
        return '/' + path;
    }

    var beforeDict = [];

    jsonpatch.intervals;

    var Mirror = (function () {
        function Mirror(obj) {
            this.observers = [];
            this.obj = obj;
        }
        return Mirror;
    })();

    var ObserverInfo = (function () {
        function ObserverInfo(callback, observer) {
            this.callback = callback;
            this.observer = observer;
        }
        return ObserverInfo;
    })();

    function getMirror(obj) {
        for (var i = 0, ilen = beforeDict.length; i < ilen; i++) {
            if (beforeDict[i].obj === obj) {
                return beforeDict[i];
            }
        }
    }

    function getObserverFromMirror(mirror, callback) {
        for (var j = 0, jlen = mirror.observers.length; j < jlen; j++) {
            if (mirror.observers[j].callback === callback) {
                return mirror.observers[j].observer;
            }
        }
    }

    function removeObserverFromMirror(mirror, observer) {
        for (var j = 0, jlen = mirror.observers.length; j < jlen; j++) {
            if (mirror.observers[j].observer === observer) {
                mirror.observers.splice(j, 1);
                return;
            }
        }
    }

    function unobserve(root, observer) {
        generate(observer);
        if (Object.observe) {
            _unobserve(observer, root);
        } else {
            clearTimeout(observer.next);
        }

        var mirror = getMirror(root);
        removeObserverFromMirror(mirror, observer);
    }
    jsonpatch.unobserve = unobserve;

    var privateProperties = new WeakMap();

    function observe(obj, callback) {
        var patches = [];
        var root = obj;
        var observer;
        var mirror = getMirror(obj);

        if (!mirror) {
            mirror = new Mirror(obj);
            beforeDict.push(mirror);
        } else {
            observer = getObserverFromMirror(mirror, callback);
        }

        if (observer) {
            return observer;
        }

        if (Object.observe) {
            observer = function (arr) {
                //This "refresh" is needed to begin observing new object properties
                _unobserve(observer, obj);
                _observe(observer, obj);

                var a = 0, alen = arr.length;
                while (a < alen) {
                    if (!(arr[a].name === 'length' && _isArray(arr[a].object)) && !(arr[a].name === '__Jasmine_been_here_before__')) {
                        var type = arr[a].type;

                        switch (type) {
                            case 'new':
                                type = 'add';
                                break;

                            case 'deleted':
                                type = 'delete';
                                break;

                            case 'updated':
                                type = 'update';
                                break;
                        }

                        var privates = privateProperties.get(arr[a].object);
                        if (!privates) {
                            privates = {};
                            privateProperties.set(arr[a].object, privates);
                        }
                        if (type === 'add') {
                            privates[arr[a].name] = true;
                        }
                        if (privates[arr[a].name]) {
                            return;
                        }

                        observeOps[type].call(arr[a], patches, getPath(root, arr[a].object));
                    }
                    a++;
                }

                if (patches) {
                    if (callback) {
                        callback(patches);
                    }
                }
                observer.patches = patches;
                patches = [];
            };
        } else {
            observer = {};

            mirror.value = JSON.parse(JSON.stringify(obj));

            if (callback) {
                //callbacks.push(callback); this has no purpose
                observer.callback = callback;
                observer.next = null;
                var intervals = this.intervals || [100, 1000, 10000, 60000];
                var currentInterval = 0;

                var dirtyCheck = function () {
                    generate(observer);
                };
                var fastCheck = function () {
                    clearTimeout(observer.next);
                    observer.next = setTimeout(function () {
                        dirtyCheck();
                        currentInterval = 0;
                        observer.next = setTimeout(slowCheck, intervals[currentInterval++]);
                    }, 0);
                };
                var slowCheck = function () {
                    dirtyCheck();
                    if (currentInterval == intervals.length)
                        currentInterval = intervals.length - 1;
                    observer.next = setTimeout(slowCheck, intervals[currentInterval++]);
                };
                if (typeof window !== 'undefined') {
                    if (window.addEventListener) {
                        window.addEventListener('mousedown', fastCheck);
                        window.addEventListener('mouseup', fastCheck);
                        window.addEventListener('keydown', fastCheck);
                    } else {
                        window.attachEvent('onmousedown', fastCheck);
                        window.attachEvent('onmouseup', fastCheck);
                        window.attachEvent('onkeydown', fastCheck);
                    }
                }
                observer.next = setTimeout(slowCheck, intervals[currentInterval++]);
            }
        }
        observer.patches = patches;
        observer.object = obj;

        mirror.observers.push(new ObserverInfo(callback, observer));

        return _observe(observer, obj);
    }
    jsonpatch.observe = observe;

    /// Listen to changes on an object tree, accumulate patches
    function _observe(observer, obj) {
        if (Object.observe) {
            Object.observe(obj, observer);
            for (var key in obj) {
                if (obj.hasOwnProperty(key)) {
                    var v = obj[key];
                    if (v && typeof (v) === "object") {
                        _observe(observer, v);
                    }
                }
            }
        }
        return observer;
    }

    function _unobserve(observer, obj) {
        if (Object.observe) {
            Object.unobserve(obj, observer);
            for (var key in obj) {
                if (obj.hasOwnProperty(key)) {
                    var v = obj[key];
                    if (v && typeof (v) === "object") {
                        _unobserve(observer, v);
                    }
                }
            }
        }
        return observer;
    }

    function generate(observer) {
        if (Object.observe) {
            Object.deliverChangeRecords(observer);
        } else {
            var mirror;
            for (var i = 0, ilen = beforeDict.length; i < ilen; i++) {
                if (beforeDict[i].obj === observer.object) {
                    mirror = beforeDict[i];
                    break;
                }
            }
            _generate(mirror.value, observer.object, observer.patches, "");
        }
        var temp = observer.patches;
        if (temp.length > 0) {
            observer.patches = [];
            if (observer.callback) {
                observer.callback(temp);
            }
        }
        return temp;
    }
    jsonpatch.generate = generate;

    var _objectKeys;
    if (Object.keys) {
        _objectKeys = Object.keys;
    } else {
        _objectKeys = function (obj) {
            var keys = [];
            for (var o in obj) {
                if (obj.hasOwnProperty(o)) {
                    keys.push(o);
                }
            }
            return keys;
        };
    }

    // Dirty check if obj is different from mirror, generate patches and update mirror
    function _generate(mirror, obj, patches, path) {
        var newKeys = _objectKeys(obj);
        var oldKeys = _objectKeys(mirror);
        var changed = false;
        var deleted = false;

        for (var t = oldKeys.length - 1; t >= 0; t--) {
            var key = oldKeys[t];
            var oldVal = mirror[key];
            if (obj.hasOwnProperty(key)) {
                var newVal = obj[key];
                if (oldVal instanceof Object) {
                    _generate(oldVal, newVal, patches, path + "/" + escapePathComponent(key));
                } else {
                    if (oldVal != newVal) {
                        changed = true;
                        patches.push({ op: "replace", path: path + "/" + escapePathComponent(key), value: newVal });
                        mirror[key] = newVal;
                    }
                }
            } else {
                patches.push({ op: "remove", path: path + "/" + escapePathComponent(key) });
                delete mirror[key];
                deleted = true;
            }
        }

        if (!deleted && newKeys.length == oldKeys.length) {
            return;
        }

        for (var t = 0; t < newKeys.length; t++) {
            var key = newKeys[t];
            if (!mirror.hasOwnProperty(key)) {
                patches.push({ op: "add", path: path + "/" + escapePathComponent(key), value: obj[key] });
                mirror[key] = JSON.parse(JSON.stringify(obj[key]));
            }
        }
    }

    var _isArray;
    if (Array.isArray) {
        _isArray = Array.isArray;
    } else {
        _isArray = function (obj) {
            return obj.push && typeof obj.length === 'number';
        };
    }

    /// Apply a json-patch operation on an object tree
    function apply(tree, patches) {
        var result = false, p = 0, plen = patches.length, patch;
        while (p < plen) {
            patch = patches[p];

            // Find the object
            var keys = patch.path.split('/');
            var obj = tree;
            var t = 1;
            var len = keys.length;
            while (true) {
                if (_isArray(obj)) {
                    var index = parseInt(keys[t], 10);
                    t++;
                    if (t >= len) {
                        result = arrOps[patch.op].call(patch, obj, index, tree);
                        break;
                    }
                    obj = obj[index];
                } else {
                    var key = keys[t];
                    if (key.indexOf('~') != -1)
                        key = key.replace(/~1/g, '/').replace(/~0/g, '~');
                    t++;
                    if (t >= len) {
                        result = objOps[patch.op].call(patch, obj, key, tree);
                        break;
                    }
                    obj = obj[key];
                }
            }
            p++;
        }
        return result;
    }
    jsonpatch.apply = apply;
})(jsonpatch || (jsonpatch = {}));

if (typeof exports !== "undefined") {
    exports.apply = jsonpatch.apply;
    exports.observe = jsonpatch.observe;
    exports.unobserve = jsonpatch.unobserve;
    exports.generate = jsonpatch.generate;
}