const merge = Object.assign; const STOP_CRAWLING = {}; /** * Check if the argument is an instance of a class */ function isObject(value: any): boolean { return value instanceof Object && !Array.isArray(value); } /** * Recursively crawl through an object, yielding any defined value found along the way * * If *replace* is set to true, the current object is replaced (in array or object attribute) by the result of the callback * * *memo* is used to prevent circular references to be traversed */ function crawl(obj: any, callback: (item: any) => any, replace = false, memo: any[] = []) { if (isObject(obj)) { if (memo.indexOf(obj) >= 0) { return obj; } else { memo.push(obj); } } if (obj !== undefined && obj !== null && typeof obj != "function") { let result = callback(obj); if (result === STOP_CRAWLING) { return; } if (Array.isArray(obj)) { let subresult = obj.map(value => crawl(value, callback, replace, memo)); if (replace) { subresult.forEach((value, index) => { obj[index] = value; }); } } else if (obj instanceof Object) { let subresult: any = {}; for (let key in obj) { subresult[key] = crawl(obj[key], callback, replace, memo); } if (replace) { merge(obj, subresult); } } return result; } else { return obj; } } /** * Get the class name of an object. */ function classname(obj: Object): string { return (obj.constructor).name; } /** * A deep serializer of javascript objects. */ export class Serializer { private namespace: any; private ignored: string[] = []; constructor(namespace: any) { this.namespace = namespace; } /** * Add a class to the ignore list */ addIgnoredClass(name: string) { this.ignored.push(name); } /** * Construct an object from a constructor name */ private constructObject(ctype: string): Object { if (ctype == "Object") { return {}; } else { let cl = this.namespace[ctype]; if (cl) { return Object.create(cl.prototype); } else { console.error("Can't find class", ctype); return {}; } } } /** * Serialize an object to a string */ serialize(obj: any): string { // Collect objects var objects: Object[] = []; var stats: any = {}; crawl(obj, value => { if (isObject(value)) { var vtype = classname(value); if (vtype != "" && this.ignored.indexOf(vtype) < 0) { stats[vtype] = (stats[vtype] || 0) + 1; if (objects.indexOf(value) < 0) { objects.push(value); } return value; } else { return STOP_CRAWLING; } } else { return value; } }); //console.log("Serialize stats", stats); // Serialize objects list, transforming deeper objects to links var fobjects = objects.map(value => { $c: classname(value), $f: merge({}, value) }); return JSON.stringify(fobjects, (key, value) => { if (key != "$f" && isObject(value) && !value.hasOwnProperty("$c") && !value.hasOwnProperty("$i")) { return { $i: objects.indexOf(value) }; } else { return value; } }); } /** * Unserialize a string to an object */ unserialize(data: string): any { // Unserialize objects list var fobjects = JSON.parse(data); // Reconstruct objects var objects = fobjects.map((objdata: any) => merge(this.constructObject(objdata['$c']), objdata['$f'])); // Reconnect links crawl(objects, value => { if (value instanceof Object && value.hasOwnProperty('$i')) { return objects[value['$i']]; } else { return value; } }, true); // Post unserialize hooks crawl(objects[0], value => { if (value instanceof Object && typeof value.postUnserialize === "function") { value.postUnserialize(); } }); // First object was the root return objects[0]; } }