Method deserializeState

src/state.ts:170–239

* Deserializes the state from the url hash.

()

   * Deserializes the state from the url hash.
   */
  static deserializeState(): State {
    let map: {[key: string]: string} = {};
    for (let keyvalue of window.location.hash.slice(1).split("&")) {
      let [name, value] = keyvalue.split("=");
      map[name] = value;
    }
    let state = new State();

    function hasKey(name: string): boolean {
      return name in map && map[name] != null && map[name].trim() !== "";
    }

    function parseArray(value: string): string[] {
      return value.trim() === "" ? [] : value.split(",");
    }

    // Deserialize regular properties.
    State.PROPS.forEach(({name, type, keyMap}) => {
      switch (type) {
        case Type.OBJECT:
          if (keyMap == null) {
            throw Error("A key-value map must be provided for state " +
                "variables of type Object");
          }
          if (hasKey(name) && map[name] in keyMap) {
            state[name] = keyMap[map[name]];
          }
          break;
        case Type.NUMBER:
          if (hasKey(name)) {
            // The + operator is for converting a string to a number.
            state[name] = +map[name];
          }
          break;
        case Type.STRING:
          if (hasKey(name)) {
            state[name] = map[name];
          }
          break;
        case Type.BOOLEAN:
          if (hasKey(name)) {
            state[name] = (map[name] === "false" ? false : true);
          }
          break;
        case Type.ARRAY_NUMBER:
          if (name in map) {
            state[name] = parseArray(map[name]).map(Number);
          }
          break;
        case Type.ARRAY_STRING:
          if (name in map) {
            state[name] = parseArray(map[name]);
          }
          break;
        default:
          throw Error("Encountered an unknown type for a state variable");
      }
    });