Function stateMixin

m3u8/vue.js:4898–4947

(Vue)

  }

  function stateMixin (Vue) {
    // flow somehow has problems with directly declared definition object
    // when using Object.defineProperty, so we have to procedurally build up
    // the object here.
    var dataDef = {};
    dataDef.get = function () { return this._data };
    var propsDef = {};
    propsDef.get = function () { return this._props };
    {
      dataDef.set = function () {
        warn(
          'Avoid replacing instance root $data. ' +
          'Use nested data properties instead.',
          this
        );
      };
      propsDef.set = function () {
        warn("$props is readonly.", this);
      };
    }
    Object.defineProperty(Vue.prototype, '$data', dataDef);
    Object.defineProperty(Vue.prototype, '$props', propsDef);

    Vue.prototype.$set = set;
    Vue.prototype.$delete = del;

    Vue.prototype.$watch = function (
      expOrFn,
      cb,
      options
    ) {
      var vm = this;
      if (isPlainObject(cb)) {
        return createWatcher(vm, expOrFn, cb, options)
      }
      options = options || {};
      options.user = true;
      var watcher = new Watcher(vm, expOrFn, cb, options);
      if (options.immediate) {
        try {
          cb.call(vm, watcher.value);
        } catch (error) {
          handleError(error, vm, ("callback for immediate watcher \"" + (watcher.expression) + "\""));
        }
      }
      return function unwatchFn () {
        watcher.teardown();
      }
    };
  }

  /*  */