_setValue: function (value, options) {

        // we try to avoid doing useless work, if the value given has not

        // changed.  Note that we compare the unparsed values.

        if (this.lastSetValue === value || (this.value === false && value === '')) {

            return $.when();

        }

        this.lastSetValue = value;

        try {

            value = this._parseValue(value);

            this._isValid = true;

        } catch (e) {

            this._isValid = false;

            this.trigger_up('set_dirty', {dataPointID: this.dataPointID});

            return $.Deferred().reject();

        }

        // 下面这个地方

        if (!(options && options.forceChange) && this._isSameValue(value)) {

            return $.when();

        }

        var def = $.Deferred();

        var changes = {};

        changes[this.name] = value;

        this.trigger_up('field_changed', {

            dataPointID: this.dataPointID,

            changes: changes,

            viewType: this.viewType,

            doNotSetDirty: options && options.doNotSetDirty,

            notifyChange: !options || options.notifyChange !== false,

            onSuccess: def.resolve.bind(def),

            onFailure: def.reject.bind(def),

        });

        return def;

    },