/** * Represents a grouping of items. The grouper works in a similar fashion as the * `Ext.util.Sorter` except that groups must be able to extract a value by which all items * in the group can be collected. By default this is derived from the `property` config * but can be customized using the `groupFn` if necessary. * * All items with the same group value compare as equal. If the group values do not compare * equally, the sort can be controlled further by setting `sortProperty` or `sorterFn`. */Ext.define('Ext.util.Grouper', { extend: 'Ext.util.Sorter', isGrouper: true, config: { /** * @cfg {Function} groupFn This function is called for each item in the collection * to determine the group to which it belongs. By default the `property` value is * used to group items. * @cfg {Object} groupFn.item The current item from the collection. * @cfg {String} groupFn.return The group identifier for the item. */ groupFn: null, /** * @cfg {String} property The field by which records are grouped. Groups are * sorted alphabetically by group value as the default. To sort groups by a different * property, use the {@link #sortProperty} configuration. */ /** * @cfg {String} sortProperty You can set this configuration if you want the groups * to be sorted on something other then the group string returned by the `groupFn`. * This serves the same role as `property` on a normal `Ext.util.Sorter`. */ sortProperty: null }, constructor: function(config) { //<debug> if (config) { if (config.getGroupString) { Ext.raise("Cannot set getGroupString - use groupFn instead"); } } //</debug> this.callParent(arguments); }, /** * Returns the value for grouping to be used. * @param {Ext.data.Model} item The Model instance * @return {String} */ getGroupString: function (item) { var group = this._groupFn(item); return (group != null) ? String(group) : ''; }, sortFn: function (item1, item2) { var me = this, lhs = me._groupFn(item1), rhs = me._groupFn(item2), property = me._sortProperty, // Sorter's sortFn uses "_property" root = me._root, sorterFn = me._sorterFn, transform = me._transform; // Items with the same groupFn result must be equal... otherwise we sort them // by sorterFn or sortProperty. if (lhs === rhs) { return 0; } if (property || sorterFn) { if (sorterFn) { return sorterFn.call(this, item1, item2); } if (root) { item1 = item1[root]; item2 = item2[root]; } lhs = item1[property]; rhs = item2[property]; if (transform) { lhs = transform(lhs); rhs = transform(rhs); } } return (lhs > rhs) ? 1 : (lhs < rhs ? -1 : 0); }, standardGroupFn: function (item) { var root = this._root; return (root ? item[root] : item)[this._property]; }, updateSorterFn: function () { // don't callParent here - we don't want to smash sortFn w/sorterFn }, updateProperty: function () { // we don't callParent since that is related to sorterFn smashing sortFn if (!this.getGroupFn()) { this.setGroupFn(this.standardGroupFn); } }});