RESTful store example as a pre-configured class

The ExtJS 3.2+ examples include a “RESTful store” which is a very interesting no-code way to get full CRUD behaviour from a GridPanel. Unfortunately the example is not written with a reusable structure - here is the same example, but as a pre-configured class:

Ext.onReady(function() {
            Ext.QuickTips.init();

            var TheGrid = Ext.extend(Ext.grid.GridPanel, {
                        title: 'Users',
                        frame: true,
                        height: 300,
                        width: 500,
                        viewConfig: {
                            forceFit: true
                        },
                        editor: new Ext.ux.grid.RowEditor({
                                    saveText: 'Update'
                                }),


                        onAdd: function(btn, ev) {
                            var u = new this.store.recordType({
                                        first: '',
                                        last: '',
                                        email: ''
                                    });
                            this.editor.stopEditing();
                            this.store.insert(0, u);
                            this.editor.startEditing(0);
                        },


                        onDelete: function() {
                            var rec = this.getSelectionModel().getSelected();
                            if (rec) {
                                this.store.remove(rec);
                            }
                        },


                        initComponent: function() {
                            var proxy = new Ext.data.HttpProxy({
                                        url: 'app.php/users'
                                    });

                            var reader = new Ext.data.JsonReader({
                                        totalProperty: 'total',
                                        successProperty: 'success',
                                        idProperty: 'id',
                                        root: 'data',
                                        messageProperty: 'message' // attribute in server response for user message...
                                    }, [{
                                                name: 'id'
                                            }, {
                                                name: 'email'
                                            }, {
                                                name: 'first',
                                                allowBlank: false
                                            }, {
                                                name: 'last'
                                            }]);

                            var writer = new Ext.data.JsonWriter({
                                        encode: false
                                    });

                            var store = new Ext.data.Store({
                                        restful: true,
                                        proxy: proxy,
                                        reader: reader,
                                        writer: writer
                                    });

                            var config = {
                                store: store,
                                plugins: [this.editor],
                                columns: [{
                                            header: "ID",
                                            width: 40,
                                            sortable: true,
                                            dataIndex: 'id'
                                        }, {
                                            header: "Email",
                                            width: 100,
                                            sortable: true,
                                            dataIndex: 'email',
                                            editor: new Ext.form.TextField({})
                                        }, {
                                            header: "First",
                                            width: 50,
                                            sortable: true,
                                            dataIndex: 'first',
                                            editor: new Ext.form.TextField({})
                                        }, {
                                            header: "Last",
                                            width: 50,
                                            sortable: true,
                                            dataIndex: 'last',
                                            editor: new Ext.form.TextField({})
                                        }],
                                tbar: [{
                                            text: 'Add',
                                            iconCls: 'silk-add',
                                            handler: this.onAdd,
                                            scope: this
                                        }, '-', {
                                            text: 'Delete',
                                            iconCls: 'silk-delete',
                                            handler: this.onDelete,
                                            scope: this
                                        }, '-']
                            };

                            Ext.apply(this, Ext.apply(this.initialConfig, config));
                            TheGrid.superclass.initComponent.apply(this, arguments);

                        },


                        onRender: function() {
                            this.store.load();
                            TheGrid.superclass.onRender.apply(this, arguments);
                        }
                    });
            Ext.reg('my_grid', TheGrid);



            var w = new Ext.Window({
                        modal: true,
                        items: {
                            xtype: 'my_grid',
                            title: 'Panel 1'
                        }
                    });
            w.show();
        });