Reading / writing extended user fields from CMP (grid)

GoodNews.grid.Subscribers = function(config){
    config = config || {};

    Ext.applyIf(config,{
        id: 'goodnews-grid-subscribers'
        ,url: GoodNews.config.connectorUrl
        ,baseParams: { action: 'mgr/subscribers/getList' }
        ,fields: [
            'id'
            ,'username'
            ,'fullname'
            ,'email'
            ,'newslettercategories'
            ,'extended'
            ,'menu'
        ]
        ,emptyText: _('goodnews.subscribers_none')
        ,paging: true
        ,remoteSort: true
        ,columns: [{
            header: _('goodnews.subscriber_username')
            ,dataIndex: 'username'
            ,sortable: true
            ,width: 100
        },{
            header: _('goodnews.subscriber_fullname')
            ,dataIndex: 'fullname'
            ,sortable: true
            ,width: 100
        },{
            header: _('goodnews.subscriber_email')
            ,dataIndex: 'email'
            ,sortable: true
            ,width: 100
        },{
            header: _('goodnews.subscriber_categories')
            ,dataIndex: 'newslettercategories'
            ,width: 100
        },{
            header: 'Extended (debug)'
            ,dataIndex: 'extended'
            ,width: 100
        }]
        ,tbar:['->',{
            xtype: 'modx-combo-usergroup'
            ,name: 'usergroup'
            ,id: 'goodnews-user-filter-usergroup'
            ,itemId: 'usergroup'
            ,emptyText: _('goodnews.subscribers_user_group')+'...'
            ,baseParams: {
                action: 'getList'
                ,addAll: true
            }
            ,value: MODx.request['usergroup'] ? MODx.request['usergroup'] : ''
            ,width: 200
            ,listeners: {
                'select': {fn:this.filterUsergroup,scope:this}
            }
        },'-',{
            xtype: 'textfield'
            ,id: 'goodnews-subscribers-search-filter'
            ,emptyText: _('goodnews.subscribers_search...')
            ,listeners: {
                'change': {fn:this.search,scope:this}
                ,'render': {fn: function(cmp) {
                    new Ext.KeyMap(cmp.getEl(), {
                        key: Ext.EventObject.ENTER
                        ,fn: function() {
                            this.fireEvent('change',this);
                            this.blur();
                            return true;
                        }
                        ,scope: cmp
                    });
                },scope:this}
            }
        },{
            xtype: 'button'
            ,id: 'goodnews-subscribers-filter-clear'
            ,text: _('filter_clear')
            ,listeners: {
                'click': {fn: this.clearFilter,scope:this}
            }
        }]
    });
    GoodNews.grid.Subscribers.superclass.constructor.call(this,config);
};
Ext.extend(GoodNews.grid.Subscribers,MODx.grid.Grid,{
    getMenu: function() {
        var r = this.getSelectionModel().getSelected();
        var p = r.data.perm;

        return [{
            text: _('goodnews.subscriber_update')
            ,handler: this.updateSubscriber
        },'-',{
            text: _('goodnews.user_update')
            ,handler: this.updateUser
        }];
    }
    ,updateSubscriber: function(btn,e) {
        //needs to be destroyed in order to recreate checkboxgroup!
        if (this.updateSubscriberWindow) {
            this.updateSubscriberWindow.destroy();
        }
        this.updateSubscriberWindow = MODx.load({
            xtype: 'goodnews-window-subscriber-update'
            ,record: this.menu.record
            ,scope: this
            ,listeners: {
                'success': {fn:this.refresh,scope:this}
            }
        });
        this.updateSubscriberWindow.setValues(this.menu.record);
        this.updateSubscriberWindow.show(e.target);
    }
    ,updateUser: function(btn,e) {
        location.href = 'index.php?a='+MODx.action['security/user/update']+'&id='+this.menu.record.id;
    }
    ,filterUsergroup: function(cb,nv,ov) {
        this.getStore().baseParams.usergroup = Ext.isEmpty(nv) || Ext.isObject(nv) ? cb.getValue() : nv;
        this.getBottomToolbar().changePage(1);
        this.refresh();
        return true;
    }
    ,search: function(tf,nv,ov) {
        var s = this.getStore();
        s.baseParams.query = tf.getValue();
        this.getBottomToolbar().changePage(1);
        this.refresh();
    }
    ,clearFilter: function() {
    	this.getStore().baseParams = {
            action: 'mgr/subscribers/getList'
    	};
        Ext.getCmp('goodnews-subscribers-search-filter').reset();
        Ext.getCmp('goodnews-user-filter-usergroup').reset();
    	this.getBottomToolbar().changePage(1);
    }
});
Ext.reg('goodnews-grid-subscribers',GoodNews.grid.Subscribers);


GoodNews.window.UpdateSubscriber = function(config) {
    config = config || {};
    
    console.log(this);

    Ext.applyIf(config,{
        title: _('goodnews.subscriber_update')
        ,url: GoodNews.config.connectorUrl
        ,baseParams: {
            action: 'mgr/subscribers/update'
        }
        ,fields: [{
            xtype: 'hidden'
            ,name: 'id'
        },{
            xtype: 'displayfield'
            ,fieldLabel: 'extended field'
            ,name: 'extended'
            ,readOnly: true
        },{
            xtype: 'displayfield'
            ,fieldLabel: _('goodnews.subscriber_username')
            ,name: 'username'
            ,readOnly: true
        },{
            id: 'cat-ext-checkboxgroup'
            ,fieldLabel: _('goodnews.subscriber_categories')
            ,name: 'newslettercategories'
            ,listeners: {
                'render': {
                    fn: function() {
                        catCheckboxGroup('cat-ext-checkboxgroup','newslettercategories');
                    }
                }
            }

        }]
    });
    GoodNews.window.UpdateSubscriber.superclass.constructor.call(this,config);     
};
Ext.extend(GoodNews.window.UpdateSubscriber,MODx.Window);
Ext.reg('goodnews-window-subscriber-update',GoodNews.window.UpdateSubscriber);

function catCheckboxGroup(renderTarget,groupName) {
    Ext.onReady(function() {
        var catStore = new Ext.data.JsonStore({
            url: GoodNews.config.connectorUrl
            ,baseParams: {
                action: 'mgr/category/getList'
            }
            ,fields: ['id','name','uniquekey']
            ,root: 'results'
            ,autoLoad: false
            ,autoDestroy: true
            ,listeners: {
                'load': {
                    fn: function(t, records, options, success) {
                        var catArray = [];
                        for (var i=0; i<records.length; i++) {
                            catArray.push({
                                name: groupName+'['+records[i].data.uniquekey+']'
                                ,inputValue: records[i].data.id
                                ,boxLabel: records[i].data.name
                            });
                        }
                        var catCheckboxGroup = new Ext.form.CheckboxGroup({
                            items: catArray
                            ,columns: 2
                            ,renderTo: renderTarget
                        });
                        //console.log(catArray);
                    }
                }
                /*,'loadexception': {
                    fn: function(obj, options, response, e){
                        console.info('store loadexception, arguments:', arguments);
                        console.info('error = ', e);
                    }
                }*/
            }
        });
        catStore.load();
    });
};

<?php
class CategoryGetListProcessor extends modObjectGetListProcessor {
    public $classKey = 'GoodNewsCategory';
    public $languageTopics = array('goodnews:default');
    public $defaultSortField = 'name';
    public $defaultSortDirection = 'ASC';
    public $objectType = 'goodnews.category';

    public function prepareQueryBeforeCount(xPDOQuery $c) {
        $query = $this->getProperty('query');
        if (!empty($query)) {
            $c->where(array(
                'name:LIKE' => '%'.$query.'%',
                'OR:description:LIKE' => '%'.$query.'%',
                'OR:uniquekey:LIKE' => '%'.$query.'%',
            ));
        }
        return $c;
    }

    public function prepareRow(xPDOObject $object) {
        $resourceArray = parent::prepareRow($object);




        return $resourceArray;
    }

}
return 'CategoryGetListProcessor';