Q:

How to prevent changing checkcolumn in ext treepanel

I have ext treepanel and checkcolumn inside.... So I need to prevent unchecking some of nodes of tree.
For example I have tree with categories... And category with ID 5 has to be always checked...,
I've added listener for checkcolumn but the only I catch is row index and I cannot find model by this index and equate record id to my category...
        'categoryViewWindow treepanel checkcolumn'           : {
            beforecheckchange : function(holder, rowIndex, checked, eOpts){
                debugger;
            }
        }

A:

So Ive done it something like this in my controller
this.control({
            'categoryViewWindow checkcolumn'      : {
                checkchange: me.checkCategoryView,
            }
});

And method
checkCategoryView: function () {
    var me = this,
        categoriesViewStore = me.getCategoriesViewStore(),
        myId;

    if (category && category.get('id') != -1) {
        foundCategory = categoriesViewStore.getNodeById(myId);

        if (foundCategory) {
            foundCategory.set('added', true);
        }
    }
},

So after change I check my category forcibly

