POC DataTable.Selection class extension

gistfile1.js

// Class extension to DataTable ...

Y.DataTable.Selection = function () {}

Y.DataTable.Selection.ATTRS = {
    // selectionMode: for supporting multiple selection could be its own extension

    selectionType: {
        value: null, // Feature should not change base behavior by default
        validator: '_validateSelectionType'
    },

    selection: {
        setter: '_setSelection'
    }
};

Y.mix(Y.DataTable.Selection.prototype, {
    initializer: function () {
        this.after('selectionTypeChange', this._afterSelectionTypeChange);

        this._initSelectionType(this.get('selectionType'));
    },

    _initSelectionType: function (mode) {
        var rendered = this.get('rendered');

        if (!this.get('rendered')) {
            if (mode && !this._initSelectionHandle) {
                this._initSelectionHandle = this.after('renderTable', this._bindSelectionUI)
            } else if (!mode && this._initSelectionHandle) {
                this._initSelectionHandle.detach();
                delete this._initSelectionHandle;
            }
        } else {
            this._bindSelectionUI();
        }
    },

    _afterSelectionTypeChange: function (e) {
        this._initSelectionType(e.newVal);
    },

    _bindSelectionUI: function () {
        if (!this._selectionHandle) {
            // Not a delegate because a click will always result in something being selected
            this._selectionHandle = this.get('contentBox').on('click', this._onClickSelect, this);
        }
    },

    _onClickSelect: function (e) {
        this.set('selection', e.target);
    },

    _setSelection: function (val) {
        var type;

        if (val) {
            type = this.get('selectionType');

            if (type === 'cell') {
                val = val.ancestor('.' + this.getClassName('cell'));
            } else if (type === 'row') {
                val = val.ancestor('.' + this.getClassName('data') + '> tr');
            } else if (type === 'column') {
                val = this.getColumn(val);
            }
        }

        return val || null;
    },

    _validateSelectionType: function (val) {
        return val === 'cell' || val === 'row' || val === 'column' || val === null;
    }
});

// Mix the class extension into Y.DataTable
Y.Base.mix(Y.DataTable, [ Y.DataTable.Selection ]);

var newDT = new Y.DataTable({
    selectionType: 'cell'
}); 

newDT.on("selectionChange", function(e){
    // do something ...
});