public function computed(callable $groupDataCallback) : ColumnMappingDefiner
    {
        return new ColumnMappingDefiner(
            function (IColumn $column) use ($groupDataCallback) {
                $this->column($column);
                $this->componentIdCallableMap[$column->getComponentId()] = $groupDataCallback;
            },
            function ($componentId) use ($groupDataCallback) {
                $this->componentIdCallableMap[$componentId] = $groupDataCallback;
            }
        );
    }
public function computed(callable $groupDataCallback) : ColumnMappingDefiner
    {
        return new ColumnMappingDefiner(
            function (IColumn $column) use ($groupDataCallback) {
                $this->column($column);
                $this->componentIdCallableMap[$column->getComponentId()] = $groupDataCallback;
            },
            function ($componentId) use ($groupDataCallback) {
                $this->componentIdCallableMap[$componentId] = $groupDataCallback;
            }
        );
    }
public function computed ( callable $ groupDataCallback ) : ColumnMappingDefiner { return new ColumnMappingDefiner ( function ( IColumn $ column ) use ( $ groupDataCallback ) { $ this -> column ( $ column ) ; $ this -> componentIdCallableMap [ $ column -> getComponentId ( ) ] = $ groupDataCallback ; } , function ( $ componentId ) use ( $ groupDataCallback ) { $ this -> componentIdCallableMap [ $ componentId ] = $ groupDataCallback ; } ) ; }
Defines a callback to get the data from each group for the mapped column component.

@param callable $groupDataCallback

@return ColumnMappingDefiner
Defines a callback to get the data from each group for the mapped column component .