agGridReact.ts

export class AgGridReact extends React.Component {
    gridOptions: AgGrid.GridOptions;

    componentDidMount() {
        ...
        
        let gridOptions = this.props.gridOptions || {};
        if (AgGridColumn.hasChildColumns(this.props)) {
            gridOptions.columnDefs = AgGridColumn.mapChildColumnDefs(this.props);
        }

        this.gridOptions = AgGrid.ComponentUtil.copyAttributesToGridOptions(gridOptions, this.props);

        // don't need the return value
        new AgGrid.Grid(this.eGridDiv, this.gridOptions, gridParams);

        this.api = this.gridOptions.api;
        this.columnApi = this.gridOptions.columnApi;
    }
}