setColumnDefs在Angular 5中不起作用

Question

As what has been suggested elsewhere,

setColumnDefs is not working for some ag-grids

How to initialize ag-grid api in angular2 application

I have already initialized the gridOptions in my class constructor. But when I tried to setColumnDefs, it still gave me error:

TypeError: Cannot read property 'setColumnDefs' of undefined

What else am I missing here?

export class ConfigurationComponent implements OnInit {
  constructor(
    private configurationService: ConfigurationService,
    ) 
    {
      this.gridOptions = {
        enableSorting: false,
        rowData: this.tableData,
        columnDefs: this.tableColumns,
        onGridReady: () => {
          this.gridOptions.api.sizeColumnsToFit();
          this.gridOptions.api.setColumnDefs(this.tableColumns);
          alert(this.gridOptions.api);
        }
      }
    }

  tableData: string[] = [];
  tableList: string[] = [];
  tableName: string;
  tableColumns: [{headerName: string, field: string}] = [{headerName: "", field: ""}];
  tableRecord: {};
  gridOptions: GridOptions;

  ngOnInit() {   
    this.retrieveTableList();
  }

  retrieveTableList(){
    /*blah blah*/
  }

  retrieveTableData(){
    /*blah blah*/
    this.configurationService.retrieveTableData(this.schemaFullname, this.tableName).subscribe(data => {
      /* GETTING tableColumn HERE from the service*/

      this.gridOptions.api.setColumnDefs(this.tableColumns);

    }, error => {
      console.error(error);
      this.alertService.error("Get table data error", "No table data retrieved from data source for " + this.tableName);
    })
  }
}

Answer 1

As your comment says,

It works now after I added [gridOptions]="gridOptions" in html.

Do you know why it worked?

As in your code, you are defining gridOptions in your constructor. In your onGridReady function, nobody knows from where api property (and sizeColumnsToFit , etc methods) gets added.

  this.gridOptions = {
    enableSorting: false,
    rowData: this.tableData,
    columnDefs: this.tableColumns,
    onGridReady: () => {
      this.gridOptions.api.sizeColumnsToFit();
      this.gridOptions.api.setColumnDefs(this.tableColumns);
      alert(this.gridOptions.api);
    }
  }

When you add [gridOptions]="gridOptions" in your component, ag-grid component uses the gridOptions object and injects other apis for you. Hence, it works afterwards.