Method _renderUpdatedColumns

src/cdk/table/table.ts:1169–1195

* Check if the header, data, or footer rows have changed what columns they want to display or * whether the sticky states have changed for the header or footer. If there is a diff, then * re-render that section.

()

   * re-render that section.
   */
  private _renderUpdatedColumns(): boolean {
    const columnsDiffReducer = (acc: boolean, def: BaseRowDef) => {
      // The differ should be run for every column, even if `acc` is already
      // true (see #29922)
      const diff = !!def.getColumnsDiff();
      return acc || diff;
    };

    // Force re-render data rows if the list of column definitions have changed.
    const dataColumnsChanged = this._rowDefs.reduce(columnsDiffReducer, false);
    if (dataColumnsChanged) {
      this._forceRenderDataRows();
    }

    // Force re-render header/footer rows if the list of column definitions have changed.
    const headerColumnsChanged = this._headerRowDefs.reduce(columnsDiffReducer, false);
    if (headerColumnsChanged) {
      this._forceRenderHeaderRows();
    }

    const footerColumnsChanged = this._footerRowDefs.reduce(columnsDiffReducer, false);
    if (footerColumnsChanged) {
      this._forceRenderFooterRows();
    }

    return dataColumnsChanged || headerColumnsChanged || footerColumnsChanged;
  }

  /**
   * Switch to the provided data source by resetting the data and unsubscribing from the current