Method _cacheRowDefs

src/cdk/table/table.ts:1132–1162

Update the list of all available row definitions that can be used.

()

  /** Update the list of all available row definitions that can be used. */
  private _cacheRowDefs() {
    this._headerRowDefs = mergeArrayAndSet(
      this._getOwnDefs(this._contentHeaderRowDefs),
      this._customHeaderRowDefs,
    );
    this._footerRowDefs = mergeArrayAndSet(
      this._getOwnDefs(this._contentFooterRowDefs),
      this._customFooterRowDefs,
    );
    this._rowDefs = mergeArrayAndSet(this._getOwnDefs(this._contentRowDefs), this._customRowDefs);

    // After all row definitions are determined, find the row definition to be considered default.
    const defaultRowDefs = this._rowDefs.filter(def => !def.when);

    if (typeof ngDevMode === 'undefined' || ngDevMode) {
      // At the moment of writing, it's tricky to support `when` with virtual scrolling
      // because we reuse templates and they can change arbitrarily based on the `when`
      // condition. We may be able to support it in the future (see #32670).
      if (this._virtualScrollEnabled() && this._rowDefs.some(def => def.when)) {
        throw new Error(
          'Conditional row definitions via the `when` input are not ' +
            'supported when virtual scrolling is enabled, at the moment.',
        );
      }

      if (!this.multiTemplateDataRows && defaultRowDefs.length > 1) {
        throw getTableMultipleDefaultRowDefsError();
      }
    }
    this._defaultRowDef = defaultRowDefs[0];
  }

  /**
   * Check if the header, data, or footer rows have changed what columns they want to display or