Function allocExpando

packages/core/src/render3/view/construction.ts:282–307

(
  tView: TView,
  lView: LView,
  numSlotsToAlloc: number,
  initialValue: unknown,
)

 * @param initialValue Initial value to store in blueprint
 */
export function allocExpando(
  tView: TView,
  lView: LView,
  numSlotsToAlloc: number,
  initialValue: unknown,
): number {
  if (numSlotsToAlloc === 0) return -1;
  if (ngDevMode) {
    assertFirstCreatePass(tView);
    assertSame(tView, lView[TVIEW], '`LView` must be associated with `TView`!');
    assertEqual(tView.data.length, lView.length, 'Expecting LView to be same size as TView');
    assertEqual(
      tView.data.length,
      tView.blueprint.length,
      'Expecting Blueprint to be same size as TView',
    );
    assertFirstUpdatePass(tView);
  }
  const allocIdx = lView.length;
  for (let i = 0; i < numSlotsToAlloc; i++) {
    lView.push(initialValue);
    tView.blueprint.push(initialValue);
    tView.data.push(null);
  }
  return allocIdx;
}

/**
 * Adds LView or LContainer to the end of the current view tree.