Method empty

frontend/lib/src/render-tree/AppRoot.ts:100–183

* Create an empty AppRoot with a placeholder "skeleton" element. * @param mainScriptHash - The hash of the main script that creates this AppRoot. * @param isInitialRender - Whether this is the initial render. * @param sidebarElements - The elements to add to the sidebar (this was a relic

(
    mainScriptHash = "",
    isInitialRender = true,
    sidebarElements?: BlockNode,
    logo?: Logo | null
  )

   * @returns A new AppRoot with the given parameters.
   */
  public static empty(
    mainScriptHash = "",
    isInitialRender = true,
    sidebarElements?: BlockNode,
    logo?: Logo | null
  ): AppRoot {
    const mainNodes: AppNode[] = []

    let waitElement: Element | undefined

    switch (getLoadingScreenType()) {
      case LoadingScreenType.NONE:
        break

      case LoadingScreenType.V1:
        // Only show the v1 loading state when it's the initial render.
        // This is how v1 used to work, and we don't want any backward
        // incompatibility.
        if (isInitialRender) {
          waitElement = makeElementWithInfoText("Please wait...")
        }
        break

      default:
        waitElement = makeAppSkeletonElement()
        break
    }

    if (waitElement) {
      mainNodes.push(
        new ElementNode(
          waitElement,
          ForwardMsgMetadata.create({}),
          NO_SCRIPT_RUN_ID,
          mainScriptHash
        )
      )
    }

    const main = new BlockNode(
      mainScriptHash,
      mainNodes,
      new BlockProto({ allowEmpty: true }),
      NO_SCRIPT_RUN_ID
    )

    const sidebar =
      sidebarElements ||
      new BlockNode(
        mainScriptHash,
        [],
        new BlockProto({ allowEmpty: true }),
        NO_SCRIPT_RUN_ID
      )

    const event = new BlockNode(
      mainScriptHash,
      [],