mountInstance()

in packages/react-simulator-renderer/src/renderer.ts [112:171]

• 52 lines of code
• 13 McCabe index (conditional complexity)

  mountInstance(id: string, instance: ReactInstance | null) {
    const docId = this.document.id;
    const { instancesMap } = this;
    if (instance == null) {
      let instances = this.instancesMap.get(id);
      if (instances) {
        instances = instances.filter(checkInstanceMounted);
        if (instances.length > 0) {
          instancesMap.set(id, instances);
          host.setInstance(this.document.id, id, instances);
        } else {
          instancesMap.delete(id);
          host.setInstance(this.document.id, id, null);
        }
      }
      return;
    }
    const unmountInstance = this.unmountInstance.bind(this);
    const origId = (instance as any)[SYMBOL_VNID];
    if (origId && origId !== id) {
      // 另外一个节点的 instance 在此被复用了，需要从原来地方卸载
      unmountInstance(origId, instance);
    }
    if (isElement(instance)) {
      cacheReactKey(instance);
    } else if (origId !== id) {
      // 涵盖 origId == null || origId !== id 的情况
      let origUnmount: any = instance.componentWillUnmount;
      if (origUnmount && origUnmount.origUnmount) {
        origUnmount = origUnmount.origUnmount;
      }
      // hack! delete instance from map
      const newUnmount = function (this: any) {
        unmountInstance(id, instance);
        origUnmount && origUnmount.call(this);
      };
      (newUnmount as any).origUnmount = origUnmount;
      instance.componentWillUnmount = newUnmount;
    }

    (instance as any)[SYMBOL_VNID] = id;
    (instance as any)[SYMBOL_VDID] = docId;
    let instances = this.instancesMap.get(id);
    if (instances) {
      const l = instances.length;
      instances = instances.filter(checkInstanceMounted);
      let updated = instances.length !== l;
      if (!instances.includes(instance)) {
        instances.push(instance);
        updated = true;
      }
      if (!updated) {
        return;
      }
    } else {
      instances = [instance];
    }
    instancesMap.set(id, instances);
    host.setInstance(this.document.id, id, instances);
  }