Function setup

packages/runtime-core/src/components/KeepAlive.ts:93–373

(props: KeepAliveProps, { slots }: SetupContext)

  },

  setup(props: KeepAliveProps, { slots }: SetupContext) {
    const instance = getCurrentInstance()!
    // KeepAlive communicates with the instantiated renderer via the
    // ctx where the renderer passes in its internals,
    // and the KeepAlive instance exposes activate/deactivate implementations.
    // The whole point of this is to avoid importing KeepAlive directly in the
    // renderer to facilitate tree-shaking.
    const sharedContext = instance.ctx as KeepAliveContext

    // if the internal renderer is not registered, it indicates that this is server-side rendering,
    // for KeepAlive, we just need to render its children
    if (__SSR__ && !sharedContext.renderer) {
      return () => {
        const children = slots.default && slots.default()
        return children && children.length === 1 ? children[0] : children
      }
    }

    const cache: Cache = new Map()
    const keys: Keys = new Set()
    let current: VNode | null = null

    if (__DEV__ || __FEATURE_PROD_DEVTOOLS__) {
      ;(instance as any).__v_cache = cache
    }

    const parentSuspense = instance.suspense

    const {
      renderer: {
        p: patch,
        m: move,
        um: _unmount,
        o: { createElement },
      },
    } = sharedContext
    const storageContainer = createElement('div')

    sharedContext.activate = (
      vnode,
      container,
      anchor,
      namespace,
      optimized,
    ) => {
      const instance = vnode.component!
      move(vnode, container, anchor, MoveType.ENTER, parentSuspense)
      // in case props have changed
      patch(
        instance.vnode,
        vnode,
        container,
        anchor,
        instance,
        parentSuspense,
        namespace,
        vnode.slotScopeIds,
        optimized,