initSetup() — vue Function Reference

Source Code

src/v3/apiSetup.ts lines 28–85

export function initSetup(vm: Component) {
  const options = vm.$options
  const setup = options.setup
  if (setup) {
    const ctx = (vm._setupContext = createSetupContext(vm))

    setCurrentInstance(vm)
    pushTarget()
    const setupResult = invokeWithErrorHandling(
      setup,
      null,
      [vm._props || shallowReactive({}), ctx],
      vm,
      `setup`
    )
    popTarget()
    setCurrentInstance()

    if (isFunction(setupResult)) {
      // render function
      // @ts-ignore
      options.render = setupResult
    } else if (isObject(setupResult)) {
      // bindings
      if (__DEV__ && setupResult instanceof VNode) {
        warn(
          `setup() should not return VNodes directly - ` +
            `return a render function instead.`
        )
      }
      vm._setupState = setupResult
      // __sfc indicates compiled bindings from <script setup>
      if (!setupResult.__sfc) {
        for (const key in setupResult) {
          if (!isReserved(key)) {
            proxyWithRefUnwrap(vm, setupResult, key)
          } else if (__DEV__) {
            warn(`Avoid using variables that start with _ or $ in setup().`)
          }
        }
      } else {
        // exposed for compiled render fn
        const proxy = (vm._setupProxy = {})
        for (const key in setupResult) {
          if (key !== '__sfc') {
            proxyWithRefUnwrap(proxy, setupResult, key)
          }
        }
      }
    } else if (__DEV__ && setupResult !== undefined) {
      warn(
        `setup() should return an object. Received: ${
          setupResult === null ? 'null' : typeof setupResult
        }`
      )
    }
  }
}