TypeScript nerv-utils.isFunction函數代碼示例

export function mountComponent (vnode: FullComponent, parentContext: object, parentComponent) {
  const ref = vnode.props.ref
  vnode.component = new vnode.type(vnode.props, parentContext)
  const component = vnode.component
  if (isComponent(parentComponent)) {
    component._parentComponent = parentComponent
  }
  if (isFunction(component.componentWillMount)) {
    errorCatcher(() => {
      (component as any).componentWillMount()
    }, component)
    component.state = component.getState()
  }
  component._dirty = false
  const rendered = renderComponent(component)
  component._rendered = rendered
  if (isFunction(component.componentDidMount)) {
    readyComponents.push(component)
  }
  if (!isNullOrUndef(ref)) {
    readyComponents.push(() => Ref.attach(vnode, ref, component.dom))
  }
  const dom = (vnode.dom = component.dom = mountVNode(
    rendered,
    getChildContext(component, parentContext),
    component
  ) as Element)
  component._disable = false
  return dom
}

export function updateComponent (component, isForce = false) {
  const lastDom = component.dom
  const props = component.props
  const state = component.getState()
  const context = component.context
  const prevProps = component.prevProps || props
  const prevState = component.prevState || state
  const prevContext = component.prevContext || context
  component.props = prevProps
  component.context = prevContext
  let skip = false
  if (
    !isForce &&
    isFunction(component.shouldComponentUpdate) &&
    component.shouldComponentUpdate(props, state, context) === false
  ) {
    skip = true
  } else if (isFunction(component.componentWillUpdate)) {
    errorCatcher(() => {
      component.componentWillUpdate(props, state, context)
    }, component)
  }
  component.props = props
  component.state = state
  component.context = context
  component._dirty = false
  if (!skip) {
    const lastRendered = component._rendered
    const rendered = renderComponent(component)
    const childContext = getChildContext(component, context)
    component.dom = patch(lastRendered, rendered, lastDom, childContext)
    component._rendered = rendered
    if (isFunction(component.componentDidUpdate)) {
      errorCatcher(() => {
        component.componentDidUpdate(prevProps, prevState, context)
      }, component)
    }
  }
  component.prevProps = component.props
  component.prevState = component.state
  component.prevContext = component.context
  if (component._pendingCallbacks) {
    while (component._pendingCallbacks.length) {
      component._pendingCallbacks.pop().call(component)
    }
  }
  flushMount()
}

function createElement<T> (
  type: string | Function | Component<any, any>,
  properties?: T & Props | null,
  ..._children: Array<VirtualChildren | null>
) {
  let children: any = _children
  if (_children) {
    if (_children.length === 1) {
      children = _children[0]
    } else if (_children.length === 0) {
      children = undefined
    }
  }
  let props
  if (isString(type)) {
    props = transformPropsForRealTag(type, properties as Props)
    props.owner = CurrentOwner.current
    return h(type, props, children as any) as VNode
  } else if (isFunction(type)) {
    props = transformPropsForComponent(
      properties as any,
      (type as any).defaultProps
    )
    if (!props.children) {
      props.children = children || EMPTY_CHILDREN
    }
    props.owner = CurrentOwner.current
    return type.prototype && type.prototype.render
      ? new FullComponent(type, props)
      : new StatelessComponent(type, props)
  }
  return type
}

 queue.forEach((item) => {
   if (isFunction(item)) {
     item()
   } else if (item.componentDidMount) {
     errorCatcher(() => {
       item.componentDidMount()
     }, item)
   }
 })

export function attachEvent (
  domNode: Element,
  eventName: string,
  handler: Function
) {
  eventName = fixEvent(domNode, eventName)
  /* istanbul ignore next */
  if (eventName === ONPROPERTYCHANGE) {
    processOnPropertyChangeEvent(domNode, handler)
    return
  }
  let delegatedRoots = delegatedEvents.get(eventName)
  if (unbubbleEvents[eventName] === 1) {
    if (!delegatedRoots) {
      delegatedRoots = new MapClass()
    }
    const event = attachEventToNode(domNode, eventName, delegatedRoots)
    delegatedEvents.set(eventName, delegatedRoots)
    if (isFunction(handler)) {
      delegatedRoots.set(domNode, {
        eventHandler: handler,
        event
      })
    }
  } else {
    if (!delegatedRoots) {
      delegatedRoots = {
        items: new MapClass()
      }
      delegatedRoots.event = attachEventToDocument(
        doc,
        eventName,
        delegatedRoots
      )
      delegatedEvents.set(eventName, delegatedRoots)
    }
    if (isFunction(handler)) {
      delegatedRoots.items.set(domNode, handler)
    }
  }
}

function patchEvent (
  eventName: string,
  lastEvent: Function,
  nextEvent: Function,
  domNode: Element
) {
  if (lastEvent !== nextEvent) {
    if (isFunction(lastEvent)) {
      detachEvent(domNode, eventName, lastEvent)
    }
    attachEvent(domNode, eventName, nextEvent)
  }
}

export function unmountComponent (vnode: FullComponent) {
  const component = vnode.component
  if (isFunction(component.componentWillUnmount)) {
    errorCatcher(() => {
      (component as any).componentWillUnmount()
    }, component)
  }
  component._disable = true
  unmount(component._rendered)
  if (!isNullOrUndef(vnode.props.ref)) {
    Ref.detach(vnode, vnode.props.ref, vnode.dom as any)
  }
}

/* istanbul ignore next */
function propertyChangeHandler (event) {
  if (event.propertyName !== 'value') {
    return
  }
  const target = event.target || event.srcElement
  const val = target.value
  if (val === propertyChangeActiveElementValue) {
    return
  }
  propertyChangeActiveElementValue = val
  if (isFunction(propertyChangeActiveHandler)) {
    propertyChangeActiveHandler.call(target, event)
  }
}

export function reRenderComponent (prev: CompositeComponent, current: CompositeComponent) {
  const component = (current.component = prev.component)
  const nextProps = current.props
  const nextContext = component.context
  component._disable = true
  if (isFunction(component.componentWillReceiveProps)) {
    errorCatcher(() => {
      (component as any).componentWillReceiveProps(nextProps, nextContext)
    }, component)
  }
  component._disable = false
  component.prevProps = component.props
  component.prevState = component.state
  component.prevContext = component.context
  component.props = nextProps
  component.context = nextContext
  if (!isNullOrUndef(nextProps.ref)) {
    Ref.update(prev, current)
  }
  updateComponent(component)
  return component.dom
}

function errorHandler (component: Component<any, any>, error) {
  let boundary

  while (true) {
    if (isFunction(component.componentDidCatch)) {
      boundary = component
      break
    } else if (component._parentComponent) {
      component = component._parentComponent
    } else {
      break
    }
  }

  if (boundary) {
    const _disable = boundary._disable
    boundary._disable = false
    boundary.componentDidCatch(error)
    boundary._disable = _disable
  } else {
    throw error
  }
}