refactor(template-ref): improve template ref handling

close #836, close #839

packages/runtime-core/__tests__/apiTemplateRef.spec.ts

@@ -22,9 +22,7 @@ describe('api: template refs', () => {
         }
       },
       render() {
-        // Note: string refs are compiled into [ctx, key] tuples by the compiler
-        // to ensure correct context.
-        return h('div', { ref: [this, 'refKey'] as any })
+        return h('div', { ref: 'refKey' })
       }
     }
     render(h(Comp), root)
@@ -45,7 +43,7 @@ describe('api: template refs', () => {
         }
       },
       render() {
-        return h('div', { ref: [this, refKey.value] as any })
+        return h('div', { ref: refKey.value })
       }
     }
     render(h(Comp), root)
@@ -70,7 +68,7 @@ describe('api: template refs', () => {
         }
       },
       render() {
-        return toggle.value ? h('div', { ref: [this, 'refKey'] as any }) : null
+        return toggle.value ? h('div', { ref: 'refKey' }) : null
       }
     }
     render(h(Comp), root)
@@ -178,4 +176,28 @@ describe('api: template refs', () => {
     await nextTick()
     expect(el.value).toBe(null)
   })
+
+  test('string ref inside slots', async () => {
+    const root = nodeOps.createElement('div')
+    const spy = jest.fn()
+    const Child = {
+      render(this: any) {
+        return this.$slots.default()
+      }
+    }
+
+    const Comp = {
+      render() {
+        return h(Child, () => {
+          return h('div', { ref: 'foo' })
+        })
+      },
+      mounted(this: any) {
+        spy(this.$refs.foo.tag)
+      }
+    }
+    render(h(Comp), root)
+
+    expect(spy).toHaveBeenCalledWith('div')
+  })
 })

packages/runtime-core/src/renderer.ts

@@ -8,7 +8,8 @@ import {
   VNodeArrayChildren,
   createVNode,
   isSameVNodeType,
-  Static
+  Static,
+  VNodeNormalizedRef
 } from './vnode'
 import {
   ComponentInternalInstance,
@@ -30,8 +31,7 @@ import {
   isFunction,
   PatchFlags,
   ShapeFlags,
-  NOOP,
-  isArray
+  NOOP
 } from '@vue/shared'
 import {
   queueJob,
@@ -44,7 +44,6 @@ import {
   stop,
   ReactiveEffectOptions,
   isRef,
-  Ref,
   toRaw,
   DebuggerEvent
 } from '@vue/reactivity'
@@ -1789,21 +1788,22 @@ function baseCreateRenderer<
   }
 
   const setRef = (
-    ref: string | Function | Ref | [ComponentPublicInstance, string],
-    oldRef: string | Function | Ref | [ComponentPublicInstance, string] | null,
+    rawRef: VNodeNormalizedRef,
+    oldRawRef: VNodeNormalizedRef | null,
     parent: ComponentInternalInstance,
     value: HostNode | ComponentPublicInstance | null
   ) => {
-    if (isArray(ref)) {
-      // template string refs are compiled into tuples like [ctx, key] to
-      // ensure refs inside slots are set on the correct owner instance.
-      const [{ $: owner }, key] = ref
-      setRef(key, oldRef && (oldRef as any[])[1], owner, value)
+    const [owner, ref] = rawRef
+    if (__DEV__ && !owner) {
+      warn(
+        `Missing ref owner context. ref cannot be used on hoisted vnodes. ` +
+          `A vnode with ref must be created inside the render function.`
+      )
       return
     }
-
-    const refs = parent.refs === EMPTY_OBJ ? (parent.refs = {}) : parent.refs
-    const renderContext = toRaw(parent.renderContext)
+    const oldRef = oldRawRef && oldRawRef[1]
+    const refs = owner.refs === EMPTY_OBJ ? (owner.refs = {}) : owner.refs
+    const renderContext = toRaw(owner.renderContext)
 
     // unset old ref
     if (oldRef !== null && oldRef !== ref) {
@@ -1827,7 +1827,7 @@ function baseCreateRenderer<
     } else if (isRef(ref)) {
       ref.value = value
     } else if (isFunction(ref)) {
-      callWithErrorHandling(ref, parent, ErrorCodes.FUNCTION_REF, [value])
+      callWithErrorHandling(ref, parent, ErrorCodes.FUNCTION_REF, [value, refs])
     } else if (__DEV__) {
       warn('Invalid template ref type:', value, `(${typeof value})`)
     }

packages/runtime-core/src/vnode.ts

@@ -52,10 +52,17 @@ export type VNodeTypes =
   | typeof PortalImpl
   | typeof SuspenseImpl
 
+export type VNodeRef =
+  | string
+  | Ref
+  | ((ref: object | null, refs: Record<string, any>) => void)
+
+export type VNodeNormalizedRef = [ComponentInternalInstance, VNodeRef]
+
 export interface VNodeProps {
   [key: string]: any
   key?: string | number
-  ref?: string | Ref | ((ref: object | null) => void)
+  ref?: VNodeRef
 
   // vnode hooks
   onVnodeBeforeMount?: (vnode: VNode) => void
@@ -95,7 +102,7 @@ export interface VNode<HostNode = any, HostElement = any> {
   type: VNodeTypes
   props: VNodeProps | null
   key: string | number | null
-  ref: string | Ref | ((ref: object | null) => void) | null
+  ref: VNodeNormalizedRef | null
   scopeId: string | null // SFC only
   children: VNodeNormalizedChildren<HostNode, HostElement>
   component: ComponentInternalInstance | null
@@ -261,7 +268,10 @@ export function createVNode(
     type,
     props,
     key: props !== null && props.key !== undefined ? props.key : null,
-    ref: (props !== null && props.ref) || null,
+    ref:
+      props !== null && props.ref !== undefined
+        ? [currentRenderingInstance!, props.ref]
+        : null,
     scopeId: currentScopeId,
     children: null,
     component: null,