wip: restructure api + support watch multiple sources

packages/runtime-core/src/apiLifecycle.ts

@@ -0,0 +1,54 @@
+import { ComponentInstance, LifecycleHooks, currentInstance } from './component'
+
+function injectHook(
+  name: keyof LifecycleHooks,
+  hook: () => void,
+  target: ComponentInstance | null | void = currentInstance
+) {
+  if (target) {
+    // TODO inject a error-handling wrapped version of the hook
+    // TODO also set currentInstance when calling the hook
+    ;(target[name] || (target[name] = [])).push(hook)
+  } else {
+    // TODO warn
+  }
+}
+
+export function onBeforeMount(hook: () => void, target?: ComponentInstance) {
+  injectHook('bm', hook, target)
+}
+
+export function onMounted(hook: () => void, target?: ComponentInstance) {
+  injectHook('m', hook, target)
+}
+
+export function onBeforeUpdate(hook: () => void, target?: ComponentInstance) {
+  injectHook('bu', hook, target)
+}
+
+export function onUpdated(hook: () => void, target?: ComponentInstance) {
+  injectHook('u', hook, target)
+}
+
+export function onBeforeUnmount(hook: () => void, target?: ComponentInstance) {
+  injectHook('bum', hook, target)
+}
+
+export function onUnmounted(hook: () => void, target?: ComponentInstance) {
+  injectHook('um', hook, target)
+}
+
+export function onRenderTriggered(
+  hook: () => void,
+  target?: ComponentInstance
+) {
+  injectHook('rtg', hook, target)
+}
+
+export function onRenderTracked(hook: () => void, target?: ComponentInstance) {
+  injectHook('rtc', hook, target)
+}
+
+export function onErrorCaptured(hook: () => void, target?: ComponentInstance) {
+  injectHook('ec', hook, target)
+}