feat(nvue): useNvueEvent

packages/uni-components/src/helpers/useNvueEvent.ts

+import { Ref, SetupContext, EmitsOptions } from 'vue'
+
+type EventDetail = Record<string, any>
+type WeexTarget = WechatMiniprogram.BaseEvent['target']
+export type CustomEventTrigger = ReturnType<typeof useCustomEvent>
+export type EmitEvent<E extends (...args: any) => any> = [Parameters<E>[0]]
+
+export function useCustomEvent<E extends EmitsOptions>(
+  ref: Ref<HTMLElement | null>,
+  emit: SetupContext<E>['emit']
+) {
+  return (name: string, detail?: EventDetail) => {
+    if (ref.value) {
+      emit(name, normalizeCustomEvent(name, ref.value, detail || {}))
+    }
+  }
+}
+
+function normalizeCustomEvent(
+  name: string,
+  target: WeexTarget,
+  detail: EventDetail = {}
+): WechatMiniprogram.CustomEvent {
+  target = processTarget(target)
+  return {
+    type: name,
+    timeStamp: Date.now(),
+    target,
+    currentTarget: target,
+    detail,
+  }
+}
+
+function cached(fn: Function) {
+  const cache = Object.create(null)
+  return function cachedFn(str: string) {
+    const hit = cache[str]
+    return hit || (cache[str] = fn(str))
+  }
+}
+
+const firstLetterToLowerCase = cached((str: string) => {
+  return str.charAt(0).toLowerCase() + str.slice(1)
+})
+
+function processTarget(weexTarget: WeexTarget): WeexTarget {
+  const { offsetLeft, offsetTop } = weexTarget
+  const attr = (weexTarget as any).attr
+
+  const dataset: Record<string, any> = {}
+  Object.keys(attr || {}).forEach((key) => {
+    if (key.indexOf('data') === 0) {
+      dataset[firstLetterToLowerCase(key.replace('data', ''))] = attr[key]
+    }
+  })
+
+  return {
+    id: (attr && attr.id) || '',
+    dataset,
+    offsetLeft: offsetLeft || 0,
+    offsetTop: offsetTop || 0,
+  }
+}