[add][dom缓存]

src/uilts/help.js

@@ -224,8 +224,36 @@ export function checkURL(URL) {
   var Expression = /http(s)?:\/\/([\w-]+\.)+[\w-]+(\/[\w- .\/?%&=]*)?/;
   var objExp = new RegExp(Expression);
   if (objExp.test(str) == true) {
-      return true;
+    return true;
   } else {
-      return false;
+    return false;
   }
 }
+
+let $_data = []
+export function $(key, cache = true) {
+  if (!key) {
+    return
+  }
+  // 不使用缓存
+  if (!cache) {
+    return document.querySelector(key)
+  }
+
+  let _dom
+  for (let i in $_data) {
+    if ($_data[i].key == key) {
+      _dom = $_data[i].element
+      break
+    }
+  }
+
+  // 没有缓存
+  if (!_dom) {
+    _dom = document.querySelector(key)
+    if (_dom) {
+      $_data.push({ key, element: _dom })
+    }
+  }
+  return _dom
+}