Add exception prompt

src/mixin/autoResize.js

@@ -32,8 +32,14 @@ export default {
         $nextTick(e => {
           const dom = this.dom = $refs[ref]
 
-          this.width = dom.clientWidth
+          this.width = dom ? dom.clientWidth : 0
-          this.height = dom.clientHeight
+          this.height = dom ? dom.clientHeight : 0
+
+          if (!dom) {
+            console.warn('DataV: Failed to get dom node, component rendering may be abnormal!')
+          } else if (!this.width || !this.height) {
+            console.warn('DataV: Component width or height is 0px, rendering abnormality may occur!')
+          }
 
           if (typeof onResize === 'function' && resize) onResize()
 
@@ -56,6 +62,8 @@ export default {
     unbindDomResizeCallback () {
       let { domObserver, debounceInitWHFun } = this
 
+      if (!domObserver) return
+
       domObserver.disconnect()
       domObserver.takeRecords()
       domObserver = null