[improvement] Tabs: use relation mixin

packages/tab/index.js

@@ -1,11 +1,11 @@
 /* eslint-disable object-shorthand */
 import { use } from '../utils';
-import { FindParentMixin } from '../mixins/find-parent';
+import { ChildrenMixin } from '../mixins/relation';
 
 const [sfc, bem] = use('tab');
 
 export default sfc({
-  mixins: [FindParentMixin],
+  mixins: [ChildrenMixin('vanTabs')],
 
   props: {
     title: String,
@@ -19,10 +19,6 @@ export default sfc({
   },
 
   computed: {
-    index() {
-      return this.parent.tabs.indexOf(this);
-    },
-
     selected() {
       return this.index === this.parent.curActive;
     }
@@ -38,24 +34,12 @@ export default sfc({
     }
   },
 
-  created() {
-    this.findParent('van-tabs');
-  },
-
   mounted() {
-    const { tabs } = this.parent;
-    const index = this.parent.slots().indexOf(this.$vnode);
-    tabs.splice(index === -1 ? tabs.length : index, 0, this);
-
     if (this.slots('title')) {
       this.parent.renderTitle(this.$refs.title, this.index);
     }
   },
 
-  beforeDestroy() {
-    this.parent.tabs.splice(this.index, 1);
-  },
-
   render(h) {
     const { slots } = this;
     const shouldRender = this.inited || !this.parent.lazyRender;