chore: move mixins

src-next/mixins/relation.js

@@ -0,0 +1,69 @@
+import { sortChildren } from '../utils/vnodes';
+
+export function ChildrenMixin(parent, options = {}) {
+  const indexKey = options.indexKey || 'index';
+
+  return {
+    inject: {
+      // TODO: disableBindRelation
+      parent: {
+        from: parent,
+        default: null,
+      },
+    },
+
+    computed: {
+      [indexKey]() {
+        this.bindRelation();
+
+        if (this.parent) {
+          return this.parent.children.indexOf(this);
+        }
+
+        return null;
+      },
+    },
+
+    mounted() {
+      this.bindRelation();
+    },
+
+    beforeDestroy() {
+      if (this.parent) {
+        this.parent.children = this.parent.children.filter(
+          (item) => item !== this
+        );
+      }
+    },
+
+    methods: {
+      bindRelation() {
+        if (!this.parent || this.parent.children.indexOf(this) !== -1) {
+          return;
+        }
+
+        const children = [...this.parent.children, this];
+
+        sortChildren(children, this.parent);
+
+        this.parent.children = children;
+      },
+    },
+  };
+}
+
+export function ParentMixin(parent) {
+  return {
+    provide() {
+      return {
+        [parent]: this,
+      };
+    },
+
+    data() {
+      return {
+        children: [],
+      };
+    },
+  };
+}