From 3ead2f402724b3c23fc9c26354fc71e73e93dac0 Mon Sep 17 00:00:00 2001
From: chenjiahan <chenjiahan@youzan.com>
Date: Fri, 25 Sep 2020 11:05:26 +0800
Subject: [PATCH] feat: add useRelation composition

---
 src/composition/use-relation.ts | 114 +++++++++++++++++++++++++++++---
 1 file changed, 103 insertions(+), 11 deletions(-)

diff --git a/src/composition/use-relation.ts b/src/composition/use-relation.ts
index 53c47b2b9..e9cd8f15a 100644
--- a/src/composition/use-relation.ts
+++ b/src/composition/use-relation.ts
@@ -1,25 +1,117 @@
-import { VNode, isVNode, VNodeNormalizedChildren } from 'vue';
+import {
+  VNode,
+  inject,
+  isVNode,
+  provide,
+  computed,
+  reactive,
+  onUnmounted,
+  getCurrentInstance,
+  VNodeNormalizedChildren,
+  ComponentPublicInstance as PublicInstance,
+  ComponentInternalInstance as InternalInstance,
+} from 'vue';
 
 export function flattenVNodes(children: VNodeNormalizedChildren) {
   const result: VNode[] = [];
 
   const traverse = (children: VNodeNormalizedChildren) => {
-    if (!Array.isArray(children)) {
-      return;
-    }
+    if (Array.isArray(children)) {
+      children.forEach((child) => {
+        if (isVNode(child)) {
+          result.push(child);
 
-    children.forEach((child) => {
-      if (isVNode(child)) {
-        result.push(child);
+          if (child.component?.subTree) {
+            traverse(child.component.subTree.children);
+          }
 
-        if (child.children) {
-          traverse(child.children);
+          if (child.children) {
+            traverse(child.children);
+          }
         }
-      }
-    });
+      });
+    }
   };
 
   traverse(children);
 
   return result;
 }
+
+// sort children instances by vnodes order
+export function sortChildren(
+  parent: InternalInstance,
+  publicChildren: PublicInstance[],
+  internalChildren: InternalInstance[]
+) {
+  const vnodes = flattenVNodes(parent.subTree.children);
+
+  internalChildren.sort(
+    (a, b) => vnodes.indexOf(a.vnode) - vnodes.indexOf(b.vnode)
+  );
+
+  const orderedPublicChildren = internalChildren.map((item) => item.proxy!);
+
+  publicChildren.sort((a, b) => {
+    const indexA = orderedPublicChildren.indexOf(a);
+    const indexB = orderedPublicChildren.indexOf(b);
+    return indexA - indexB;
+  });
+}
+
+export function useChildren(key: string) {
+  const publicChildren: PublicInstance[] = reactive([]);
+  const internalChildren: InternalInstance[] = reactive([]);
+  const parent = getCurrentInstance()!;
+
+  const linkChildren = (value: any) => {
+    const link = (child: InternalInstance) => {
+      if (child.proxy) {
+        internalChildren.push(child);
+        publicChildren.push(child.proxy);
+        sortChildren(parent, publicChildren, internalChildren);
+      }
+    };
+
+    const unlink = (child: InternalInstance) => {
+      const index = internalChildren.indexOf(child);
+      publicChildren.splice(index, 1);
+      internalChildren.splice(index, 1);
+    };
+
+    provide(key, {
+      link,
+      unlink,
+      children: publicChildren,
+      internalChildren,
+      ...value,
+    });
+  };
+
+  return {
+    children: publicChildren,
+    linkChildren,
+  };
+}
+
+export function useParent(key: string) {
+  const parent = inject<any | null>(key, null);
+
+  if (parent) {
+    const instance = getCurrentInstance();
+    const index = computed(() => parent.internalChildren.indexOf(instance));
+
+    parent.link(instance);
+
+    onUnmounted(() => {
+      parent.unlink(instance);
+    });
+
+    return {
+      parent,
+      index,
+    };
+  }
+
+  return {};
+}