From 05be8d9664a09639f672ac4aaa13c66c69aa6df7 Mon Sep 17 00:00:00 2001
From: yunwuxin <448901948@qq.com>
Date: Thu, 23 Mar 2017 17:45:15 +0800
Subject: [PATCH] =?UTF-8?q?belongsToMany=E5=A2=9E=E5=8A=A0=E6=95=B0?=
 =?UTF-8?q?=E6=8D=AE=E5=90=8C=E6=AD=A5=E6=96=B9=E6=B3=95?=
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---
 .../think/model/relation/BelongsToMany.php    | 51 ++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/library/think/model/relation/BelongsToMany.php b/library/think/model/relation/BelongsToMany.php
index 026334ed..d684fa23 100644
--- a/library/think/model/relation/BelongsToMany.php
+++ b/library/think/model/relation/BelongsToMany.php
@@ -121,7 +121,7 @@ class BelongsToMany extends Relation
     public function getRelation($subRelation = '', $closure = null)
     {
         if ($closure) {
-            call_user_func_array($closure, [ & $this->query]);
+            call_user_func_array($closure, [& $this->query]);
         }
         $result = $this->buildQuery()->relation($subRelation)->select();
         $this->hydratePivot($result);
@@ -503,6 +503,55 @@ class BelongsToMany extends Relation
         }
     }
 
+    /**
+     * 数据同步
+     * @param array $ids
+     * @param bool  $detaching
+     * @return array
+     */
+    public function sync($ids, $detaching = true)
+    {
+        $changes = [
+            'attached' => [],
+            'detached' => [],
+            'updated'  => []
+        ];
+        $pk      = $this->parent->getPk();
+        $current = $this->pivot->where($this->localKey, $this->parent->$pk)
+            ->column($this->foreignKey);
+        $records = [];
+
+        foreach ($ids as $key => $value) {
+            if (!is_array($value)) {
+                $records[$value] = [];
+            } else {
+                $records[$key] = $value;
+            }
+        }
+
+        $detach = array_diff($current, array_keys($records));
+
+        if ($detaching && count($detach) > 0) {
+            $this->detach($detach);
+
+            $changes['detached'] = $detach;
+        }
+
+        foreach ($records as $id => $attributes) {
+            if (!in_array($id, $current)) {
+                $this->attach($id, $attributes);
+                $changes['attached'][] = $id;
+            } elseif (count($attributes) > 0 &&
+                $this->attach($id, $attributes)
+            ) {
+                $changes['updated'][] = $id;
+            }
+        }
+
+        return $changes;
+
+    }
+
     /**
      * 执行基础查询（进执行一次）
      * @access protected