購物車流程

1.創(chuàng)建購物車頁面仿吞，模型，控制器蛹尝，數(shù)據(jù)庫
數(shù)據(jù)表結(jié)構(gòu)如下

CREATE TABLE cart (
id int(11) NOT NULL AUTO_INCREMENT,
goods_id int(11) NOT NULL,
goods_num int(11) NOT NULL,
user_id int(11) NOT NULL,
status tinyint(1) NOT NULL,
create_time int(10) NOT NULL,
PRIMARY KEY (id)
) ENGINE=InnoDB AUTO_INCREMENT=4 DEFAULT CHARSET=utf8;

2.代碼流程
首先獲取頁面?zhèn)鬏斶^來的數(shù)據(jù)

$data = Yii::$app->request->post();

然后判斷用戶是否登錄

if (Yii::$app->user->isGuest)

如果未登錄則將購物車數(shù)據(jù)保存到cookie當中

 //調(diào)用此方法將購物數(shù)據(jù)寫入到cookie（在頁面顯示之前沒有真實的寫入）
    $this->cartToCookie($data);

    //從cookie中獲取數(shù)據(jù)在頁面顯示（剛剛提交的數(shù)據(jù)并不能獲取到）
    $cookieCart = Yii::$app->request->cookies->getValue('frontend_cookie');

    //1 獲取cookie中的所有購物車數(shù)據(jù)
    $carts = unserialize($cookieCart);

    //3 將接收數(shù)據(jù)和cookie中讀取的數(shù)據(jù)合并
    if (isset($carts[$data['goods_id']])) {
        $carts[$data['goods_id']] += $data['num'];
    }else{
        $carts[$data['goods_id']] = $data['num'];
    }

    //2 獲取goods_id在購物車中的所有的商品數(shù)據(jù)
    $goodsIdArr = array_keys($carts);
    $goods = Goods::findAll($goodsIdArr);

如果用戶已經(jīng)登錄擅憔，則將購物車數(shù)據(jù)寫入進數(shù)據(jù)庫

//1 查詢出購物車中當前用戶待支付的購物車數(shù)據(jù)
   $cartGoods = Cart::find()
       ->where(['goods_id' => $data['goods_id'], 'user_id'=>Yii::$app->user->identity->id, 'status'=>2])
       ->one();

   //2 如果數(shù)據(jù)庫中的待支付數(shù)據(jù)為空直接寫入當前數(shù)據(jù)
   if (empty($cartGoods)) {
       $cartModel = new Cart();
       $cartModel->goods_id = $data['goods_id'];
       $cartModel->goods_num = $data['num'];
       $cartModel->user_id = Yii::$app->user->identity->id;
       $cartModel->status = 2;
       $cartModel->create_time = time();
       if ($cartModel->save() === false) {
           echo '加入購物車失敗';
           exit;
       }
   }else{
       //3 如果不為空則將新添加的數(shù)據(jù)更新到當前商品
       $cartGoods->goods_num += $data['num'];
       if ($cartGoods->save() === false) {
           echo '加入購物車失敗';
           exit;
       }

   }

   //4 查詢出用戶所有待支付購物車數(shù)據(jù)
   $mysqlCart = Cart::find()
       ->where(['user_id'=>Yii::$app->user->identity->id, 'status'=>2])
       ->asArray()->all();

   $goods = [];
   $carts = [];

   //5 構(gòu)造和cookie相同的數(shù)據(jù)結(jié)構(gòu)
   if (!empty($mysqlCart)) {
       foreach($mysqlCart as $v){
           $carts[$v['goods_id']] = $v['goods_num'];
       }

       $goods = Goods::findAll(array_keys($carts));
   }
}

最后將數(shù)據(jù)返回到頁面當中

return $this->render('cart', [
        'goods' => $goods,
        'carts' => $carts
    ]);