Laravel - 雄辩：与命名空间的多态关系 [英] Laravel - Eloquent: Polymorphic relations with namespace

问题描述

我的情况是：一个日历属于一个客户或推销员

由于我也有类，如事件和文件，我使用命名空间App \Models为所有我的模型类。

所以我设置了多态关系：

在Calender.php

  public function user（）{
 return $ this-> morphTo（）; 
} 
  

在Customer.php和Salesman.php

  public function calendars（）{
 return $ this-> morphMany（'App \Models\Calendar'，'user'）; 
} 
  

现在我做

  $ calendar = Calendar :: find（1）; //销售员的日历
 $ calendar-> user; //错误这里
 ... 
  

我收到此错误消息：

  Symfony \ Component \ Debug \ Exception \ FatalErrorException 
找不到'salesman'
  

我注意到，'salesman'低套，也许这是问题？这是我从Laravels堆栈跟踪获得的这个

$ b

打开：/ var / www / cloudcube / vendor /laravel/framework/src/Illuminate/Database/Eloquent/Model.php

  //使用名称为关系函数，其中
 //与_id组合时应通常匹配列。 
 if（is_null（$ foreignKey））
 {
 $ foreignKey = snake_case（$ relation）.'_ id'; 
} 
 
 $ instance = new $ related; // HIGHLIGHTED 
  

我在这行之间有一个类似的错误，当我搞砸命名空间时，所以我想这是有关系的。有什么办法可以告诉 morphTo（）方法来使用正确的命名空间吗？还是发现这个问题？

还是发现这个问题吗？让它工作：
与命名空间的多态雄辩关系

解决方案

我找到了一个适合我的解决方案。

我始终定义与正确的命名空间，例如在日历中：

public function events（）{
return $ this-> hasMany \\Models\Event'）;
}

我的问题由2个并发症组成：

1. $ calendar-> user（）与 morphTo（...）函数不起作用，因为我的模型是在一个命名空间，而 morphTo（...）没有办法给这个命名空间。




2. $ salesman-> calenders（） - > get（）返回和空列表，尽管我在数据库中的关系在那里。我发现这是因为与查询的绑定。

解决方案1.：编写自定义 morphTo（...）在日历中覆盖Laravel之一的函数。我使用Laravels的来源 morphTo（...）作为基础。这个函数的最终语句是 return $ this-> belongsTo（$ class，$ id）;
有 $ class 必须是命名空间的类名。我使用基本的字符串操作将其关闭。

解决方案2.：编写自定义 morphMany（...）函数，并让它返回一个 MyMorphMany（...）类似于

这里的问题是 $ query 传递给 MyMorphMany 构造函数具有错误（命名空间）绑定。它将寻找其中user_type =App \\Models\\\Salesman。

修复这个我在 MyMorphMany 中使用了一个定制的 getResults（）函数，它覆盖了默认的Laravels实现，我改变了绑定使用正确的，没有命名空间的下层，类名。然后我在 MyMorphMany的 get（）函数中调用这个 getResults（） / code> class

我使用 $ query-> getBindings（）和 $ query-> setBindings（）以更正绑定。

希望这可以节省别人几天的工作，像它会救我：）

My situation is: a Calendar belongs to a Customer or Salesman

Because I also have classes like Event and File, I used the namespace App\Models for all my model classes.

so I set up the polymorphic relation:

in Calender.php

public function user() {
    return $this->morphTo();
}

in Customer.php and Salesman.php

public function calendars() {
    return $this->morphMany('App\Models\Calendar', 'user');
}

Now when i do

$calendar= Calendar::find(1); //calendar from a salesman
$calendar->user; //error here
...

I get this error message:

Symfony \ Component \ Debug \ Exception \ FatalErrorException
Class 'salesman' not found

I noticed that 'salesman' is low cased, maybe this is the problem?

and this is what I get from Laravels stacktrace

open: /var/www/cloudcube/vendor/laravel/framework/src/Illuminate/Database/Eloquent/Model.php

// foreign key name by using the name of the relationship function, which
// when combined with an "_id" should conventionally match the columns.
if (is_null($foreignKey))
{
    $foreignKey = snake_case($relation).'_id';
}

$instance = new $related; //HIGHLIGHTED

I had a similar error before on this line, when I was messing with the namespaces, so I guess it has something to do with that. Is there any way I can tell the morphTo() method to use the correct namespace?

Or is it something else causing this issue?

Also found this solution, but can't seem to get it working: Polymorphic Eloquent relationships with namespaces

解决方案

I found a solution that worked for me.

I always define relationships with the correct namespace, for example in Calendar:

public function events() { return $this->hasMany('App\Models\Event'); }

My problem consisted out of 2 complications:

1. $calendar->user() with the morphTo(...) function was not working because my models were in a namespace, and morphTo(...) had no way of giving this namespace.

2. $salesman->calenders()->get() returned and empty list, although my relations in the database were there. I found out this is because of bindings with the query.

Solution for 1. : Writing a custom morphTo(...) function in Calendar to override the one of Laravel. I used the source of Laravels morphTo(...) as a base. The final statement of this function is return $this->belongsTo($class, $id); There $class must be the namespaced class name. I used basic string operations to pull that off.

Solution for 2. : Writing a custom morphMany(...) function in Salesman and letting it return a MyMorphMany(...) similar to what Polymorphic Eloquent relationships with namespaces described.

The problem here is that $query that is passed to the MyMorphMany constructor has the wrong (namespaced) binding. It will look for where user_type = "App\\Models\\Salesman".

To fix this I used a custom getResults() function in MyMorphMany which overrides the default Laravels implementation, there I changed the bindings to use the correct, un-namespaced lower cased, class name. Then I called this getResults() function in the get() function of the MyMorphMany class.

I used $query->getBindings() and $query->setBindings() to correct the bindings.

Hope this saves someone else a few days of work, like it would have saved me :)

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