问题描述

我有以下带有关系的 Eloquent 模型:

I have the following Eloquent Models with relationships:

class Lead extends Model 
{
    public function contacts() 
    {
        return $this->belongsToMany('AppContact')
                    ->withPivot('is_primary');
    }
}

class Contact extends Model 
{
    public function leads() 
    {
        return $this->belongsToMany('AppLead')
                    ->withPivot('is_primary');
    }
}

数据透视表包含一个附加参数 (is_primary)，用于将关系标记为主要关系.目前，我在查询联系人时看到这样的返回:

The pivot table contains an additional param (is_primary) that marks a relationship as the primary. Currently, I see returns like this when I query for a contact:

{
    "id": 565,
    "leads": [
        {
            "id": 349,
             "pivot": {
                "contact_id": "565",
                "lead_id": "349",
                "is_primary": "0"
             }
        }
    ]
}

有没有办法将其中的 is_primary 转换为布尔值?我已经尝试将它添加到两个模型的 $casts 数组中，但这并没有改变任何东西.

Is there a way to cast the is_primary in that to a boolean? I've tried adding it to the $casts array of both models but that did not change anything.

推荐答案

由于这是数据透视表上的一个属性，因此使用 $casts 属性将不适用于 Lead 或 Contact 模型.

Since this is an attribute on the pivot table, using the $casts attribute won't work on either the Lead or Contact model.

但是，您可以尝试的一件事是使用自定义 Pivot 模型并定义了 $casts 属性.自定义数据透视模型的文档位于此处.基本上，您使用自定义创建一个新的 Pivot 模型，然后更新 Lead 和 Contact 模型以使用此自定义 Pivot 模型而不是基础模型.

One thing you can try, however, is to use a custom Pivot model with the $casts attribute defined. Documentation on custom pivot models is here. Basically, you create a new Pivot model with your customizations, and then update the Lead and the Contact models to use this custom Pivot model instead of the base one.

首先，创建您的自定义 Pivot 模型，它扩展了基本的 Pivot 模型:

First, create your custom Pivot model which extends the base Pivot model:

<?php namespace App;

use IlluminateDatabaseEloquentRelationsPivot;

class PrimaryPivot extends Pivot {
    protected $casts = ['is_primary' => 'boolean'];
}

现在，覆盖 Lead 和 Contact 模型上的 newPivot() 方法:

Now, override the newPivot() method on the Lead and the Contact models:

class Lead extends Model {
    public function newPivot(Model $parent, array $attributes, $table, $exists) {
        return new AppPrimaryPivot($parent, $attributes, $table, $exists);
    }
}

class Contact extends Model {
    public function newPivot(Model $parent, array $attributes, $table, $exists) {
        return new AppPrimaryPivot($parent, $attributes, $table, $exists);
    }
}

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