php – Laravel 5.1和Fractal：包括变压器上的数据透视表数据

表：联系人,公司和具有自定义透视属性的关系表company_contact(company_id,contact_id,is_main)

公司和联系人有多对多的关系(属于两个型号).

检索公司联系人时的预期输出：

{
    "data": [
        {
            "id": 1,
            "name": "JohnDoe",
            "is_main": false
        },
        {
            "id": 2,
            "name": "JaneDoe",
            "is_main": true
        }
    ]
}

使用？include = companies检索联系人列表时的预期输出：

{
    "data": [
        {
            "id": 1,
            "name": "John Doe",
            "companies": {
                "data": [
                    {
                        "id": 501,
                        "name": "My Company",
                        "is_main": true
                    },
                    {
                        "id": 745,
                        "name": "Another Company",
                        "is_main": false
                    }
                ]
            }
        },
        {
            "id": 2,
            "name": "Jane Doe",
            "companies": {
                "data": [
                    {
                        "id": 999,
                        "name": "Some Company",
                        "is_main": true
                    }
                ]
            }
        }
    ]
}

添加数据透视表属性的最佳方法是什么？如果设置了属性,则在公司变换器上添加is_main似乎不太干净.

对于第一个例子,我考虑使用参数？include = company_relationship：company_id(1),例如：

public function includeCompanyRelationship(Contact $contact, ParamBag $params) {
    // .. retrieve the pivot table data here
    $is_main = $company->is_main;

    // but Now I would need another transformer, when what I actually want is to push the value on the main array (same level)

    return $this->item(??, ??);
}

我理解如何检索数据透视数据(相关：Laravel 5.1 – pivot table between three tables, better option?),但不知道如何在https://github.com/thephpleague/fractal Transformer逻辑中添加它.

我已经有了一个ContactTransformer和CompanyTransformer,但是如果我将is_main添加到CompanyTransformer,我所做的所有调用(与联系人相关或不相关)也会期望该属性.

解决方法:

如果我正确地读了你,你可以利用一个CompanyTransformer来处理你是否希望设置is_main属性,但只有将$contact参数传递给它的构造函数时才会这样做：

class CompanyTransformer extends TransformerAbstract
{
    public function __construct(Contact $contact = null)
    {
        $this->contact = $contact;
    }

    public function transform(Company $company)
    {
        $output = [
            'id' => $company->id,
            'name' => $company->name,
        ];

        if($this->contact) {
            // This step may not be necessary, but I don't think the pivot data 
            // will be available on the $company object passed in
            $company = $this->contacts->find($company->id);
            // You may have to cast this to boolean if that is important
            $output['is_main'] = $company->pivot->is_main;
        }

        return $output;
    }
}

然后在includeCompanyRelationship中,只需使用参数传入新的CompanyTransformer：

public function includeCompanyRelationship(Contact $contact) 
{
    $companies = $contact->companies;

    return $this->collection($companies, new CompanyTransformer($contact));
}

无论您是直接呼叫公司端点,还是在嵌入公司关系数据时调用联系人的端点,这都应该有效.