Laravel Eloquent API 资源在没有数据时返回空数组

Question

我正在使用 etrepat baum laravel 模块来存储和生成层次结构。还使用 eloquent api 资源自定义返回的 json 数据。

如果没有 children 可用，则返回当前为空 children。是否有可能只有 children 可用？

当前结果

[{
    "id": "1",
    "text": "Vegetables",
    "children": [{
        "id": "2",
        "text": "Onion",
        "children": []
    }, {
        "id": "3",
        "text": "Tomato",
        "children": []
    }, {
        "id": "4",
        "text": "Chilli",
        "children": []
    }, {
        "id": "5",
        "text": "Potato",
        "children": []
    }]
}, {
    "id": "6",
    "text": "Fruits",
    "children": [{
        "id": "7",
        "text": "Apple",
        "children": [{
            "id": "12",
            "text": "Red Apple",
            "children": []
        }, {
            "id": "13",
            "text": "Green Apple",
            "children": []
        }]
    }, {
        "id": "8",
        "text": "Banana",
        "children": [{
            "id": "14",
            "text": "Red Banana",
            "children": []
        }, {
            "id": "15",
            "text": "Yellow Banana",
            "children": []
        }]
    }, {
        "id": "9",
        "text": "Orange",
        "children": []
    }, {
        "id": "10",
        "text": "Papaya",
        "children": []
    }, {
        "id": "11",
        "text": "Guava",
        "children": []
    }]
}]

预期结果

[{
    "id": "1",
    "text": "Vegetables",
    "children": [{
        "id": "2",
        "text": "Onion"
    }, {
        "id": "3",
        "text": "Tomato"
    }, {
        "id": "4",
        "text": "Chilli"
    }, {
        "id": "5",
        "text": "Potato"
    }]
}, {
    "id": "6",
    "text": "Fruits",
    "children": [{
        "id": "7",
        "text": "Apple",
        "children": [{
            "id": "12",
            "text": "Red Apple"
        }, {
            "id": "13",
            "text": "Green Apple"
        }]
    }, {
        "id": "8",
        "text": "Banana",
        "children": [{
            "id": "14",
            "text": "Red Banana"
        }, {
            "id": "15",
            "text": "Yellow Banana"
        }]
    }, {
        "id": "9",
        "text": "Orange"
    }, {
        "id": "10",
        "text": "Papaya"
    }, {
        "id": "11",
        "text": "Guava"
    }]
}]

CategoryResource.php

public function toArray($request) {
    return [
        'id' => (string) $this->id,
        'text' => (string) $this->name,
        'children' => CategoryResource::collection($this->children)
    ];
}

CategoryController.php

public function index()
{
        CategoryResource::withoutWrapping();
        $categories = Category::all()->toHierarchy()->values();
        return new CategoryResourceCollection($categories);
}

Answer 1

您可以在将其添加到数组之前进行检查，如果它为空，则不要将其添加到返回的数组中：

public function toArray($request) {
    $result =  [
            'id' => (string) $this->id,
            'text' => (string) $this->name
        ];

    $child = CategoryResource::collection($this->children);
    if (!$child->isEmpty()) {
       $result['children'] = $child;
    }

    return $result;
}

Answer 2

在 Laravel 5.7 中，您可以使用：

public function toArray($request) {
    return [
        'id' => (string) $this->id,
        'text' => (string) $this->name,
        'children' => CategoryResource::collection($this->whenLoaded('children'))
    ];
}

Answer 3

Laravel 5.7

的正确答案

public function toArray($request) {
    return [
        'id' => (string) $this->id,
        'text' => (string) $this->name,
        'children' => CategoryResource::collection($this->when(!$this->children->isEmpty()))
    ];
}

在这个例子中，如果 children 为空，children 键将在发送到客户端之前从资源响应中完全删除。

Answer 4

如果您还需要它与 Conditional Relationships 一起正常工作（即不触发每个关系的加载只是为了检查它是否为空），这是我能找到的最好方法（部分基于另一个在这里回答，加上一些试验和错误）

public function toArray($request)
{
    $children = $this->whenLoaded('children');
    return [
        'id' => $this->id,
        'text' => $this->text,
        'children' => $this->when(method_exists($children, 'isEmpty') && !$children->isEmpty(), CategoryResource::collection($children))
    ];
}

Laravel Eloquent API 资源在没有数据时返回空数组

Laravel Eloquent API resource is returning empty array when no data

eloquent

laravel-5.5