Laravel Eloquent API resource is returning empty array when no data

Question

I am using etrepat baum laravel module to store and generate hierarchy. Also using eloquent api resource to customize the json data returned.

Currently empty children are returned if no children available. Is it possible to have children only if available?

Current Result

[{
    "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": []
    }]
}]

Expected Result

[{
    "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

You can check before adding it to the array and if it's empty don't add it to the returned array :

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

In Laravel 5.7, you could use:

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