Magento 2.4.6. Unable to output data to json

Question

I have a problem with the json output when sending a request to the API.

I receive data in this format:

"{\n    \"name\": \"John\",\n    \"age\": 30,\n    \"car\": null,\n   \"address\": {\n        \"street\": \"123 Main St\",\n        \"city\": \"Anytown\",\n        \"zip\": \"12345\"\n    }\n}"

I need the data in this format:

{
    "name": "John",
    "age": 30,
    "car": null,
    "address": {
        { "street": "123 Main St",
        "city": "Anytown",
        "zip": "12345"
    }
}

Am I correct in understanding that this is because I am using such an interface on my side?

namespace Dev\RestApi\Api;

interface TestInterface
{
    /**
    *
    * @return string
    */
    public function testMethod();
}

My Model:

namespace Dev\RestApi\Model;

use Dev\RestApi\Api\TestInterface;

class TestModel implements TestInterface
{
    public function testMethod()
    {

        $data = [
            'name' => 'John',
            'age' => 30,
            'car' => null,
            'some' => null,
            'address' => [
                'street' => '123 Main St',
                'city' => 'Anytown',
                'zip' => '12345'
            ]
        ];

        $jsonResponse = json_encode($data, JSON_PRETTY_PRINT);

        return $jsonResponse;
    }
}

Answer 1

If you want to return the result as a JSON object via a rest API call, you must use data objects with appropriate interfaces. Your method (testMethod()) should return, say, CustomerDataInterface, whereas CustomerDataInterface should have a getAddress method that returns AddressDataInterface. The Rest API has some limitations, and one of them is the inability to return simple arrays.

Example:

app/code/Dev/RestApi/Api/Data/AddressInterface.php

namespace Dev\RestApi\Api\Data;

interface AddressInterface
{
    /**
     * Get street.
     *
     * @return string|null
     */
    public function getStreet(): ?string;

    /**
     * Get city.
     *
     * @return string|null
     */
    public function getCity(): ?string;

    /**
     * Get zip code.
     *
     * @return string|null
     */
    public function getZip(): ?string;
}

app/code/Dev/RestApi/Model/Address.php

namespace Dev\RestApi\Model;

use Dev\RestApi\Api\Data\AddressInterface;

class Address implements AddressInterface
{
    /**
     * @var string|null
     */
    private $street;

    /**
     * @var string|null
     */
    private $city;

    /**
     * @var string|null
     */
    private $zip;

    /**
     * Set street.
     *
     * @param string|null $street
     * @return AddressInterface
     */
    public function setStreet(?string $street): AddressInterface
    {
        $this->street = $street;
        return $this;
    }

    /**
     * Set city.
     *
     * @param string|null $city
     * @return AddressInterface
     */
    public function setCity(?string $city): AddressInterface
    {
        $this->city = $city;
        return $this;
    }

    /**
     * Set zip code.
     *
     * @param string|null $zip
     * @return AddressInterface
     */
    public function setZip(?string $zip): AddressInterface
    {
        $this->zip = $zip;
        return $this;
    }

    /**
     * Get street.
     *
     * @return string|null
     */
    public function getStreet(): ?string
    {
        return $this->street;
    }

    /**
     * Get city.
     *
     * @return string|null
     */
    public function getCity(): ?string
    {
        return $this->city;
    }

    /**
     * Get zip code.
     *
     * @return string|null
     */
    public function getZip(): ?string
    {
        return $this->zip;
    }
}

app/code/Dev/RestApi/Api/Data/MainDataInterface.php

namespace Dev\RestApi\Api\Data;

interface MainDataInterface
{
    /**
     * Get name.
     *
     * @return string|null
     */
    public function getName(): ?string;

    /**
     * Get age.
     *
     * @return int|null
     */
    public function getAge(): ?int;

    /**
     * Get car.
     *
     * @return string|null
     */
    public function getCar(): ?string;

    /**
     * Get some.
     *
     * @return string|null
     */
    public function getSome(): ?string;

    /**
     * Get address.
     *
     * @return \Dev\RestApi\Api\Data\AddressInterface
     */
    public function getAddress(): AddressInterface;
}

app/code/Dev/RestApi/Model/MainData.php

namespace Dev\RestApi\Model;

use Dev\RestApi\Api\Data\MainDataInterface;
use Dev\RestApi\Api\Data\AddressInterface;

class MainData implements MainDataInterface
{
    /**
     * @var string|null
     */
    private $name;

    /**
     * @var int|null
     */
    private $age;

    /**
     * @var string|null
     */
    private $car;

    /**
     * @var string|null
     */
    private $some;

    /**
     * @var AddressInterface
     */
    private $address;

    public function __construct(AddressInterface $address)
    {
        $this->address = $address;
    }

    /**
     * Set name.
     *
     * @param string|null $name
     * @return MainDataInterface
     */
    public function setName(?string $name): MainDataInterface
    {
        $this->name = $name;
        return $this;
    }

    /**
     * Set age.
     *
     * @param int|null $age
     * @return MainDataInterface
     */
    public function setAge(?int $age): MainDataInterface
    {
        $this->age = $age;
        return $this;
    }

    /**
     * Set car.
     *
     * @param string|null $car
     * @return MainDataInterface
     */
    public function setCar(?string $car): MainDataInterface
    {
        $this->car = $car;
        return $this;
    }

    /**
     * Set some.
     *
     * @param string|null $some
     * @return MainDataInterface
     */
    public function setSome(?string $some): MainDataInterface
    {
        $this->some = $some;
        return $this;
    }

    /**
     * Get name.
     *
     * @return string|null
     */
    public function getName(): ?string
    {
        return $this->name;
    }

    /**
     * Get age.
     *
     * @return int|null
     */
    public function getAge(): ?int
    {
        return $this->age;
    }

    /**
     * Get car.
     *
     * @return string|null
     */
    public function getCar(): ?string
    {
        return $this->car;
    }

    /**
     * Get some.
     *
     * @return string|null
     */
    public function getSome(): ?string
    {
        return $this->some;
    }

    /**
     * Get address.
     *
     * @return \Dev\RestApi\Api\Data\AddressInterface
     */
    public function getAddress(): AddressInterface
    {
        return $this->address;
    }
}

Update preferences in the di.xml:

app/code/Dev/RestApi/etc/di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
    <preference for="Dev\RestApi\Api\Data\MainDataInterface" type="Dev\RestApi\Model\MainData" />
    <preference for="Dev\RestApi\Api\Data\AddressInterface" type="Dev\RestApi\Model\Address" />
</config>

Update your main interface and model:

app/code/Dev/RestApi/Api/TestInterface.php

namespace Dev\RestApi\Api;

use Dev\RestApi\Api\Data\MainDataInterface;

interface TestInterface
{
    /**
     * @return MainDataInterface
     */
    public function testMethod(): MainDataInterface;
}

app/code/Dev/RestApi/Model/TestModel.php

namespace Dev\RestApi\Model;

use Dev\RestApi\Api\TestInterface;
use Dev\RestApi\Api\Data\MainDataInterface;
use Dev\RestApi\Model\MainData; // Assuming you have MainData class

class TestModel implements TestInterface
{
    public function testMethod(): MainDataInterface
    {
        $mainData = new MainData();
        
        $mainData
            ->setName('John')
            ->setAge(30)
            ->setCar(null)
            ->setSome(null);

        $address = new Address();
        $address
            ->setStreet('123 Main St')
            ->setCity('Anytown')
            ->setZip('12345');

        $mainData->setAddress($address);

        return $mainData;
    }
}

PS: This is just a quickly generated sample code, you should update it to suit your needs and best practices!

Answer 2

If you want to get JSON foramt, you can use Magento\Framework\Controller\Result\JsonFactory

In TestModel, inject JsonFactory into the class and set the $data into JsonFactory. So that:

namespace Dev\RestApi\Model;

use Dev\RestApi\Api\TestInterface;
use Magento\Framework\Controller\Result\JsonFactory;

class TestModel implements TestInterface
{
    protected JsonFactory $jsonFactory;

    public function __construct(
        JsonFactory $jsonFactory
    ){
        $this->jsonFactory = $jsonFactory;
    }

    public function testMethod()
    {

        $data = [
            'name' => 'John',
            'age' => 30,
            'car' => null,
            'some' => null,
            'address' => [
                'street' => '123 Main St',
                'city' => 'Anytown',
                'zip' => '12345'
            ]
        ];

        $jsonResponse = $this->jsonFactory->create();
        $jsonResponse->setData($data);

        return $jsonResponse;
    }
}