Custom Rest API for custom table not wroking

Question

My webapi.xml is below.

<?xml version="1.0"?>
<routes xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Webapi:etc/webapi.xsd">
     <route url="/V1/garage/insert/" method="POST">
        <service class="Garage\Motogaadi\Api\GarageInsert" method="insert"/>
        <resources>
           <resource ref="anonymous"/>
        </resources>
    </route>
</routes>

Also my di.xml is below

<?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="Garage\Motogaadi\Api\GarageInsert" type="Garage\Motogaadi\Model\GarageAdd" />
</config>

My interface is below.

<?php
namespace Garage\Motogaadi\Api;

interface GarageInsert
{

    /**
     * Returns greeting message to user
     *
     * @api
     * @param string $data Users name.
     * @return string Greeting message with users name.
     */

    public function  insert($data);
}

My model is below

<?php
namespace Garage\Motogaadi\Model;
use Garage\Motogaadi\Api\GarageInsert;

class GarageAdd implements GarageInsert
{

    /**
     * Returns greeting message to user
     *
     * @api
     * @param string $data Users name.
     * @return string Greeting message with users name.
     */

    public function insert($data)
    {   


        //Customize the code as per your requirement.
        $cid = $data['id'];
        $gid = $data['gid'];
        $objectManager = \Magento\Framework\App\ObjectManager::getInstance(); // Instance of object manager
        $resource = $objectManager->get('Magento\Framework\App\ResourceConnection');
        $connection = $resource->getConnection();
        $tableName = $resource->getTableName('garage_customer_ids');
        $sql = "Insert Into " . $tableName . " ( customer_id, garage_data_id) Values ('$cid','$gid')";     
        $connection->query($sql);       
        return 'successfully saved';

    }
}

I get the below error when I post the data.

"message": "The \"array\" value's type is invalid. The \"string\" type was expected. Verify and try again.",

Answer 1

You just need to change parameter type in your interface. Set $data type "array" from "string" :

<?php
namespace Garage\Motogaadi\Api;

interface GarageInsert
{

    /**
     * Returns greeting message to user
     *
     * @api
     * @param array $data
     * @return string Greeting message with users name.
     */

    public function  insert($data);
}

You can add this one also : * @param string[] $data

Answer 2

Please remove generated directory and run below command once to fix type error occurred when creating object error

php bin/magento setup:upgrade
php bin/magento cache:clean
php bin/magento cache:flush

Hope this will help you!