Create Custom Rest Api in Magento2 and solution for "InvalidArgumentException" error

Question

I started on Magento2 Custom rest API module creation for that i follow the below post

API Module for Magneto2

url:- http://localhost/magento2a/rest/V1/calculator/add/1/2

app/code/AlanKent/CalculatorWebService/etc/module.xml

<?xml version="1.0"?>
<!--
/**
 * @copyright Copyright (c) 2015 X.commerce, Inc. (http://www.magentocommerce.com)
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/Module/etc/module.xsd">
 <module name="AlanKent_CalculatorWebService" setup_version="2.0.0"/>
</config>

app/code/AlanKent/CalculatorWebService/etc/di.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright 2015 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../lib/internal/Magento/Framework/ObjectManager/etc/config.xsd">
 <preference for="AlanKent\CalculatorWebService\Api\CalculatorInterface"
 type="AlanKent\CalculatorWebService\Model\Calculator" />
</config>

app/code/AlanKent/CalculatorWebService/etc/webapi.xml

<?xml version="1.0"?>
<!--
/**
 * Copyright 2015 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
-->
<routes xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../../../app/code/Magento/Webapi/etc/webapi.xsd">
 <!-- Example: curl http://127.0.0.1/index.php/rest/V1/calculator/add/1/2 -->
 <route url="/V1/calculator/add/:num1/:num2" method="GET">
 <service class="AlanKent\CalculatorWebService\Api\CalculatorInterface" method="add"/>
 <resources>
 <resource ref="anonymous"/>
 </resources>
 </route>
</routes>

app/code/AlanKent/CalculatorWebService/Api/CalculatorInterface.php

<?php
/**
 * Copyright 2015 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace AlanKent\CalculatorWebService\Api;
use AlanKent\CalculatorWebService\Api\Data\PointInterface;
/**
 * Defines the service contract for some simple maths functions. The purpose is
 * to demonstrate the definition of a simple web service, not that these
 * functions are really useful in practice. The function prototypes were therefore
 * selected to demonstrate different parameter and return values, not as a good
 * calculator design.
 */
interface CalculatorInterface
{
 /**
 * Return the sum of the two numbers.
 *
 * @return int The sum of the numbers.
 */
 public function add($num1, $num2);
}

app/code/AlanKent/CalculatorWebService/Model/Calculator.php

<?php
/**
 * Copyright 2015 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace AlanKent\CalculatorWebService\Model;
use AlanKent\CalculatorWebService\Api\CalculatorInterface;
/**
 * Defines the implementaiton class of the calculator service contract.
 */
class Calculator implements CalculatorInterface
{
 /**
 * Return the sum of the two numbers.
 *
 * @api
 * @param int $num1 Left hand operand.
 * @param int $num2 Right hand operand.
 * @return int The sum of the two values.
 */
 public function add($num1, $num2) {
 return $num1 + $num2;
 }
}

it work fine for me

Guys if you get error

 [2015年10月14日 09:24:54] main.CRITICAL: exception 'InvalidArgumentException' with message 'Report ID: webapi-561e0346e13a1; Message: Each getter must have description with @return annotation. See Magento\Catalog\Api\ProductTypeListInterface::getTests()' in D:\xampp\htdocs\magento2a\lib\internal\Magento\Framework\Webapi\ErrorProcessor.php:194

then make sure in Interface file where you declare the function above that there should be @return in comments else it will through error

that is getTests its my new method aove that i have comment with @return if you missed the it will through the error

<?php
/**
 * Product type provider
 *
 * Copyright © 2015 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Magento\Catalog\Api;
/**
 * @api
 */
interface ProductTypeListInterface
{
 /**
 * Retrieve available product types
 *
 * @return \Magento\Catalog\Api\Data\ProductTypeInterface[]
 */
 public function getProductTypes();
 **/**
 * Retrieve available product types
 *
 * @return
 */**
 public function getTests();
}

it look wired but its works above is the solution for Error

main.CRITICAL: exception 'InvalidArgumentException' with message 'Report ID: webapi-561e0346e13a1; Message: Each getter must have description with @return annotation. 

Note:- once module is pasted dont forget to run upgrade command that is D:\xampp\php>php D:\xampp\htdocs\magento2a\bin\magento setup:upgrade

(in local system i have php in D drive so change as per your system)

• KAndy: Why do you have comment like ` **/**`?

Answer 1

The interface must have proper dock blocks with the existing types. But your code doesn't have a return type. For example:

<?php 
/**
 * Product type provider
 *
 * Copyright © 2015 Magento. All rights reserved.
 * See COPYING.txt for license details.
 */
namespace Magento\Catalog\Api;
/**
 * @api
 */
interface ProductTypeListInterface
{
 /**
 * Retrieve available product types
 *
 * @return \Magento\Catalog\Api\Data\ProductTypeInterface[]
 */
 public function getProductTypes();
 /**
 * Retrieve available tests
 *
 * @return \Vendor\Module\Api\Data\TestInterface[]
 */
 public function getTests();
}

• Pradeep Kumar: :- i just gave below code it works code<?php namespace AlanKent\CalculatorWebService\Api; use AlanKent\CalculatorWebService\Api\Data\PointInterface; interface CalculatorInterface { /** * Return the sum of the two numbers. * * @api * @param int $num1 * @param int $num2 * @return */ public function add($num1, $num2); } code

Answer 2

@Kandy

i used below code it working fine for me important is dont ignore the comments which is consider as param

<?php
namespace AlanKent\CalculatorWebService\Api;
use AlanKent\CalculatorWebService\Api\Data\PointInterface;
interface CalculatorInterface
{
 /**
 * Return the sum of the two numbers.
 *
 * @api
 * @param int $num1
 * @param int $num2
 * @return
 */
 public function add($num1, $num2);
}