WebAPI Error: Class \"\\Vendor\\Module\\...\\FooBar[]\" does not exist

[NuktukDev]

Summary

I am trying to use the REST Web API to return a collection of a certain interface.

The docs specifically say:

Any parameters or return values of type array can be denoted by following any of the previous types by an empty set of square brackets []

And provide the example:

A return which is an array of objects of type \Magento\Customer\Api\Data\CustomerInterface:
@return \Magento\Customer\Api\Data\CustomerInterface[]

https://developer.adobe.com/commerce/php/development/components/web-api/services/#service-interface-requirements

Vendor\Module\Api\FooRepositoryInterface:

namespace Vendor\Module\Api;

interface FooRepositoryInterface
{
    /**
     * @param string $foo
     * @param string $bar
     * @return \Vendor\Module\Api\Data\FooInterface[]
     * @throws \Magento\Framework\Exception\NoSuchEntityException
     */
    public function getStatus($foo, $bar);
}

Vendor\Module\Api\Data\FooInterface:

<?php
namespace Vendor\Module\Api\Data;

use Magento\Framework\Exception\LocalizedException;

interface FooInterface {

    /**
     * @return ?int
     * @throws LocalizedException
     */
    public function getId();
    
    //...........
}

Vendor\Module\Model\FooRepository:

<?php
namespace Vendor\Module\Model\Api;

use Vendor\Module\Api\FooRepositoryInterface;

use Magento\Framework\Exception\NoSuchEntityException;

class FooRepository implements FooRepositoryInterface
{
  // ..........................
  /**
     * @inheritdoc
     */
    public function getStatus($foo, $bar)
    {
        return $this->FooCollectionFactory->create()
            ->addFieldToFilter('foo', ['eq' => $foo])
            ->addFieldToFilter('bar', ['eq' => $bar]);
     }
     // ............
}

When calling the API it gives me the error:

	"message": "Class \"\\Vendor\\Module\\Api\\Data\\FooInterface[]\" does not exist",
	"code": -1,
	"trace": "#0 \/var\/www\/html\/vendor\/magento\/framework\/Reflection\/MethodsMap.php(166): ReflectionClass->__construct('\\\Vendor\\\\...')\n#1 \/var\/www\/html\/vendor\/magento\/framework\/Reflection\/MethodsMap.php(115): Magento\\Framework\\Reflection\\MethodsMap->getMethodMapViaReflection('\\\\Vendor\\\\...')\n#2 \/var\/www\/html\/vendor\/magento\/framework\/Reflection\/DataObjectProcessor.php(92): Magento\\Framework\\Reflection\\MethodsMap->getMethodsMap('\\\\Vendor\\\\...')\n#3 \/var\/www\/html\/vendor\/magento\/framework\/Webapi\/ServiceOutputProcessor.php(126): Magento\\Framework\\Reflection\\DataObjectProcessor->buildOutputDataArray(Object(Vendor\\Module\\Model\\ResourceModel\\Foo\\Collection\\Interceptor), '\\\\Vendor\\\\...')

Examples

It seems that when it calls ReflectionClass() it puts the [] brackets in, I think it's supposed to be stripped first.

Proposed solution

No response

Release note

No response

Triage and priority

• Severity: S0 - Affects critical data or functionality and leaves users without workaround.
• Severity: S1 - Affects critical data or functionality and forces users to employ a workaround.
• Severity: S2 - Affects non-critical data or functionality and forces users to employ a workaround.
• Severity: S3 - Affects non-critical data or functionality and does not force users to employ a workaround.
• Severity: S4 - Affects aesthetics, professional look and feel, “quality” or “usability”.

[m2-assistant]

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[NuktukDev]

Just want to comment and say that I added ->getItems() to the end of the collection and it works now. Not sure if this should still be considered an issue, I'll let staff decide.

[m2-assistant]

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