Namespace causing PHP Fatal error: Uncaught Error: Class Not Found error

Question

I have three libraries installed via composer.

https://github.com/barbushin/php-imap
https://github.com/PHPMailer/PHPMailer
https://github.com/openai-php/client

and I have tried to use it in my index.php file like

<?php
    namespace PhpImap;
    use PHPMailer\PHPMailer\PHPMailer;
    use PHPMailer\PHPMailer\SMTP;
    use PHPMailer\PHPMailer\Exception;
    require 'vendor/autoload.php';
    .....
?>

Its giving me error on this line

$client = OpenAI::client($yourApiKey);

called

PHP Fatal error:  Uncaught Error: Class "PhpImap\OpenAI" not found in /home/myuser/mydomain.com/dashboard/crons/reply/reply.php:216

My composer.json is like below

{
    "config": {
        "allow-plugins": {
            "php-http/discovery": true
        }
    },
    "require": {
        "php-imap/php-imap": "^5.0",
        "phpmailer/phpmailer": "^6.8",
        "openai-php/client": "^0.6.4",
        "symfony/http-client": "^6.3",
        "nyholm/psr7": "^1.8"
    }
}

If I remove Namespace PhpImap from 2nd line, its work but its required for my imap function. I think that namespace conflict with OpenAi library. I do not getting idea to resolve the issue. Let me know if someone can help me for solve the issue. Thanks!

score 1 · Answer 1 · answered Jul 29 '23 at 07:52

1

The OpenAI class is not namespaced, which means that you need to prefix it with a \ when you use it:

$client = \OpenAI::client($yourApiKey);

answered Jul 29 '23 at 07:52

Olivier

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Thanks, It have solved the issue. Thanks! – Manisha Jul 29 '23 at 07:53

score 1 · Accepted Answer · answered Jul 29 '23 at 08:28

You might want to read through the explanation of namespaces in the PHP manual to understand the key concepts.

One way to think about it is that the full name of a class can have parts separated by \, and all the namespace machinery is just ways of referring to the class by shorter names. Simplifying a bit, there are two ways that happens:

The namespace keyword specifies a default prefix for all classes in a particular file
The use keyword specifies particular exceptions to that rule, where a short name refers to something with a different prefix

Importantly, these two rules take priority over looking for a class with no namespace prefix at all. To say you don't want any prefix to be added, you have to make a name "fully qualified" with a leading \.

In your case, the full name of the class you want to use is OpenAI with no prefix, but you've told PHP to add the prefix PhpImap by default, so it's looking for PhpImap\OpenAI. You need to either:

Specify it as \OpenAI
Add a use statement at the top of the file, use OpenAI; to tell the compiler that you want OpenAI on its own to refer to the class throughout the file

Namespace causing PHP Fatal error: Uncaught Error: Class Not Found error

2 Answers2