TYPO3 Composer mode PSR-4 not loading classes

Question

I have an extension located under ext/my_ext. My viewhelper is located under /ext/my_agarar_template/Classes/ViewHelpers/TestViewHelper.php.

when I try to call my viewhelper, my template says that my class doesn't exist.

My template looks like this:

{namespace p=ext\my_ext\ViewHelpers}
h1>ViewHelper-Test</h1>
<p><p:HelloWorld /></p>

Here is my error message:

Oops, an error occurred! Fluid parse error in template Standard_action_my_ext_slide_db2750e6ca45c0832d4fc312cf0618afbe9329d0, line 11 at character 5. Error: The ViewHelper "" could not be resolved. Based on your spelling, the system would load the class "ext\my_ext\ViewHelpers\TestViewHelper", however this class does not exist. (error code 1407060572). Template source chunk: More information regarding this error might be available online.

I load it via Composer and my PSR-4 looks like this:

"autoload": {
    "psr-4": {
      "myext\\MyExt\\": "web/typo3conf/ext/my_ext/Classes"
    }
}

I don't know why my classes aren't loading.

Hope someone can help me,

thanks in advance.

You should post your template where you are trying to use the viewhelper. Also you should post the exact error message you see. — Mathias Brodala
Your psr-4 declaration is wrong, this should be "myext\\MyExt\\": "Classes". After the change you have to run composer dump-autoload — Simon Gilli

Sybille Peters Sybille Peters · Accepted Answer · 2019-10-08T05:54:57

As mentioned, your autoload section looks weird in composer.json. However, your autoloading seems to be working, otherwise you would probably not get this far, I guess.

I would check the following:

check composer.json autoload section
check spelling of files and class names: The ViewHelper class should be in Classes/ViewHelpers and should be the same filename + classname HelloWorldViewHelper.php and class HelloWorldViewHelper (this looks ok from your sample code)
is namespace correct in ViewHelper class?
just to be sure: Is your template code valid XML? (there is a '<' missing in h1)
why is the class called TestViewHelper but the name is HelloWorld? Should be HelloWorldViewHelper and <p:helloWorld>. Watch for upper / lower case.
clear entire cache (again) and dump autoload (again) composer dump-autoload
you can check the file vendor/composer/autoload_psr4.php to see if the mapping namespace to filename is correct.

In general, I would stay away from extension keys with underscores ('_'). This is also recommended in the documentation. The thing is: The spelling, using correct upper and lowercase, vendor name or not etc. can be challenging enough. Using underscore in extension keys makes this even more difficult. Not a problem if you know the rules or know where to look but poses unnecessary difficulties for beginners.

Tip: Look in bootstrap_package. It has an underscore in the name and contains ViewHelpers.

TYPO3 Composer mode PSR-4 not loading classes

1 Answers