What goes in the upload configuration (path) to save an image in the fileadmin user_upload folder in typo3 10?

Question

I named my image file upload as "myImage" an want to ask what goes in in the path in the code below to upload an image in my user_upload folder in a typo3 10 backend extension. The extension which I want to create as: in the upload example extension

{namespace h=Vendor\ExtensionName\ViewHelpers}

<h:form.upload property="myImage">
    <f:if condition="{resource}">
        <f:image image="{resource}" alt="" width="50"/>
    </f:if>
</h:form.upload>

protected function setTypeConverterConfigurationForImageUpload($argumentName)
    {
        \TYPO3\CMS\Core\Utility\GeneralUtility::makeInstance(\TYPO3\CMS\Extbase\Object\Container\Container::class)
            ->registerImplementation(
                \TYPO3\CMS\Extbase\Domain\Model\FileReference::class,
                \Vendor\ExtensionName\Domain\Model\FileReference::class
            );

        $uploadConfiguration = [
            UploadedFileReferenceConverter::CONFIGURATION_ALLOWED_FILE_EXTENSIONS => $GLOBALS['TYPO3_CONF_VARS']['GFX']['imagefile_ext'],
            UploadedFileReferenceConverter::CONFIGURATION_UPLOAD_FOLDER => '1:/fileadmin/myfolder/', // here is the point of my question
        ];
        /** @var PropertyMappingConfiguration $newExampleConfiguration */
        $newExampleConfiguration = $this->arguments[$argumentName]->getPropertyMappingConfiguration();
        $newExampleConfiguration->forProperty('myImage')
            ->setTypeConverterOptions(
                UploadedFileReferenceConverter::class,
                $uploadConfiguration
            );

    }

Answer 1

CONFIGURATION_UPLOAD_FOLDER is a combined identifier. Combined identifies have the syntax:

< storage uid >: < file identifier >

Normally, you have the default storage (fileadmin) with UID 1. The uploadfolder may be in this storage, so it has to be prefixed with "1:". After the storage UID, the path in this storage follows.

In your case of target folder /fileadmin/myfolder/ the first part will automatically be added by the defined storage. The path in this storage is myfolder.

So, you should set your CONFIGURATION_UPLOAD_FOLDER

1:/myfolder