I have created an extension with plugins in a vendor namespace. Everything works fine so far. All the classes start with a namespace declaration namespace \VENDOR\ExtensionName\... and typo3 autoloads them just fine.
However, the problem starts when I add a ViewHelper. I put this in the \VENDOR\ExtensionName\ViewHelpers namespace. I added the namespace in my Fluid template like so: {namespace ns=VENDOR\ExtensionName\ViewHelpers}. When I call it in the template with <ns:myViewHelper />, I just get an 'Oops ...' error message:
Could not analyse class:VENDOR\ExtensionName\ViewHelpers\MyViewHelperViewHelper maybe not loaded or no autoloader?
The same happens, when I put the ViewHelper in a \TYPO3\... namespace.
How do I correctly implement a ViewHelper in an extension with a vendor namespace?
The namespace declaration must not have a leading backslash.
Instead having \Vendor\ExtensionName\ViewHelpers; it has to be Vendor\ExtensionName\ViewHelpers;