[Custom Module] Save temporary file

[Elby]

Hello!

 

I am just trying to develop my first simple module to understand Prestashop better.

 

What I am trying now is to create a QR-Code PNG which should be saved to some temporary folder for download.

 

My problem now is that my PNG file is created but not saved into any specified folder I tried.

I changed already folder permissions to 777 but that didnt help.

Tried with very basic PHP file manipulation fopen/fwrite/fclose but still no success.

 

Can someone please explain me the general procedure of dynamically open, change and save files within Prestashop modules?

 

Any help is truly appreciated!

Thanks,

Elby