I've installed Swipestripe module. and added swipestripe-gallery module for product images. when I did dev/bulid?flush=1 it shows error Class 'Gallery_PageExtension' does not exists I have seen gallery.yml file in swipestripe-gallery/_config folder, which has
Product:
extensions:
- 'Gallery_PageExtension'
but this class is not there in Product.php file in swipestripe-gallery/code folder. After commenting above code I did dev/build?flush=1 & there was no error. But in product page the Gallery tab is not added. Please Help.
You didn't install using composer? Your fault ;) It installs all requirements for you and you can code happy.
See https://github.com/swipestripe/silverstripe-swipestripe-gallery#requirements, you'll need to install https://github.com/frankmullenger/silverstripe-gallery for getting this gallery extension in your codebase.
I strongly encourage you to install ALL modules with composer. It may be a bit hard in the beginning, but in some days your life will be much more comfortable! A good introduction can be found in the ss docs.