Make frontend/backend fully optional when installing spree gem

[damianlegawiec]

This makes Spree a more modular and headless API-first platform.

1. spree gem does not include spree_frontend nor spree_backend
2. spree_frontend and spree_backend don't require specific spree_core / spree_api version, so older frontend can work with newer spree_core (scenario: developer updated spree core, spree API but does not update spree frontend at the same time)

[viezly]

Full changes overview:

Show details on Viezly ➡️

[MatthewKennedy]

Could add the frontend install command to the docs
bundle exec rails g spree:frontend:install

[MatthewKennedy]

Hi @damianlegawiec

I've just fired this up locally

• Installed spree_core only - Worked Perfectly
• Added spree_frontend gem (gem 'spree_frontend', path: '../spree/frontend') and run the install command - Worked Perfectly
• Added backend gem (gem 'spree_backend', path: '../spree/backend') - Worked Perfectly

Notes: Had to use local path to the gems, as I think the frontend and backend stand alone gems are not published, or if published possibly need updating when the time is right.

Documentation of the install commands is about the only thing I had to find out by a little digging during the install process:
bundle exec rails g spree:frontend:install
bundle exec rails g spree:backend:install

Other than that, very nice!

[damianlegawiec]

Hi @damianlegawiec

I've just fired this up locally

• Installed spree_core only - Worked Perfectly
• Added spree_frontend gem (gem 'spree_frontend', path: '../spree/frontend') and run the install command - Worked Perfectly
• Added backend gem (gem 'spree_backend', path: '../spree/backend') - Worked Perfectly

Notes: Had to use local path to the gems, as I think the frontend and backend stand alone gems are not published, or if published possibly need updating when the time is right.

Documentation of the install commands is about the only thing I had to find out by a little digging during the install process:
bundle exec rails g spree:frontend:install
bundle exec rails g spree:backend:install

Other than that, very nice!

Awesome! Yes, we need to update the docs after the first public 4.3 release and yes frontend/backend gems need to be updated on rubygems, actually you can run the generators/installers from the main one by:

rails g spree:install --install_storefront=true --install_admin=true