PHP Composer - How to work with multiple vendors?

Question

The project I'm working on requires using the PHP SDK's from multiple 3rd parties. Two of these are Amazon Web Services and the Google API Client (for Google+), and both of them use Composer to manage their files / dependencies. I'm not sure how to best set it up code / structure wise, though, because I don't need both AWS and Google loaded together. I might need AWS in one area and Google in another, so I don't want to just autoload everything every time and have the additional overhead from libraries I don't need right then. Right now I have the structure set up like this:

• awscode.php
• googlecode.php
• libs
  
  • composer.json
  • composer.lock
  • vendor
    • autoload.php
    • aws
    • google

So, everything Composer related is in a shared composer.json file, and all vendor files in the single vendor directory. But, I can't seem to find a way to just load up say AWS. It wants me to use the autoload.php from what I can tell, which seems to want to load up everything.

Do I need to set it up more like this if I want control over each library?

• awscode.php
• googlecode.php
• libs
  • aws
    • composer.json
    • composer.lock
    • vendor
      • autoload.php
      • aws
  • google
    • composer.json
    • composer.lock
    • vendor
      • autoload.php
      • google

I'm obviously new to Composer and how to best utilize it, and want to make sure that I am setting it up the best way for both my situation, and for future management.

Answer 1

When using Composer, it only loads the classes when they are actually called in your code. To my knowledge this uses the PHP spl_autoload_register.

So in answer to your question, there won't be a significant extra overhead (if any).

Answer 2

Autoloading means that the file which defines a class gets read when you first use that class.

You should include all your project dependencies in one composer.json, they won't be loaded in files you don't use them in.