Reusing of single library component in your project with Git `read-tree`

on-git-read-tree-and-dependencies.md

Here is a quick tip on pulling dependencies in your project using git read-tree command.

The Problem

How to use a single component from some library (eg. Form from Symfony), but not the whole library (tried the git submodule ?).

1. Init project:

   Create a new project and init Git:

   $ mkdir newproject
   $ cd newproject
   $ git init
   

2. Setup remote:

   You need to setup a remote (right now don't know how to skip the step) otherwise you would get a fatal: Not a valid object name error.

   $ git remote add -f symfony git@github.com:symfony/symfony.git
   

3. Import only the subdirecory subtree:

   $ git read-tree --prefix=src/Symfony/Component/Form/ -u symfony/master:src/Symfony/Component/Form
   

4. Pull in new changes:

   Pulling in changes might be as easy as repeating same steps over and over again but a better workflow should be proposed.

Any thoughts on pull/push are appreciated.

@martin_adamko