How to Install Only One Package with Composer

You may want to install only one or two packages with composer to avoid resolving too many dependences and errors like

 Composer\DependencyResolver phar:///home/my_project/composer.phar/src/Composer/DependencyResolver/Solver.php:166

The first thing is to do a self update:

php composer.phar self-update

php -dmemory_limit=1024M composer.phar update codeplex/phpexcel

Installing two packages:

php -dmemory_limit=1024M composer.phar update symfony/monolog-bundle codeplex/phpexcel

Adding the option memrory limit will avoid some important out of memory errors

Installing a whole set of vendors or packages

If you have to update most of your packages or vendors, the best way to do it is:

- Validate that all vendors you want are listed in the composer.json file

- Make a backup of your vendors directory somewhere.

- Delete all the content in your vendor directory

Do a :

php composer.phar install

This way composer will install the best dependency version for every vendor in a clean space. Having to update existing vendor's directory may bring too many dependences conflicts to resolve.