What is Composer and why should every PHP developer use it

The Stone Age PHP developer will do the following: He will download a copy of the framework, and then create a folder in which he places the additional libraries he needs and then try to understand how they work to link them together. This method may pay off, and it may allow you to develop your project "without any problems," but what happens, for example, if an update is launched to any of the libraries that you depend on? Will you reload it again and replace the old version with the new one? Could you do that if you use more than one interdependent library? Not sure about that. But what is the alternative? If you have ever used other programming languages ​​such as javascript with node.js or ruby, then you have dealt with what is called a package manager, where npm is used with node, for example, to install packages and plugins for node. The composer position in PHP can be said to be the npm placement of node.js, as composer allows you to download the libraries you need in your project and keep them up-to-date without having to manually download and move them. Despite all of this, the official composer site indicates that it is not possible to call it a package manager by virtue of the fact that it does not generally install these packages on the global system, but rather the packages within each project are managed locally, and that is why it is called the Dependency Manager.

Installing composer

Let's go in theory and let's install composer and look at how to use it. Although it can be installed locally within every project, it is generally preferred to have it installed on the system. On Linux / Unix systems, the following two commands are sufficient to install composer:

$ curl -sS https://getcomposer.org/installer | php
$ mv composer.phar /usr/local/bin/composer

You may need to add sudo before the second command if you need administrator privileges to execute the command.

On Windows systems, it is sufficient to download and install its official application.

You can check if composer is installed correctly on the system by executing the composer command at the command line which should display its help.

Use Composer

Now that we have installed composer, we will need to create a composer.json file through which we inform composer of the packages that we want to attach and rely on in our new project, and this file can contain other data that we will need in building the project.

In its simplest form, the composer.json file looks like this:

{
    "require": {
        "monolog/monolog": "1.0.*"
    }
}

For this example we are relying on version 1.0. * Of the monolog library. Of course, it is possible to rely on more than one library in our current project, as it is sufficient to add a new line for each library between the two require incubators, and each line consists of the name of the library (which usually contains the name of the entity producing it followed by its name, and the same name is usually repeated twice) Add to the version number we want.

These libraries and the mechanisms for adding them to your search project can be found at https://packagist.org/.

Now that we have identified the desired libraries, it is sufficient for us to execute the command