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Environment Variables with PHP

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Setting up the Project and Package

5:06 with Alena Holligan

Although environment variable are not code specific, we can still benefit from using a package to work with these variable. This video will demonstrate the application we'll be working with and step through the basics of working with the phpdotenv package.

Autoloading Classes in PHP

Many developers writing object-oriented applications create one PHP source file per class definition. One of the biggest annoyances is having to write a long list of needed includes at the beginning of each script (one for each class).

Since PHP 5, this is no longer necessary. The spl_autoload_register() function registers any number of autoloaders, enabling for classes and interfaces to be automatically loaded if they are currently not defined. By registering autoloaders, PHP is given a last chance to load the class or interface before it fails with an error.

Composer has accepted the standard put out by the PHP-FIG (Framework Interop Group) of how autoloaders should work in PSR-4: Autoloading

Setting Environment Variables

There are many different ways to set/access environment variables.

  1. Through code
    • Typically with a .env file using a package. We used phpdotenv in this video
    • Set directly with putenv()
    • Also using a .htaccess file (example) 
      
//make sure you AllowOverrides
//have enabled mod_en
SetEnv SPECIAL_PATH /foo/bin
  2. On the system*
    • The hosting company's dashboard such as AWS
    • System wide /etc/environment
    • Apache virtual host (example of file located somewhere similar to /etc/apache2/sites-available*) 
      
<VirtualHost host1>
SetEnv SPECIAL_PATH /foo/bin
...
</VirtualHost>

* try a google search for your particular setup

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    For this course, I've gone ahead and 0:00
    prepared a simple application called developers say the darnedest things. 0:01
    This application has two pages. 0:06
    On each refresh, 0:09
    the homepage randomly displays something a developer commonly says. 0:10
    The contact page has a form to email a comment or a suggestion. 0:15
    It also includes a Google reCAPTCHA to reduce spam. 0:21
    We're not going to change the functionality of this site at all. 0:30
    Instead, we're going to use our knowledge of environment variables to 0:34
    upgrade the application. 0:38
    We're going to use environment variables to move the credentials for SMTP and 0:40
    reCAPTCHA, and to change the data source for the quotes. 0:45
    First, we need to be able to set environment variables. 0:49
    There are many different ways to do this, but 0:53
    they all fall into two main camps, set them on the server, or set them with code. 0:55
    If you recall, one of the benefits of environment variables 1:01
    is that they aren't stored in our code. 1:04
    So why would we want to set them with code? 1:06
    On a production server, you probably wouldn't, but for 1:10
    development environment, there are a number of advantages. 1:13
    There are packages that provide additional functionality 1:16
    such as specifying required variables. 1:21
    They can be used in conjunction with environment variables 1:24
    managed on the server. 1:27
    You don't need to know how to manage a server. 1:29
    You can set different variables for 1:32
    different projects even if they're using the same development environment. 1:34
    You can store these variables in a separate file 1:38
    that doesn't get added to a version control system. 1:41
    We're going to use a package called php.env. 1:45
    But I'll include additional resources for 1:49
    server management in the notes associated with this video. 1:51
    Let's check out our package. 1:55
    The first thing we read in this package is that it loads environment variables 1:58
    from a .env file. 2:02
    This script was modified from the Ruby version, 2:05
    and there is also a JavaScript version and more. 2:07
    These .env files are the same across languages and 2:10
    can also be used in the command line. 2:13
    Let's install this package with Composer. 2:16
    Open our console. 2:24
    And paste. 2:28
    The first thing we need to do is make sure that the .env file that we're going to use 2:30
    is added to our gitignore file so that it's not checked into version control. 2:35
    Since we can't edit a file that starts with a dot in the workspace editor, 2:41
    we're going to use the console and type, nano .gitignore. 2:46
    We're going to add a line for .env. 2:54
    Then follow the prompts, Ctrl+O to output, Enter to accept, and Ctrl+X will exit. 2:58
    Next, we need to add the .env file itself. 3:06
    Once again, we'll use the console. 3:10
    We type nano inc/.env to put it in the ink folder. 3:12
    Let's start by just adding a sample variable. 3:21
    Remember to use all uppercase letters for the variable name, SECRET= "Treehouse". 3:24
    This isn't a php file, it's a config file. 3:32
    So we don't end the line with a semicolon. 3:35
    Instead, each variable is on it's own line. 3:38
    Once again, let's output and exit. 3:42
    Now we need our application to actually use the .env file. 3:47
    In the inc directory, I have a file called bootstrap. 3:51
    This is where I have all the application details we need. 3:58
    Right now, it only contains the autoloader, but 4:01
    we'll add the .env object here as well, $dotenv = new Dotenv\Dotenv, 4:06
    and we'll give it the current directory. 4:13
    Because our .env file is within the ink folder as well. 4:20
    Then we need dotenv load. 4:26
    Now, let's go to our homepage and display this variable before the quote. 4:30
    Echo getenv SECRET. 4:40
    And let's take a look at the browser. 4:47
    All set, we can set and retrieve our own variables, so 4:55
    we're ready to start updating our application. 4:59
    You can go ahead and remove this display line. 5:03

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