PHP: Using a variable from an external file in my class

Question

I have a settings.php file that looks something like this:

$user="adam";
$pass="something";

then I have a class called funcs.php, in which I have a require "../settings.php" on top, but I don't know how to get the scope of "$user" into my methods...

I'm sure this is an easy fix, but I've been googling in circles for a while with no luck.

My class looks something like this:

<?php
require_once __DIR__."/../settings.php";

class Funcs
{

    public function something()
    {
        // do stuff
return $user;

    }
}

See my answer here and my blogpost here, use a configuration container and insert that into your methods. — Daniel W.
– Daniel W., Commented May 3, 2014 at 1:29

Ryan · Accepted Answer · 2014-05-03 01:32:32Z

2

you can use the return construct inside file which can return anything, but if you want to return multiple values, it's best to use an array.

settings.php

return array(
  'user' => 'adam',
  'pass' => 'something'
);

file.php

$settings = require __DIR__.'settings.php';

echo $settings['user']; // adam

To pass everything returned from the file into a class:

class MyClass {
  public function __construct(array $array) {
    foreach($array as $key => $value) {
      $this->{$key} = $value;
    }
  }
}

$class = new MyClass(require __DIR__ . '/settings.php');
var_dump($class);
/*
 class MyClass#1 (2) {
  public $user =>
  string(4) "adam"
  public $pass =>
  string(9) "something"
}
*/

edited May 3, 2014 at 1:32

answered May 3, 2014 at 1:19

Ryan

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9 Comments

Ryan Over a year ago

Isn't it possible to declare a variable in the class, set its value to the $user from settings, and then refer to it as $this->variable_name? (I just dont remember how to do it...)

Ryan Over a year ago

Yes. Tell me the class name and I can show you how.

Ryan Over a year ago

settings.php - the file with all the variables. Funcs.php - the class.

Ryan Over a year ago

@Ryan take a look at what I provided, and let me know if that is what you mean.

Ryan Over a year ago

Not really, because you are passing it in the constructor... I thought by having an include in the top of the class file I could avoid having a constructor in the class

|

thexacre · Accepted Answer · 2014-05-03 01:36:05Z

2

I think the issue is that these are global variables used inside a function or class scope.

If you want to access these from within a function scope you could use the "global" keyword, for example:

public function foo() {
    global $user;
    echo $user;
}

However – using global (and global variables in general) is usually considered pretty smelly these days.

Some alternatives:

Pass the configuration into the constructor of your class, therefore:

$config = array(
    'user' => 'adam',
    'pass' => 'something'
);

class MyConsumer {
    private $config;

    public function __construct($config) {
        $this->config = $config;
    }
}

$instance = new MyConsumer($config);

This is usually termed "dependency injection", because your config can be easily substituted for something else depending on the context (such as in unit tests).

An alternative is to have a singleton class which encapsulates your config, which you'd access something like (not tested but you get the idea):

// production_config.php
return array(
    'user' => 'adam',
    'password' => 'something'
);
// config.php
class Config {
    protected $config;
    protected static $instance = null;

    protected function __construct() {
        $this->config = require('production_config.php');
    }

    protected function getKey($key) {
        if(isset($this->config[$key])) {
            return $this->config[$key];     
        }
        // Possibly throw exception or something else if not found
    }

    public static function get($key) {
        if(self::$instance === null) {
            self::$instance = new self();       
        }
        return self::$instance->getKey($key);
    }

}

So you can go:

$user = Config::get('user');

This is perhaps easier than passing your config into every class, but it's more difficult to substitute your config for testing purposes.

edited May 3, 2014 at 1:36

answered May 3, 2014 at 1:24

thexacre

7024 silver badges9 bronze badges

7 Comments

Ryan Over a year ago

Where is Config defined?

Ryan Over a year ago

Yep, I don't want to use Globals nor do I want to pass it via the constructor as what I wrote above was just an example, I have a lot of variables in that file that I want to use in my classes...

thexacre Over a year ago

In another class, typically you'd "include" it to your global scope either when you bootstrap the application (if you have a central entry point) or by including it in your global includes on every page.

thexacre Over a year ago

I'll add an example of a config singleton to my answer.

Ryan Over a year ago

Thanks for taking the time to write all that, but I have never worked with singletons, and I think I have some reading to do!

|

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