How to ensure code quality in PHP

Some ways to improve code quality in php

1. Do not use relative paths

We often see:

require_once('../../lib/some_class.php');

This method has many shortcomings:

It first looks for the specified php include path, then looks for the current directory, so too many paths are checked. If the script is included by a script in another directory, its base directory becomes the directory where the other script is located. Another problem is that when the scheduled task runs the script, its parent directory may not be the working directory.

So the best option is to use an absolute path:

define('ROOT' , '/var/www/project/');
require_once(ROOT . '../../lib/some_class.php');
//rest of the code

We define an absolute path and the value is written Dead. We can still improve it. The path /var/www/project may also change, so do we have to change it every time? No, We can use the __FILE__ constant, such as:

//suppose your script is /var/www/project/index.php
//Then __FILE__ will always have that full path.
define('ROOT' , pathinfo(__FILE__, PATHINFO_DIRNAME));
require_once(ROOT . '../../lib/some_class.php');
//rest of the code

Now, no matter which directory you move to, such as moving to an external server, the code will run correctly without any changes.

#2. Do not use require, include, include_once, required_once directly

can be used in the script head Introduce multiple files, such as class libraries, tool files and helper functions, such as:

require_once('lib/Database.php');
require_once('lib/Mail.php');
require_once('helpers/utitlity_functions.php');

This usage is quite primitive. It should be more flexible. A helper function should be written Include the file. For example:

function load_class($class_name)
{
//path to the class file
$path = ROOT . '/lib/' . $class_name . '.php');
require_once( $path );
}
load_class('Database');
load_class('Mail');

What's the difference? The code is more readable. In the future you can extend the function as needed, like:

function load_class($class_name)
{
//path to the class file
$path = ROOT . '/lib/' . $class_name . '.php');
if(file_exists($path))
{
require_once( $path );
}
}

You can do more:

Find multiple directories for the same file and easily change the directory where class files are placed. , there is no need to modify the code one by one, you can use similar functions to load files, such as html content.

3. Keep debugging code for the application

In the development environment, we print the database query statement and dump the problematic variable values. And once the problem is solved, we comment or delete them. However a better approach is to keep the debug code. In the development environment, you can:

define('ENVIRONMENT' , 'development');
if(! $db->query( $query )
{
if(ENVIRONMENT == 'development')
{
echo "$query failed";
}
else
{
echo "Database error. Please contact administrator";
}
}

In the server, you can:

define('ENVIRONMENT' , 'production');
if(! $db->query( $query )
{
if(ENVIRONMENT == 'development')
{
echo "$query failed";
}
else
{
echo "Database error. Please contact administrator";
}
}

Recommended tutorial:

PHP video tutorial

The above is the detailed content of How to ensure code quality in PHP. For more information, please follow other related articles on the PHP Chinese website!