How to build multilingual web applications using PHP

With the popularity of the Internet, more and more web applications need to support multiple languages ​​​​to meet the needs of global users. PHP is a popular server-side scripting language that helps us build multilingual web applications. In this article, we will introduce how to use PHP to implement multilingual web applications, including how to read and manage different language files, how to switch languages, and how to use multiple languages ​​in dynamic web pages.

Step One: Create Language Files

The first step in creating a multilingual web application is to create text files in different languages. In these files we will store all the text strings we want to use in the web application. For example, if our web application contains a login form, we will create a text file containing English and Chinese strings respectively. File naming conventions can be language-based or application locale-based, such as "en.txt" and "zh-CN.txt".

In text files, we need to use a certain format to store text strings. For example, in an English text file, we will store the label and button text of the login form using the following format:

login_label = Login
password_label = Password
login_button = Login

In a Chinese text file, we will store the same text string using the following format:

login_label = 登录
password_label = 密码
login_button = 登录

When creating text files, we need to ensure that each text string has the same key name so that we can easily switch between different languages.

Step Two: Read and Manage Language Files

Once we have created text files in different languages, the next step is to read and manage these files. In PHP, we can easily read text files using "file_get_contents" and "json_decode" functions. For example, the following code snippet will read an English text file and convert it into a PHP array:

$lang = 'en';
$file = 'lang/'.$lang.'.txt';
$text = file_get_contents($file);
$strings = json_decode($text, true);

In this example, we first specify which language's text file we want to read (here, English). We then read the file contents using the "file_get_contents" function and convert them into a PHP array using the "json_decode" function.

In the same way, we can read text files in other languages. Once we have read all the language files, we can save them in a multidimensional array and use the key names to access specific text strings. This allows us to easily switch between different languages ​​by simply changing the language identifier.

Step Three: Switch Language

Switching languages ​​is an important part of building multilingual web applications. In PHP we can use session variables or cookies to save user language selection. Here is an example of using session variables to implement language switching:

session_start();

if (isset($_GET['lang'])) {
    $_SESSION['lang'] = $_GET['lang'];
}

if (!isset($_SESSION['lang'])) {
    $_SESSION['lang'] = 'en';
}

In this example, we first start the session and check whether the "lang" parameter is set. If set, the value of the "lang" parameter will be saved in the session variable. If not set, "en" will be set as the default language.

Additionally, we can select language-specific text strings based on session variables. For example, the following code snippet will display the text string for the login form:

$lang = $_SESSION['lang'];
$text = $strings[$lang];
echo $text['login_label'];
echo $text['password_label'];
echo $text['login_button'];

Here, we first select the correct array of text strings using the language selection in the session variable. We then use the array keys to select specific text strings and output them.

Step 4: Use multi-language in dynamic web pages

When using multi-language, we need to ensure that every text string in the web page is translatable and will They are stored in text files. A common way to use multiple languages ​​in dynamic web pages is to use PHP functions. For example, the following code snippet will display a login form and background image in a web page, which are different text strings and image files based on the selected language:

<div class="form-group">
    <label for="username"><?php echo $text['login_label']; ?></label>
    <input type="text" name="username" class="form-control" id="username">
</div>
<div class="form-group">
    <label for="password"><?php echo $text['password_label']; ?></label>
    <input type="password" name="password" class="form-control" id="password">
</div>
<button type="submit" class="btn btn-primary"><?php echo $text['login_button']; ?></button>
<img  src="<?php echo $image_path.'/'.$lang.'/background.jpg'; ? alt="How to build multilingual web applications using PHP" >">

In this example, we are in a web page A PHP "echo" statement is used around each text string. This will cause the PHP interpreter to interpret them and replace them with the correct text strings. In the same way, we can use the same approach to multilingualism elsewhere.

Summary

In this article, we introduced how to build multilingual web applications using PHP. We learned how to create, read, and manage language files, how to switch languages, and how to use multiple languages ​​in dynamic Web pages. The way to use PHP is very simple, you just need to understand the basic concepts and follow the correct steps. We hope this article helps you build your own multilingual web applications.

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