Check missing fields using array_diff_key() in multilingual file alignment

How to use the array_diff_key() function to check missing fields in multilingual file comparison to ensure the integrity of language files?

Maintaining the integrity of language files is crucial when developing multilingual websites or applications. As the functionality increases, new fields may be added to the main language file, which may cause the corresponding fields to be missing in other language files. At this point, we need a way to check and ensure the integrity of all language files. PHP's array_diff_key() function can help us achieve this very well.

What is the array_diff_key() function?

The array_diff_key() function is used to compare keys of two or more arrays and returns an array containing all keys in the first array that are not in other arrays. This is very useful for checking for missing fields in language files. We can use it to compare keys for different language files, ensuring that each language file contains all the necessary fields.

Scene background

Suppose we have a main language file (such as English language file) and want to make sure that other language files (such as Chinese, French, etc.) do not have any missing fields. We can use array_diff_key() to compare the key values ​​of these files and find the missing fields.

Practical application: Check for missing fields

Suppose our language files are stored in an array, similar to the following structure:

English language files ( en.php ):

 return [
    'welcome_message' => 'Welcome to our website!',
    'login_button' => 'Login',
    'logout_button' => 'Logout',
    'contact_us' => 'Contact Us'
];

Chinese language files ( zh.php ):

 return [
    'welcome_message' => 'Welcome to our website！',
    'login_button' => 'Log in',
    // 'logout_button' => 'Log out', It's missing here 'logout_button' Fields
];

Now we want to compare these two language files through array_diff_key() to find out the missing fields in the Chinese file.

Use array_diff_key() to compare language files

 // Load English and Chinese language files
$en = include('en.php');
$zh = include('zh.php');

// Comparing the keys of Chinese language files with English language files，找出缺失的Fields
$missingFields = array_diff_key($en, $zh);

// 输出缺失的Fields
if (!empty($missingFields)) {
    echo "以下Fields在中文语言文件Missing：\n";
    foreach ($missingFields as $key => $value) {
        echo "- $key\n";
    }
} else {
    echo "中文语言文件没有缺失任何Fields。\n";
}

Code explanation

1. Loading language files : Use include() to load en.php and zh.php files, which store translation data in key-value pair formats.

2. Call array_diff_key() : Compare the keys of English and Chinese language files through array_diff_key($en, $zh) . array_diff_key() returns an array containing keys that are in the English language file but not in the Chinese language file.

3. Output missing fields : If the returned $missingFields array is not empty, it means that some fields are missing in the Chinese language file. We output these missing fields by looping.

Check multiple language files

If we need to check the integrity of multiple language files, we can use a similar approach to compare each language file with the main language file to ensure that all fields are translated. For example, we can encapsulate the check logic into a function:

 function checkMissingFields($primaryLangFile, $compareLangFile) {
    $primaryLang = include($primaryLangFile);
    $compareLang = include($compareLangFile);

    $missingFields = array_diff_key($primaryLang, $compareLang);

    if (!empty($missingFields)) {
        echo "以下Fields在 $compareLangFile Missing：\n";
        foreach ($missingFields as $key => $value) {
            echo "- $key\n";
        }
    } else {
        echo "$compareLangFile 没有缺失任何Fields。\n";
    }
}

// Comparison of English and Chinese documents
checkMissingFields('en.php', 'zh.php');

// Comparison of English and French documents
checkMissingFields('en.php', 'fr.php');

summary

Using PHP's array_diff_key() function, we can efficiently check missing fields in multilingual files. This ensures that files in different languages ​​are consistent and avoids incomplete interface display due to translation omissions. In this way, the quality and maintainability of multilingual projects can be greatly improved.