WordPress syntax error: A perfect guide to fixing unexpected single-quoted string

Wordpress PHP errors may be caused by ghost spaces!

What programmers fear most is not bugs, but having their emotions toyed with by bugs.

The logic you wrote is obviously fine, but PHP gives you a syntax errorIt’s like you are three minutes late for a date, and the other person turns his face away and says “you don’t love me”. You feel so wronged that you want to throw the keyboard.

Why does WordPress PHP report an error?

The prompt given by PHP is:

syntax error, unexpected single-quoted string "wpturbo_handle_upload_convert_...", expecting ")"

Translated into human language, it means: I was expecting a closing bracket, but you stuffed a strange string of characters into me, with an inexplicable temperament.

So what's the problem? It's not your function logic, but that seemingly innocent line:

add_filter('wp_handle_upload', 'wpturbo_handle_upload_convert_to_webp');

Ghost spaces in code

The core of the problem is that when you copy and paste the code, you mix full width space Or Zero-width space.

These things are invisible to the naked eye in the editor, but will drive PHP crazy when it's parsed.

It's like eating a bowl of delicious noodles, but suddenly you bite into a grain of sand and your defenses are instantly broken. This is how PHP feels at the moment.

What is the correct way to write it?

What you need to do is actually very simple. Replace all those ghost spaces and keep the purest half-width spaces.

The correct WordPress code is as follows:

add_filter('wp_handle_upload', 'wpturbo_handle_upload_convert_to_webp');

function wpturbo_handle_upload_convert_to_webp($upload) {
    if (in_array($upload['type'], ['image/jpeg', 'image/png', 'image/gif'])) {
        $file_path = $upload['file'];
        if (extension_loaded('imagick') || extension_loaded('gd')) {
            $image_editor = wp_get_image_editor($file_path);
            if (!is_wp_error($image_editor)) {
                // Set WebP quality (adjust as needed)
                $quality = 80; // Adjust between 0 (low) to 100 (high)
                $image_editor->set_quality($quality);

                $file_info = pathinfo($file_path);
                $dirname = $file_info['dirname'];
                $filename = $file_info['filename'];
                $def_filename = wp_unique_filename($dirname, $filename . '.webp');
                $new_file_path = $dirname . '/' . $def_filename;

                $saved_image = $image_editor->save($new_file_path, 'image/webp');
                if (!is_wp_error($saved_image) && file_exists($saved_image['path'])) {
                    $upload['file'] = $saved_image['path'];
                    $upload['url']  = str_replace(basename($upload['url']), basename($saved_image['path']), $upload['url']);
                    $upload['type'] = 'image/webp';
                    @unlink($file_path);
                }
            }
        }
    }
    return $upload;
}

How to avoid this?

You might be wondering, do you have to be nervous every time you copy and paste? The answer is: don't panic, but be smart.

1. Use a reliable editor, such as VS Code, which can automatically highlight strange characters.
2. When opening a file, try saving it in UTF-8 encoding, which can reduce the risk of "ghost symbols" by half.
3. If you are really worried, paste the suspicious code into a plain text tool and clean it.

Just like washing the vegetables before eating hot pot, a lot of accidents can be avoided.

Conclusion

This error may seem mysterious, but its logic is actually very clear. Programming is like writing poetry; punctuation and spacing are the soul of rhythm. A single incorrect space can throw the code off-rhythm, like an out-of-tune tuba suddenly appearing in an orchestra.

When writing code, we must develop a kind of "symbol cleanliness". Only by achieving perfection in details can the logic run smoothly.哲学In a sense, this is also a pursuit of precision and order.

Final Thoughts

There are three key points:

• The error is not a logic problem, but a ghost space.
• The correct fix is ​​to replace it with a standard half-width space.
• Develop code cleanliness and stay away from hidden characters.

So, next time you encounter a seemingly inexplicable error, you might as well suspect: Is there an invisible "ghost" at work? Take action, clean them up, and your code will run smoothly.