WordPress: How to Remove and Prevent Line Feeds and Carriage Returns in Titles

You may have encountered line feeds or carriage returns inserted into the post titles when creating or editing in WordPress. These extra characters can cause formatting issues and make your titles appear inconsistent. In this article, I’ll provide two methods to remove line feeds and carriage returns from your WordPress post titles: a MySQL solution to fix previously written titles and a PHP function to prevent the issue from occurring in the future.

Method 1: MySQL Solution for Previously Written Titles

If you have existing posts with line feeds or carriage returns in their titles, you can use a MySQL query to update them all at once. Here’s the query:

UPDATE wp_posts
SET post_title = REGEXP_REPLACE(post_title, '(\\w)\\r?\\n(\\w)', '$1 $2')
WHERE post_status = 'publish';

The MySQL query provided in the article uses the REGEXP_REPLACE() function, which is available in MySQL 8.0 and later versions. Therefore, to use the MySQL solution as-is, your server must have MySQL 8.0 or above installed.

• The UPDATE statement is used to modify the data in the wp_posts table.
• The SET clause specifies the column we want to update, which is post_title.
• We use the REGEXP_REPLACE() function to perform a regular expression replacement on the post_title column. This function is available in MySQL 8.0 and later versions.
• The regular expression pattern '(\\w)\\r?\\n(\\w)' matches a word character, followed by an optional carriage return, a line feed, and another character. The double backslashes are used to escape the backslash in the MySQL query.
• The replacement pattern '$1 $2' replaces the matched pattern with the captured word characters separated by a space.
• The WHERE clause filters the rows to update only the post titles where the post_status is ‘publish’. Adjust this condition if you want to include drafts and other post statuses.

If you are using an older version of MySQL (prior to 8.0), you can achieve a similar result by using a combination of REGEXP_SUBSTR() and CONCAT() functions instead. Here’s an alternative query that works with older MySQL versions:

UPDATE wp_posts
SET post_title = CONCAT(
    REGEXP_SUBSTR(post_title, '^[^\\r\\n]+'),
    IF(REGEXP_SUBSTR(post_title, '\\r?\\n'), ' ', ''),
    REGEXP_SUBSTR(post_title, '[^\\r\\n]+$')
)
WHERE post_status = 'publish';

Explanation:

• The CONCAT() function is used to concatenate the parts of the post title.
• The first REGEXP_SUBSTR() function extracts the part of the title before any line feeds or carriage returns.
• The IF() function checks if there are any line feeds or carriage returns in the title. If found, it adds a space; otherwise, it adds an empty string.
• The second REGEXP_SUBSTR() function extracts the part of the title after any line feeds or carriage returns.

Before running the query, make sure to replace wp_posts with your actual WordPress posts table name and back up your database as a precaution.

Method 2: Child Theme Function to Prevent Future Occurrences

To prevent line feeds and carriage returns from being saved in post titles moving forward, you can add a PHP function to your WordPress child theme’s functions.php file. Here’s the function:

function remove_line_feeds_from_post_title($data, $postarr) {
    if (isset($data['post_title'])) {
        $data['post_title'] = preg_replace('/(\w)\r?\n(\w)/', '$1 $2', $data['post_title']);
    }
    return $data;
}
add_filter('wp_insert_post_data', 'remove_line_feeds_from_post_title', 10, 2);

Explanation:

• The function is named remove_line_feeds_from_post_title and takes two parameters: $data (the post data array) and $postarr (the raw post data).
• Inside the function, we check if the post_title key exists in the $data array using the isset() function.
• If the post_title key exists, we use the preg_replace() function to replace any occurrences of line feeds or carriage returns between word characters with a space.
• The regular expression pattern '/(\w)\r?\n(\w)/' matches a word character, followed by an optional carriage return and a line feed, and then another word character.
• The replacement pattern '$1 $2' replaces the matched pattern with the captured word characters separated by a space.
• Finally, we return the modified $data array.
• We use the add_filter() function to hook our custom function to the wp_insert_post_data filter, which is triggered before the post data is inserted into the database.

With this function in place, whenever a post is saved or updated, any line feeds or carriage returns within the post title will be automatically removed or replaced with spaces before saving to the database.

By using the MySQL query to fix existing post titles and adding the PHP function to your child theme, you can ensure that your WordPress post titles are free from unwanted line feeds and carriage returns, maintaining a consistent and clean appearance on your website.