Sanitization

In WordPress development, sanitization refers to the process of cleaning or escaping user inputs (such as form data) before storing or using them, to prevent security vulnerabilities like Cross-Site Scripting (XSS) or SQL injection attacks. It ensures that only safe and valid data is accepted by your application, safeguarding your website against potential exploits.

Key Concepts of Sanitization:

1. Sanitizing Data: This process cleans input data to ensure it meets expected formats or removes any harmful characters. It’s usually done right after receiving the input, before using or storing it.
2. Escaping Data: This process ensures that data is safe to output in an HTML context, preventing it from being interpreted as executable code.

Common WordPress Functions for Sanitization:

1. Sanitizing Text Fields:
   
   $clean_text = sanitize_text_field( $_POST['text_input'] );
   • sanitize_text_field() strips out HTML tags and removes potentially harmful characters.
2. Sanitizing Email Fields:
   
   $clean_email = sanitize_email( $_POST['email_input'] );
   • sanitize_email() validates and removes invalid characters from an email address.
3. Sanitizing URLs:
   
   $clean_url = esc_url( $_POST['url_input'] );
   • esc_url() sanitizes a URL, ensuring it follows proper formatting.
4. Sanitizing HTML:
   
   $clean_html = wp_kses_post( $_POST['html_input'] );
   • wp_kses_post() allows only a specific set of HTML tags and attributes (the same set allowed in WordPress posts) while stripping out others.
5. Sanitizing Integers:
   
   $clean_number = intval( $_POST['number_input'] );
   • intval() ensures the input is an integer value.

Escaping Output:

When displaying sanitized data in a theme or plugin, it’s crucial to escape it to ensure it’s safely output in an HTML context.

• For URLs: echo esc_url( $url );
• For HTML Attributes: echo esc_attr( $attribute );
• For Text in HTML: echo esc_html( $text );

Summary:

• Sanitization happens before storing or using data (input validation).
• Escaping happens before outputting data (output security).

By combining these techniques, you ensure the safety and integrity of your WordPress applications. Do you need help with a specific sanitization case in WordPress?