[WordPress] Sanitization Classes of the WordPress Settings API

1-address-setting.php

<?php

class Address_Setting {

	/**
 	 * A custom sanitization function that will take the incoming input, and sanitize
 	 * the input before handing it back to WordPress to save to the database. 
 	 * If the input is not valid, then the data will not be saved and an error 
 	 * message will be added to WordPress' error collection.
  	 *
  	 * @since    1.0.0
  	 *
  	 * @param    array    $input        The address input.
  	 * @return   mixed    $new_input    The sanitized input or false (to prevent the data from saving)
  	 */
 	public function sanitize( $input ) {

		$new_input = false;

		$validator = new Address_Validator( $this );
		if ( $validator->is_valid( $input ) ) {
			
			$new_input = array();
			foreach ( $input as $key => $val ) {
				$new_input[ $key ] = sanitize_text_field( $val );
			}
			
		}
		
		return $new_input;
	
 	}
 	
}

2-city-setting.php

<?php

class City_Setting {

	/**
 	 * A custom sanitization function that will take the incoming input, and sanitize
 	 * the input before handing it back to WordPress to save to the database. 
 	 * If the input is not valid, then the data will not be saved and an error 
 	 * message will be added to WordPress' error collection.
  	 *
  	 * @since    1.0.0
  	 *
  	 * @param    array    $input        The city input.
  	 * @return   mixed    $new_input    The sanitized input or false (to prevent the data from saving)
  	 */
 	public function sanitize( $input ) {

		$new_input = false;

		$validator = new Postal_Code_Validator( $this );
		if ( $validator->is_valid( $input ) ) {
			
			$new_input = array();
			foreach ( $input as $key => $val ) {
				$new_input[ $key ] = sanitize_text_field( $val );
			}
			
		}
		
		return $new_input;
	
 	}
 	
}

3-postal-code-setting.php

<?php

class Postal_Code_Setting {

	/**
 	 * A custom sanitization function that will take the incoming input, and sanitize
 	 * the input before handing it back to WordPress to save to the database. 
 	 * If the input is not valid, then the data will not be saved and an error 
 	 * message will be added to WordPress' error collection.
  	 *
  	 * @since    1.0.0
  	 *
  	 * @param    array    $input        The city input.
  	 * @return   mixed    $new_input    The sanitized input or false (to prevent the data from saving)
  	 */
 	public function sanitize( $input ) {

		$new_input = false;

		$validator = new Postal_Code_Validator( $this );
		if ( $validator->is_valid( $input ) ) {
			
			$new_input = array();
			foreach ( $input as $key => $val ) {
				$new_input[ $key ] = sanitize_text_field( $val );
			}
			
		}
		
		return $new_input;
	
 	}
 	
}