How to make fields required programatically in Contact Form 7

In this guide, you will learn how to create custom validation in CF7. This guide is also the solution for programmatically making fields required.

Contact Form 7 uses the validation server-side, which means we need to hook into the PHP functions/filters in order to create custom validations.

In my scenario, I have a select field called type-of-enquiry with 2 options, Sales and Support.

If sales is selected, I am showing and validating country(select) and state(select), if support is selected, I am showing product(select), telephone(tel) and subject(text).

We start off by creating a custom file in our theme or child theme, I’ve named mine “cf7-custom-validation.php” and saved it in a custom folder called “inc” and we import it in our functions.php file using:

functions.php

require_once( get_template_directory() . '/inc/cf7-custom-validation.php' );
Code language: PHP (php)

cf7-custom-validation.php

<?php // Block direct access to the file defined( 'ABSPATH' ) || exit; /** * Each field type has its own validation filter, * so we create a function for each type */ add_filter( 'wpcf7_validate_select', 'wpharvest_custom_validation_select', 20, 2 ); add_filter( 'wpcf7_validate_tel', 'wpharvest_custom_validation_tel', 20, 2 ); add_filter( 'wpcf7_validate_text', 'wpharvest_custom_validation_text', 20, 2 ); /** * Go through all the select fields */ function wpharvest_custom_validation_select( $result, $tag ) { // Get the type of enquiry from the dropdown $enquiryType = isset( $_POST['type-of-enquiry'] ) ? trim( $_POST['type-of-enquiry'] ) : ''; // If selection is Sales if( $enquiryType == 'Sales' ){ // If current validation is your-country and is empty then invalidate field if ( 'your-country' == $tag->name && empty( $_POST['your-country'] ) ) { $result->invalidate($tag, "This field is required."); } // We can also make validation dependent on other fields // If current validation is state, the country selected is United States and is empty then invalidate field if ( 'state' == $tag->name && trim( $_POST['your-country'] ) == 'United States' && empty( $_POST['state'] ) ) { $result->invalidate($tag, "This field is required."); } } // If selection is Support if( $enquiryType == 'Support' ){ // If current validation is product and is empty then invalidate field if ( 'product' == $tag->name && empty( $_POST['product'] ) ) { $result->invalidate($tag, "This field is required."); } } return $result; } /** * Go through all the tel fields */ function wpharvest_custom_validation_tel( $result, $tag ) { // Get the type of enquiry from the dropdown $enquiryType = isset( $_POST['type-of-enquiry'] ) ? trim( $_POST['type-of-enquiry'] ) : ''; // If selection is Support if( $enquiryType == 'Support' ){ // If current validation is telephone and is empty then invalidate field if ( 'telephone' == $tag->name && empty( $_POST['telephone'] ) ) { $result->invalidate($tag, "This field is required."); } } return $result; } /** * Go through all the text fields */ function wpharvest_custom_validation_text( $result, $tag ) { // Get the type of enquiry from the dropdown $enquiryType = isset( $_POST['type-of-enquiry'] ) ? trim( $_POST['type-of-enquiry'] ) : ''; // If selection is Support if( $enquiryType == 'Support' ){ // If current validation is subject and is empty then invalidate field if ( 'subject' == $tag->name && empty( $_POST['subject'] ) ) { $result->invalidate($tag, "This field is required."); } } return $result; }
Code language: HTML, XML (xml)