Gravity Forms with AJAX, conditional logic, pages transitions (compatible with Barba.js, Taxi.js, Highway.js, ...)

README.md

The following code enables the use of Gravity Forms (2.8.7 as of now) with the following features:

• AJAX loading, 100% functional
• Functional with page transitions (Barba.js, Taxi.js, Highway.js)
• Enqueue Gravity Forms scripts used by each forms (including conditional logic scripts)
• Works with recaptcha (with recent version of Gravity Forms reCAPTCHA Add-On, scripts are automaticaly enqueued)
• Keep the form displayed after submission (optional)
• Scripts moved to footer (optional)

The code was initially integrated into projects using roots/sage. I adapted the code for integration into "vanilla" WordPress projects but I have less feedback compared to the use I have with my stack, so feel free to let me know if there are any errors in the comments!

form.php

<div class="js-gravity-form" data-id="<?php echo $formId ?>">
  <?php if (is_admin()) {
    echo gravity_form($formId, false, false, false, false, false, 0, false);
  }
  ?>
</div>

forms.js

// import { ScrollTrigger } from 'gsap/ScrollTrigger';

class Forms {
  constructor() {
    if (typeof jQuery === 'undefined') return;

    this.events();
    this.loadForms();
  }

  events() {
    document.addEventListener('gform_main_scripts_loaded', () => {
      if (typeof gform === 'undefined') return;
      gform.scriptsLoaded = !0;
      this.loadForms();
    });

    // (optional) Hooks related to form display after form submit
    jQuery(document).on('gform_post_render', (event, form_id, current_page) => {
      const formEl = document.querySelector(`.js-gravity-form.loaded[data-id="${form_id}"]`);
      if (formEl) {
        // Remove confirmation messages after form submit
        if (formEl.classList.contains('submitted')) {
          formEl.classList.remove('submitted');
        } else {
          const confirmationMessagesContainer = formEl.querySelector('.gform_confirmation_wrapper');

          if (confirmationMessagesContainer) {
            confirmationMessagesContainer.remove();
          }
        }

        // Remove empty divs after form submit
        const emptyDivs = formEl.querySelectorAll('.gform_custom_empty_div');
        emptyDivs.forEach((emptyDiv) => {
          emptyDiv.remove();
        });
      }
    });

    // (optional) Show form again after form submit
    jQuery(document).on('gform_confirmation_loaded', (event, formId) => {
      const ev = new CustomEvent('gform_submitted', { detail: { event, formId } });
      window.dispatchEvent(ev);

      const formEl = document.querySelector(`.js-gravity-form.loaded[data-id="${formId}"]`);
      if (formEl) {
        formEl.classList.add('submitted');

        const fields = formEl.querySelector('form').querySelectorAll('input:not([type=submit]):not([type=hidden]), textarea, select');
        fields.forEach((input) => {
          if (input.type === 'radio' || input.type === 'checkbox') {
            input.checked = '';
          } else {
            input.value = '';
          }
        });

        const wrapper = formEl.querySelector('.gform_wrapper');
        wrapper.style.removeProperty('display');

        this.loadFormHooks(formId);
      }
    });
  }

  loadForms() {
    if (typeof gform === 'undefined' || !gform.scriptsLoaded || !gform.domLoaded) return;

    const formContainers = document.querySelectorAll('.js-gravity-form');
    for (const formContainer of formContainers) {
      if (formContainer.classList.contains('loaded')) continue;
      formContainer.classList.add('loaded');

      const formId = formContainer.dataset.id;

      fetch(`${wp_vars.adminAjax}?action=gf_get_form&form_id=${formId}`, {
        method: 'GET',
        credentials: 'same-origin',
      })
        .then((res) => res.json())
        .then((datas) => {
          const html = datas.data;

          jQuery(formContainer).html(html);
          this.loadFormHooks(formId);
        
          // use it if you are using ScrollTrigger, ScrollSmoother, etc.
          // ScrollTrigger.refresh(); 

          const ev = new CustomEvent('gform_loaded', { detail: { formId } });
          window.dispatchEvent(ev);
        });
    }
  }

  loadFormHooks(formId) {
    jQuery(document).trigger('gform_post_render', [parseInt(formId), 0]);
    if (window.gformInitDatepicker) {
      window.gformInitDatepicker();
    }
    if (window.gformInitPriceFields) {
      window.gformInitPriceFields();
    }
  }
}

document.addEventListener("DOMContentLoaded", function() {
  gform.domLoaded = !0;
  new Forms();
});

functions.php

<?php



// [...]




/** GRAVITY FORMS RELATED FUNCTIONS & HOOKS **/

/**
 * Open numeric keypad on mobile for number fields in gravity forms
 * https://wire.gravityhopper.com/d/35-open-numeric-keypad-on-mobile-for-number-fields
 */
add_filter('gform_field_content', function ($content, $field, $value, $lead_id, $form_id) {
  if (wp_is_mobile() && ($field instanceof GF_Field_Number || $field instanceof GF_Field_Quantity)) {
    $content = str_replace("type='", "inputmode='decimal' type='", $content);
  }
  return $content;
}, 10, 5);


/**
 * Disable the native auto-scroll feature on form errors
 */
add_filter('gform_confirmation_anchor', '__return_false');


/**
 * Force add Gravity Forms hooks to all pages
 */
add_filter( 'gform_force_hooks_js_output', '__return_true' );


/**
 * (optional) Allow the Gravity form to stay on the page when confirmation displays.
 * Forked from https://gist.github.com/davidwolfpaw/0fa37230c9dbb197ed4a8bbc1c7e9547
 */
add_filter('gform_pre_submission_filter', 'gf_show_confirmation_and_form');
function gf_show_confirmation_and_form($form)
{
  // Inserts a shortcode for the form without title or description
  $shortcode = '[gravityform id="' . $form['id'] . '" title="false" description="false" ajax="true"]';

  // Ensures that new lines are not added to HTML Markup
  ob_start();
  echo do_shortcode($shortcode);
  $html = str_replace(array("\r", "\n"), '', trim(ob_get_clean()));
  $html = preg_replace('#<script(.*?)>(.*?)</script>#is', '', $html);
  $html = preg_replace('#<iframe(.*?)>(.*?)</iframe>#is', '', $html);

  // Inserts the form into parent div
  if (array_key_exists('confirmations', $form)) {
    $lastKey = array_key_last($form['confirmations']);
    $form['confirmations'][$lastKey]['message'] =  $form['confirmations'][$lastKey]['message'] . '</div></div>' . $html . '<div class="gform_custom_empty_div"><div>';
  }

  return $form;
}


/**
 * (optional) Move Gravity Forms scripts to footer
 */
add_filter('gform_init_scripts_footer', 'gform_init_scripts');
function gform_init_scripts() {
  return true;
}




/** AJAX **/

add_action('wp_ajax_nopriv_gf_get_form', 'gf_ajax_get_form');
add_action('wp_ajax_gf_get_form', 'gf_ajax_get_form');

function gf_ajax_get_form()
{
  if (!isset($_GET['form_id'])) {
    wp_send_json_error();
    exit;
  }
  $formId = absint($_GET['form_id']);
  wp_send_json_success( gravity_form($formId, false, false, false, false, true, 0, false) );
  exit;
}



/** ENQUEUE SCRIPTS */

function get_wp_variables() {
  return [
    'adminAjax' => admin_url('admin-ajax.php'),
  ];
}

wp_enqueue_script(
    'forms',
    get_stylesheet_directory_uri() . '/forms.js',
    array( 'jquery' )
);

wp_localize_script( 'forms', 'wp_vars', $get_wp_variables );

header_or_footer.php

<?php

/*
 * Choose to add this in header.php OR footer.php, depending on where you want to place your scripts and the hooks you've registered. 
 */

$forms = GFAPI::get_forms();

foreach ($forms as $form) {
    // Enqueue Gravity Forms scripts
    gravity_form_enqueue_scripts($form['id'], true);
  
    // Enqueue conditional logic for each forms (it also removes display:none on the form container if you have set up conditional logic on some fields)
    GFFormDisplay::register_form_init_scripts($form, [], true);
    GFFormDisplay::footer_init_scripts($form['id']);
}

I found this code in the form_display.php file of the Gravity Forms plugin.
What's quite surprising is that I don't see any place where the variable event is initialized. I might be mistaken (because it was a "quick" look), but it seems to me that the variable event is not initialized anywhere else.

It's also possible that this bug is caused by my use of hooks in the header/footer and/or in my JavaScript, and it may not be a case managed by Gravity Forms. I wouldn't be surprised if there are unhandled bugs related to this combination of using Gravity Forms via AJAX and the hooks called in my code. I haven't seen any documentation regarding the PHP hooks, I found them by myself.

Perhaps you could submit a bug report or contact Gravity Forms technical support about this code ? (https://www.gravityforms.com/open-support-ticket/technical/)

With this code, the bug will be resolved :

if (event && event.defaultPrevented)

Exactly!!! That's what I had concluded, that event was not initialized anywhere, hence the error. I have modified the plugin file and it works correctly. Thanks for your help @Striffly , I will write to support because it is indeed a bug.

Exactly!!! That's what I had concluded, that event was not initialized anywhere, hence the error. I have modified the plugin file and it works correctly. Thanks for your help @Striffly , I will write to support because it is indeed a bug.

You welcome 😉