Description: A minimal form storage plugin for developers

Fern Form

A lightweight WordPress plugin for handling form submissions for developers. This plugin is made to work with the Fern framework (WIP).

Features

• Data Retention: Configurable retention period for form submissions to prevent database bloat
• Notification System: Visual notifications for unread form submissions
• Developer Friendly: Extensive hooks and filters for customization
• Zero table creation: This plugin use the native WordPress post type & terms to store the form submissions.

Be aware that this plugin use the post table to store the form submissions.

Submissions are cleaned up by a daily wordpress cron job. If you disable the WP_CRON, the form submissions will not be deleted which could increase the post table size.

Default cleanup is set to 7 day after creation date.

Set retention_days to a negative number to keep submissions forever and disable the cleanup entirely. Zero deletes everything older than the moment the cron runs.

Requirements

• WordPress 6.0 or higher
• PHP 8.0 or higher

Installation

1. Download the plugin from the GitHub releases.
2. Upload the plugin folder to the /wp-content/plugins/ directory.
3. Activate the plugin through the 'Plugins' menu in WordPress.

Or, use composer, first edit the composer.json file to add the plugin install path :

{
  ...
  "extra": {
    "installer-paths": {
      "public/content/plugins/fern-form/": [
        "fern/form"
      ],
    }
  }

Then, run the following command:

composer require fern/form

Then, the plugin will be installed in the public/content/plugins/fern-form directory.

Basic Usage

Basic Form Submission

// needs to be called after init hook
fern_form_store('contact_form', [
  'name' => 'John Doe',
  'email' => 'john@doe.com',
  'message' => 'Hello, world!'
]);

// or using the class
use Fern\Form\Includes\FormSubmission;

$formSubmission = new FormSubmission('contact_form', [
  'name' => 'John Doe',
  'email' => 'john@doe.com',
  'message' => 'Hello, world!'
]);

$entryId = $formSubmission->store();

Then, the form data will be stored in the database and visible in the admin dashboard.

Updating a submission

$submissionId = 123;

// needs to be called after init hook
fern_form_update($submissionId, [
  'name' => 'John Doe',
  'email' => 'john@doe.com',
  'message' => 'Hello, world! (again)'
]);

Deleting a submission

$submissionId = 123;
// needs to be called after init hook
fern_form_delete($submissionId);

Getting a submission

$submissionId = 123;
$submission = fern_form_get_submission_by_id($submissionId);

if (is_null($submission)) {
  return;
}

// do something with the submission

Configuration

You can configure the plugin by hooking into the fern:form:config filter.

The filter is applied the first time the configuration is read, which happens on init at the earliest. A theme's functions.php is therefore late enough:

add_filter('fern:form:config', function(array $config): array {
  return [
    // After 30 days, submissions will be deleted
    'retention_days' => 30,
    // Set the capabilities for the form post type
    'form_capabilities' => [
      'create' => 'edit_posts',
      'read' => 'read',
      'delete' => 'delete_posts'
    ]
  ];
});

// Keep every submission: no cleanup, ever.
add_filter('fern:form:config', function(array $config): array {
  $config['retention_days'] = -1;
  return $config;
});

// Disable default admin styles
define('FERN_FORM_ASSETS', false);

Returning only the keys you care about is supported — anything you leave out falls back to the default.

 Hooks references

You can extend the plugin functionality by hooking into the following actions and filters.

Actions

fern:form:submission_stored

Triggered after successful submission storage

/**
 * @param int    $post_id     The ID of the newly created submission post
 * @param string $form_name   The sanitized form name/slug
 * @param array  $submission  The complete submission data array
 */
add_action('fern:form:submission_stored', function($post_id, $form_name, $submission) {
  // Example: Send email notification
  wp_mail(
    'admin@example.com',
    "New submission from {$form_name}",
    "Submission ID: {$post_id}"
  );
}, 10, 3);

fern:form:submission_error

Triggered on submission error

/**
 * @param WP_Error $error       The WordPress error object
 * @param string   $form_name   The sanitized form name/slug
 * @param array    $submission  The submission data that failed to store
 */
add_action('fern:form:submission_error', function($error, $form_name, $submission) {
  // Example: Log the error
  error_log("Form submission failed for {$form_name}: " . $error->get_error_message());
}, 10, 3);

fern:form:before_delete

Triggered before deleting a submission

/**
 * @param int    $id         The submission post ID
 * @param string $form_name  The form name/slug
 */
add_action('fern:form:before_delete', function($id, $form_name) {
  // Custom logic before deletion
});

fern:form:after_delete

Triggered after successful deletion

/**
 * @param int    $id         The deleted submission ID
 * @param string $form_name  The form name/slug
 */
add_action('fern:form:after_delete', function($id, $form_name) {
  // Post-deletion processing
});

fern:form:update_submission_error

Triggered on update submission error

/**
 * @param int    $id         The submission ID
 * @param string $form_name  The form name/slug
 * @param array  $submission The submission data
 */
add_action('fern:form:update_submission_error', function($id, $form_name, $submission) {
  error_log("Update failed for submission {$id}");
});

fern:form:submission_updated

Triggered after successful update

/**
 * @param int    $id         The submission ID
 * @param string $form_name  The form name/slug
 * @param array  $submission The updated data
 */
add_action('fern:form:submission_updated', function($id, $form_name, $submission) {
  // Post-update processing
});

Filters

fern:form:config

Modify plugin configuration

/**
 * @param array $config Default configuration array
 * @return array Modified configuration
 */
add_filter('fern:form:config', function($config) {
  $config['retention_days'] = 60;
  $config['form_capabilities'] = [
    'create' => 'custom_cap',
    'read' => 'read_forms',
    'delete' => 'delete_forms'
  ];
  return $config;
});

fern:form:submission_should_abort

Allow aborting the submission

/**
 * @param bool $shouldAbort
 * @param string $formName
 * @param array $submission
 * @return bool
 */
add_filter('fern:form:submission_should_abort', function($shouldAbort, $formName, $submission) {
  $shouldAbort = ReCaptchaV3::validate($submission['recaptcha_token']);
  return $shouldAbort;
});

fern:form:submission_data

Modify submission data before storage

/**
 * @param array $submission The submission data array
 * @return array Modified submission data
 */
add_filter('fern:form:submission_data', function($submission) {
  // Example: Add timestamp
  $submission['submitted_at'] = current_time('mysql');
  return $submission;
});

fern:form:submission_title

Customize submission title format (in admin list view)

/**
 * @param string $default_title Default title format
 * @param string $form_name     The form name/slug
 * @param array  $submission    The complete submission data
 * @return string Modified title
 */
add_filter('fern:form:submission_title', function($default_title, $form_name, $submission) {
  if (!empty($submission['email'])) {
    return $submission['email'];
  }

  return $default_title;
}, 10, 3);

fern:form:update_submission_should_abort

Allow aborting the update submission

/**
 * @param bool   $should_abort Whether to abort
 * @param string $form_name    The form name/slug
 * @param array  $submission   The submission data
 * @return bool
 */
add_filter('fern:form:update_submission_should_abort', function($should_abort, $form_name, $submission) {
  return $should_abort || !current_user_can('edit_posts');
});

fern:form:update_submission_data

Modify submission data before update

/**
 * @param array $submission The submission data
 * @return array Modified data
 */
add_filter('fern:form:update_submission_data', function($submission) {
  $submission['updated_at'] = current_time('mysql');
  return $submission;
});

fern:form:update_submission_title

Customize submission title format (in admin list view)

/**
 * @param string $current_title Current post title
 * @param string $form_name     The form name/slug
 * @param array  $submission    The submission data
 * @return string New title
 */
add_filter('fern:form:update_submission_title', function($current_title, $form_name, $submission) {
  return $current_title . ' (Updated)';
});

fern:form:delete_submission_should_abort

Allow aborting the delete submission

/**
 * @param bool   $should_abort Whether to abort
 * @param string $form_name    The form name/slug
 * @param array  $submission   The submission data
 * @return bool
 */
add_filter('fern:form:delete_submission_should_abort', function($should_abort, $form_name, $submission) {
  return $should_abort || !current_user_can('delete_posts');
});

fern:form:submission_item_key

Filter the display key of a submission item.

/**
 * @param string $display_key The formatted key to display
 * @param string $full_key    The original full key path
 * @return string
 */
add_filter('fern:form:submission_item_key', function($display_key, $full_key) {
  // Example: Translate specific keys
  if ($full_key === 'user_email') {
    return __('Email Address', 'text-domain');
  }
  return $display_key;
}, 10, 2);

fern:form:submission_item_value

Filter the display value of a submission item.

/**
 * @param string $value       The value to display
 * @param string $display_key The formatted key
 * @param string $full_key    The original full key path
 * @return string
 */
add_filter('fern:form:submission_item_value', function($value, $display_key, $full_key) {
  // Example: Mask sensitive data
  if (strpos($full_key, 'password') !== false) {
    return '********';
  }
  return $value;
}, 10, 3);

 Uninstall

The plugin will automatically remove all data when uninstalled if the FERN_CLEAR_ON_DEACTIVATE constant is set to true.

define('FERN_CLEAR_ON_DEACTIVATE', true);

Otherwise, data will be preserved.