Core Forms provides an extensive set of actions and filters for developers to customize every aspect of form rendering, processing, and administration.
Form Rendering Filters
cf_form_html
Filters the complete HTML output of a form, including the <form> tag, hidden fields, and wrapper elements.
add_filter( 'cf_form_html', function( $html, $form ) {
return $html;
}, 10, 2 );Parameters:
$html(string) – The complete form HTML.$form(Form) – The Form object.
cf_form_markup
Filters the inner form markup (the content you write in the Fields tab), before it is wrapped in the form element.
add_filter( 'cf_form_markup', function( $markup, $form ) {
return $markup;
}, 10, 2 );Parameters:
$markup(string) – The form field markup HTML.$form(Form) – The Form object.
cf_form_element_class_attr
Filters the CSS class string added to the <form> element.
add_filter( 'cf_form_element_class_attr', function( $classes, $form ) {
return $classes . ' my-custom-class';
}, 10, 2 );cf_form_element_action_attr
Filters the action attribute of the <form> element. By default, this is null (no action attribute), and the form submits via AJAX.
add_filter( 'cf_form_element_action_attr', function( $action, $form ) {
return $action;
}, 10, 2 );cf_form_element_data_attributes
Filters the array of data attributes added to the <form> element.
add_filter( 'cf_form_element_data_attributes', function( $attributes, $form ) {
$attributes['custom'] = 'value';
return $attributes;
}, 10, 2 );cf_form_message_{code}
Filters a specific form message. The {code} is the message key (e.g., success, error, required_field_missing).
add_filter( 'cf_form_message_success', function( $message, $form ) {
return 'Thanks! Got it.';
}, 10, 2 );cf_form_default_messages
Filters the array of default messages for all forms.
add_filter( 'cf_form_default_messages', function( $messages ) {
$messages['success'] = 'Received!';
return $messages;
} );cf_form_default_settings
Filters the array of default settings for all forms. Extensions use this to register their own settings.
add_filter( 'cf_form_default_settings', function( $settings ) {
$settings['my_setting'] = 'default';
return $settings;
} );Form Processing Hooks
cf_process_form
Fires at the start of form processing, before validation results are checked.
add_action( 'cf_process_form', function( $form, $submission, $data, $error_code ) {
// Runs for every submission, even invalid ones
}, 10, 4 );cf_validate_form
Filters the validation error code. Return a non-empty string to reject the submission. The string is used as the message key.
add_filter( 'cf_validate_form', function( $error_code, $form, $data ) {
if ( $form->slug === 'application' && empty( $data['resume'] ) ) {
return 'required_field_missing';
}
return $error_code;
}, 10, 3 );cf_form_success
Fires after a successful submission, before form actions are processed.
add_action( 'cf_form_success', function( $submission, $form ) {
// Submission validated, about to run actions
}, 10, 2 );cf_submission_inserted
Fires after a submission is saved to the database.
add_action( 'cf_submission_inserted', function( $submission, $form ) {
// $submission->id is now available
}, 10, 2 );cf_form_response
Fires after form processing is complete, including when there are errors.
add_action( 'cf_form_response', function( $form, $submission, $error_code ) {
// Runs after every submission attempt
}, 10, 3 );cf_form_redirect_url
Filters the redirect URL after a successful submission.
add_filter( 'cf_form_redirect_url', function( $url, $form, $data ) {
return $url;
}, 10, 3 );cf_ignored_field_names
Filters the array of field names that should be excluded from submission data.
add_filter( 'cf_ignored_field_names', function( $names ) {
$names[] = 'tracking_pixel';
return $names;
} );cf_shortcode_form_identifier
Filters the form identifier (slug or ID) before the form is loaded.
add_filter( 'cf_shortcode_form_identifier', function( $identifier, $attributes ) {
return $identifier;
}, 10, 2 );Action Processing Hooks
cf_available_form_actions
Filters the array of available form action types. Each action class uses this to register itself.
add_filter( 'cf_available_form_actions', function( $actions ) {
$actions['my_action'] = 'My Custom Action';
return $actions;
} );cf_process_form_action_{type}
Fires when a specific action type needs to be processed.
add_action( 'cf_process_form_action_email', function( $settings, $submission, $form ) {
// Email action is being processed
}, 10, 3 );cf_output_form_action_{type}_settings
Fires when a specific action type’s settings should be rendered in the admin.
add_action( 'cf_output_form_action_webhook_settings', function( $settings, $index ) {
// Render webhook settings HTML
}, 10, 2 );Email Action Filters
cf_action_email_to
Filters the email recipient.
cf_action_email_subject
Filters the email subject.
cf_action_email_message
Filters the email message body.
cf_action_email_from
Filters the email sender address.
All email filters receive ($value, $submission) as parameters.
Auto-Responder Filters
cf_action_autoresponder_to
Filters the auto-responder recipient.
cf_action_autoresponder_subject
Filters the auto-responder subject.
cf_action_autoresponder_message
Filters the auto-responder message body.
cf_action_autoresponder_headers
Filters the auto-responder email headers array.
Webhook Hooks
cf_webhook_request_args
Filters the webhook request arguments before sending.
add_filter( 'cf_webhook_request_args', function( $args, $settings, $submission, $form ) {
return $args;
}, 10, 4 );cf_webhook_response
Fires after a webhook request completes.
add_action( 'cf_webhook_response', function( $response, $settings, $submission, $form ) {
// Check response status
}, 10, 4 );Template Tags
cf_template_tags
Filters the available template tag replacers for {{tag}} syntax.
add_filter( 'cf_template_tags', function( $tags ) {
$tags['custom'] = function( $param ) {
return "custom_$param";
};
return $tags;
} );Admin Hooks
cf_admin_action_{action}
Fires when a custom admin action is triggered.
cf_admin_output_form_tab_{tab}
Fires to render the content of a form editing tab.
cf_admin_output_form_messages
Fires to output additional message fields in the Messages tab.
cf_admin_output_form_settings
Fires to output additional settings in the form Settings tab.
cf_admin_output_settings
Fires to output additional fields on the global Settings page.
cf_admin_tabs
Filters the array of tabs shown when editing a form.
add_filter( 'cf_admin_tabs', function( $tabs, $form ) {
$tabs['analytics'] = 'Analytics';
return $tabs;
}, 10, 2 );cf_output_table_data_columns
Fires when rendering submission table columns.
Field Type Filter
cf_available_field_types
Filters the list of available field types in the form builder sidebar.
add_filter( 'cf_available_field_types', function( $types ) {
$types['color'] = array(
'text' => 'Color Picker',
'type' => 'input',
);
return $types;
} );Settings Filter
cf_settings
Filters the global plugin settings after they are loaded from the database.
add_filter( 'cf_settings', function( $settings ) {
return $settings;
} );Accessibility
cf_form_markup (priority 100)
The cf_enhance_accessibility function is hooked here to automatically add ARIA attributes, label associations, and other accessibility improvements to form markup.
Fullscreen Forms
cf_fullscreen_head
Fires in the <head> section of the fullscreen form page.
cf_fullscreen_footer
Fires before </body> in the fullscreen form page.
File Upload
cf_file_upload_use_direct_links
Filters whether file links in submissions should use direct URLs instead of WordPress attachment edit links.
add_filter( 'cf_file_upload_use_direct_links', '__return_true' );