By default, ACF values functions are wrapped within the form context. This allows to use functions such as get_field(), get_fields(), have_rows(), get_sub_field() without any $post_id to retrieve the field input values.

add_action('acfe/form/submit_form/form=my-form', 'my_form_submission');
function my_form_submission($form){

    $inputs = get_fields();             // all inputs values
    $inputs = get_fields(false, false); // all inputs values (unformatted)

    $my_field = get_field('my_field');               // input value
    $my_field = get_field('my_field', false, false); // input value (unformatted)
    
    if(have_rows('my_repeater')):
        while(have_rows('my_repeater')): the_row();

            $sub_field = get_sub_field('sub_field');        // subfield input value
            $sub_field = get_sub_field('sub_field', false); // subfield input value (unformatted)

        endwhile;
    endif;

}

#Get DB Field Value

To retrieve values from the database, you’ll have to pass the corresponding $post_id. Usage example:

add_action('acfe/form/submit_form/form=my-form', 'my_form_submission');
function my_form_submission($form){

    $inputs = get_fields(45);        // all db values
    $inputs = get_fields(45, false); // all db values (unformatted)

    $my_field = get_field('my_field', 45);        // db value
    $my_field = get_field('my_field', 45, false); // db value (unformatted)

    // repeater
    if(have_rows('my_repeater', 45)):
        while(have_rows('my_repeater', 45)): the_row();

            $sub_field = get_sub_field('sub_field');        // subfield db value
            $sub_field = get_sub_field('sub_field', false); // subfield db value (unformatted)

        endwhile;
    endif;

}

#Get Action Output

The acfe_get_form_action() function can be used to retrieve a previous action output. This function is useful to get a previous action data.

/**
 * Get Action Output
 * 
 * @param   string  $path     Action name. Allows dot notation to get sub value
 * @param   string  $default  The default returned value, if none was found
 * @return  mixed
 */
acfe_get_form_action($path = '', [$default = null])

/**
 * Get All Actions Output
 * 
 * @return  array
 */
acfe_get_form_actions()

Considering the following form configuration, which create a page and then send an email:

acfe_form(array(
    'name' => 'my-form',
    'field_groups' => array(
        'group_5ffd27b7d0c62',
    ),
    'actions' => array(

        // create post
        array(
            'action' => 'post',
            'name'   => 'my-post',
            'type'   => 'insert_post',
            'save'   => array(
                'post_type'    => 'page',
                'post_status'  => 'publish',
                'post_title'   => '{field:field_5ff7ee7cdd8f3}',
            ),
        ),

        // send email
        array(
            'action' => 'email',
            'name'   => 'my-email',
            'email' => array(
                'from' => '[email protected]',
                'to'   => '[email protected]',
                'subject' => 'Subject',
                'content' => '{fields}',
            ),
        ),

    ),
));

We can hook in the Email filter acfe/form/submit_email_args in order to retreive the previous Post Action output, and use the “Post Title” as “Subject”. Usage example:

add_filter('acfe/form/submit_email_args/form=my-form', 'my_email_args', 10, 3);
function my_email_args($args, $form, $action){
    
    // get the whole post output
    $post = acfe_get_form_action('post');
    /**
     * $post = array(
     *     'ID' => 1554,
     *     'post_author' => 1,
     *     'post_date' => '2020-08-19 20:53:31',
     *     'post_date_gmt' => '0000-00-00 00:00:00',
     *     'post_content' => '',
     *     'post_title' => 'My Post',
     *     ...
     * )
     */

    // assign subject
    // use previous post action 'post_title' output
    $args['subject'] = acfe_get_form_action('post.post_title');

    // return
    return $args;

}

Since the Post Action is named my-post, we can also specifically target this action using acfe_get_form_action('my-post.post_title').

#Form Success

The acfe_is_form_success() can be used to check if the current page is a Form Success Page. This helper can be useful to display a custom success message . Usage example:

/*
 * Is Form Success
 * 
 * @param   string  $form  Form name or form array
 * @return  bool
 */
acfe_is_form_success([$form = ''])

// success Message
if(acfe_is_form_success('my-form')){

    echo '<h3>Thank you</h3>';
    echo '<p>The form has been successfully submitted.</p>';
    
    // retrieve the ID of the created/updated post in a Post Action
    $post_id = acfe_get_form_action('post.ID');

    // retrieve the title and permalink
    $title = get_the_title($post_id);
    $permalink = get_permalink($post_id);

    // print message
    echo '<p><a href="' . $permalink . '">' . $title . '</a> has been created</p>';
    
// render Form
}else{

    acfe_form(array(
        'name' => 'my-form'
    ));

}

Using that helper, we can setup multiple forms acting like steps on the same page. Usage example:

// no form was submitted
if(!acfe_is_form_success()){

    // display form-1
    acfe_form(array(
        'name' => 'my-form-1'
    ));
    
// form-1 was submitted
}elseif(acfe_is_form_success('my-form-1')){

    // display form-2
    acfe_form(array(
        'name' => 'my-form-2'
    ));

// form-2 was submitted
}elseif(acfe_is_form_success('my-form-2')){

    // display form-3
    acfe_form(array(
        'name' => 'my-form-3'
    ));

}

#Import Json Form

It is possible to import exported Json form using the acfe_import_form() function. Usage example:

add_action('admin_init', 'my_acf_import_form');
function my_acf_import_form(){
    
    // retrieve json file
    $file = get_stylesheet_directory() . '/acfe-form-export.json';
    $content = file_get_contents($file);
    
    // import form
    acfe_import_form($content);
    
}

You only need to run that hook one time, so once the form is imported you can remove that code.