Overriding Form Fields.

It's possible to completely override a form field by passing a directory to the siteorigin_widgets_field_registered_class_paths filter that contains a file named exactly the same as the base form field with the same class set. For example, if I wanted to override the TinyMCE field I would load a directory containing fields using the following PHP:

function siteorigin_load_custom_form_fields( $class_paths ) {
    array_unshift( $class_paths['base'], plugin_dir_path( __FILE__ ) . 'fields/' );
    return $class_paths;
}
add_filter( 'siteorigin_widgets_field_registered_class_paths', 'siteorigin_load_custom_form_fields' );

The above snippet will only work in a plugin without modification.

Then create a directory in the same directory as the above PHP snippet called fields. In that directory please add a file called tinymce.class.php (the same filename as the base TinyMCE Form Field). Add the following PHP to that file:

<?php
class SiteOrigin_Widget_Field_TinyMCE extends SiteOrigin_Widget_Field_Text_Input_Base {
    protected function render_field( $value, $instance ) {
        echo 'Field was successfully replaced.';
    }
}

This will now override the TinyMCE field with the message 'Field was successfully replaced'.

Here's a reference plugin containing the above code with the outlined file structure