SugarCRM - Add item to action menu on Record View

CustomMODULE_NAMEApi.php

<?php

if(!defined('sugarEntry') || !sugarEntry) die('Not A Valid Entry Point');

class CustomMODULE_NAMEApi extends SugarApi
{
    public function registerApiRest() {
        return array(
            'CasesLinkedTestsEndpoint' => array(
                'reqType' => 'POST',
                'path' => array('MODULE_NAME','?', 'do-custom-stuff'),
                'pathVars' => array('module', 'record'),
                'method' => 'doCustomStuff',
                'shortHelp' => 'Do some custom backend stuff intiated from action menu on frontend',
                'longHelp' => '',
            ),
        );
    }

    public function doCustomStuff($api, $args) {
        $record_id = $args['record'];
        // do some stuff
        
        // api handles json_encoding, just return the object
        return $results;
    }
}

record.js

({
    extendsFrom: 'RecordView',
    // if you are extending the record view for a core module that has an existing record.js you must extend that view
    // extendsFrom: 'ContactsRecordView',

    initialize: function(options) {
        this._super('initialize', [options]);

        // generate client pdfs
        this.context.on('button:do_custom_stuff:click', this.do_custom_stuff, this);
    },
    
    do_custom_stuff: function() {
        var extra_info_obj = {
            prop_1: 'some info',
            prop_2: 'some more info',
        }
        
        app.api.call('create', app.api.buildURL('MODULE_NAME/'+this.model.id+'/do-custom-stuff'),
        {
            extra_info: extra_info_obj,
        },
        {
            success: function(data) {
                console.log(data);
            }
        });
    },
})

record.php

<?php

// this is the file located in custom/modules/MODULE_NAME/clients/base/views/record/

$viewdefs['MODULE_NAME'] = 
array (
  'base' => 
  array (
    'view' => 
    array (
      'record' => 
      array (
        'buttons' => 
        array (
          0 => 
          array (
            'type' => 'button',
            'name' => 'cancel_button',
            'label' => 'LBL_CANCEL_BUTTON_LABEL',
            'css_class' => 'btn-invisible btn-link',
            'showOn' => 'edit',
          ),
          1 => 
          array (
            'type' => 'rowaction',
            'event' => 'button:save_button:click',
            'name' => 'save_button',
            'label' => 'LBL_SAVE_BUTTON_LABEL',
            'css_class' => 'btn btn-primary',
            'showOn' => 'edit',
            'acl_action' => 'edit',
          ),
          2 => 
          array (
            'type' => 'actiondropdown',
            'name' => 'main_dropdown',
            'primary' => true,
            'showOn' => 'view',
            'buttons' => 
            array (
              0 => 
              array (
                'type' => 'rowaction',
                'event' => 'button:edit_button:click',
                'name' => 'edit_button',
                'label' => 'LBL_EDIT_BUTTON_LABEL',
                'primary' => true,
                'acl_action' => 'edit',
              ),
              // THIS IS THE CUSTOM ACTION ITEM
              1 => // you can get rid of all the numeric indexes to avoid re-typing them if you want
              array (
                'type' => 'rowaction',
                'event' => 'button:do_custom_stuff:click', // method name to call in record.js
                'name' => 'do_custom_stuff', // name attribute of your button
                'label' => 'Do Custom Stuff',
                'acl_action' => 'edit',
              ),
              // END CUSTOM ACTION ITEM
              // REMOVED all the other junk in this file, you should keep it :-)
              ),
            ),
          ),
        ),
      ),
    ),
  );