Joomla 3 - How to call a function on Module save?

Question

I have a module, and a number of different fields for authentication with an API.

I want to perform the API authentication when the Save button is clicked, and return a success or fail message depending on the authentication?

How can I achieve this in Joomla?

Answer 1

Create a plugin with onExtensionBeforeSave and/or onExtensionAfterSave event.

public function onExtensionBeforeSave($context, $item, $isNew)
{
    // Check that we are editing our module.
    if ($context !== 'com_modules.module' || $item->module !== 'mod_example')
    {
        return true;
    }

    // Do stuff here.
    $params = new JRegistry($item->params);

    // Our stuff fails, don't save the module.
    if (!$this->doStuff($params))
    {
        return false;
    }

    return true;
}

Alternative way, which may or may not be suitable in your case, is to create a form validation rule in your module. This would not require a plugin. See documentation https://docs.joomla.org/Server-side_form_validation.