ModifyPluginViewEvent 

\FGTCLB\AcademicBase\Event\ModifyPluginViewEvent belongs to academic_base, and the plugins of seven academic extensions dispatch it. It hands a listener the view of a plugin once the plugin has assigned its own variables, so a listener adds a variable to the templates without replacing the controller. The event itself, and the rules that apply to every plugin, are described on its page in the manual of academic_base. This page describes what the content element of academic_contacts4pages passes in.

When it is dispatched 

ContactsController::listAction() dispatches it once each time the content element Person’s Contacts on the Page renders, as the last step of the action, after ModifyPageContactsEvent and after the view variables are assigned. The data processor for page templates renders no plugin and does not dispatch it.

What this extension passes in 

Method Returns
getPluginControllerActionContext() The context of the content element: the extension name AcademicContacts4pages , the plugin name List , the action name list , the request, the site and its language, the content object, and the settings of the content element, its FlexForm merged over plugin.tx_academiccontacts4pages.settings .
getView() The view, with {contacts} , {roles} , {contactsWithoutRole} , {data} and {record} assigned.

Example 

A site shows a link to its contact form below the contacts of every page. The uid of the page with the form is a site setting of the site package, and a listener hands it to the template of the content element:

EXT:my_extension/Classes/EventListener/AddContactFormPageToThePageContacts.php 
<?php

declare(strict_types=1);

namespace MyVendor\MyExtension\EventListener;

use FGTCLB\AcademicBase\Event\ModifyPluginViewEvent;
use TYPO3\CMS\Core\Attribute\AsEventListener;

final class AddContactFormPageToThePageContacts
{
    #[AsEventListener(identifier: 'my-extension/add-contact-form-page-to-the-page-contacts')]
    public function __invoke(ModifyPluginViewEvent $event): void
    {
        $context = $event->getPluginControllerActionContext();
        if ($context->getControllerExtensionName() !== 'AcademicContacts4pages'
            || $context->getPluginName() !== 'List'
        ) {
            return;
        }
        $pageUid = (int)($context->getSite()?->getSettings()->get('myExtension.contactFormPage') ?? 0);
        if ($pageUid > 0) {
            $event->getView()->assign('contactFormPage', $pageUid);
        }
    }
}
Copied!

An override of Templates/Contacts/List.html renders the link with <f:link.page pageUid="{contactFormPage}"> .

Rules and pitfalls 

Check the extension name as well as the plugin name. List is the plugin name of plugins of other academic extensions too.

A replaced variable is replaced in the view only. Which contacts a page shows belongs in ModifyPageContactsEvent, which reaches the data processor as well, and which keeps the roles and the contacts without role in line with the contacts.

The content element is cached. It is rendered when the page is rendered, and the page is cached with what the listener assigned, so a listener cannot assign something different for different visitors.

Introduced in