Feature: #66369 - Added LinkBrowser APIs

See Issue #66369

Description

This new feature allows to extend the link browser with new tabs, which allow to implement custom link functionality in a generic way in a so called LinkHandler. Since the LinkBrowser is used by FormEngine and RTE, the new API ensures that your custom LinkHandler works with those two, and possible future, usages flawlessly.

Each tab rendered in the link browser has an associated link handler, responsible for rendering the tab and for creating and editing of links belonging to this tab.

Tab registration

Link browser tabs are registered in page TSconfig like this:

TCEMAIN.linkHandler.<tabIdentifier> {
        handler = TYPO3\CMS\Recordlist\LinkHandler\FileLinkHandler
        label = LLL:EXT:lang/locallang_browse_links.xlf:file
        displayAfter = page
        scanAfter = page
        configuration {
                customConfig = passed to the handler
        }
}

The options displayBefore and displayAfter define the order how the various tabs are displayed in the link browser.

The options scanBefore and scanAfter define the order in which handlers are queried when determining the responsible tab for an existing link. Most likely your links will start with a specific prefix to identify them. Therefore you should register your tab at least before the 'url' handler, so your handler can advertise itself as responsible for the given link. The 'url' handler should be treated as last resort as it will work with any link.

Handler implementation

A link handler has to implement the \TYPO3\CMS\Recordlist\LinkHandler\LinkHandlerInterface interface, which defines all necessary methods for communication with the link browser.

Additionally, each link handler should also provide a Javascript module (requireJS), which takes care of passing a link to the link browser. A minimal implementation of such a module looks like this:

define(['jquery', 'TYPO3/CMS/Recordlist/LinkBrowser'], function($, LinkBrowser) {

        var myModule = {};

        myModule.createMyLink = function() {
                var val = $('.myElmeent').val();

                // optional: If your link points to some external resource you should set this attribute
                LinkBrowser.setAdditionalLinkAttribute('data-htmlarea-external', '1');

                LinkBrowser.finalizeFunction('mylink:' + val);
        };

        myModule.initialize = function() {
                // todo add necessary event handlers, which will propably call myModule.createMyLink
        };

        $(myModule.initialize);

        return myModule;
}

Notice the call to LinkBrowser.finalizeFunction, which is the point where the link is handed over to the link browser for further processing and storage.

Hooks

You may have the need to modify the list of available link handlers based on some dynamic value. For this purpose you can register hooks.

The registration of a link browser hook generally happens in your ext_tables.php and looks like:

if (TYPO3_MODE === 'BE') {
        $GLOBALS['TYPO3_CONF_VARS']['SC_OPTIONS']['LinkBrowser']['hooks'][1444048118] = [
                'handler' => \Vendor\Ext\MyClass::class,
                'before' => [], // optional
                'after' => [] // optional
        ];
}

The before and after elements allow to control the execution order of all registered hooks.

Currently the following list of hooks is implemented:

  • modifyLinkHandlers(linkHandlers, currentLinkParts): May modify the list of available link handlers and has to return the final list.
  • modifyAllowedItems(allowedTabs, currentLinkParts): May modify the list of available tabs and has to return the final list.