custom-placeholders.md

Custom Placeholders

This is the only way to add links or other dynamic content to the log entry. The example below will replace {banner} with a link to a banner edit page. We prefer to use a placeholder so the message can be translated later. It also offers the benefit of being able to load the current banner (using the id context) which allows the link to always use the most up to date name, or no link can be returned if the banner no longer exists.

See Placeholder/Handler/*Handler.php for more examples.

Create handler class

The handler class must implement HandlerInterface.

<?php

namespace ExampleCompany\ExamplePlugin\EventLog\Placeholder;

// ...

use Ryvon\EventLog\Placeholder\Handler\LinkPlaceholderTrait;
use Ryvon\EventLog\Placeholder\Handler\HandlerInterface;

class BannerHandler implements HandlerInterface
{
    use LinkPlaceholderTrait;

    // ...

    /**
     * @inheritDoc
     */
    public function handle(\Magento\Framework\DataObject $context)
    {
        $bannerId = $context->getData('id');
        $bannerName = $context->getData('text');

        // When invalid context is found we return null which tells the placeholder to
        // use (and escape) the text context.
        if (!$bannerId || !$bannerName) {
            return null;
        }

        // Ensure the banner still exists to link to.
        $banner = $this->findBannerById($bannerId);
        if (!$banner) {
            return null;
        }

        // Return a link to the banner.
        return $this->buildLinkTag([
            'text' => $banner->getName(),
            'title' => 'Edit this banner in the admin',
            'href' => $this->urlBuilder->getUrl('banners/banner/edit', [
                'banner_id' => $bannerId,
            ]),
            'target' => '_blank',
        ]);
    }
}

Add handler to the replacer

In your plugin's di.xml add the handler to the PlaceholderProcessor constructor.

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">

    <!-- ... -->

    <!-- Add the handler to the placeholder processor -->
    <type name="Ryvon\EventLog\Placeholder\PlaceholderProcessor">
        <arguments>
            <argument name="handlers" xsi:type="array">
                <!-- The name attribute should be set to the search string (the text between the curly-brackets). -->
                <item name="banner" xsi:type="object">
                    ExampleCompany\ExamplePlugin\EventLog\Placeholder\BannerHandler
                </item>
            </argument>
        </arguments>
    </type>
</config>