[concrete5][V8][MigrationTool] Example of creating custom publisher

app.php

<?php
Events::addListener('on_before_dispatch', function($event) {
    /** @var \PortlandLabs\Concrete5\MigrationTool\Publisher\Block\Manager $blockPublisherManager */
    $blockPublisherManager = Core::make('migration/manager/publisher/block');
    if (is_object($blockPublisherManager)) {
        $originalBlockTypeHandle = 'manual_nav';
        $blockPublisherManager->extend($originalBlockTypeHandle, function () {
            return new \Application\Concrete\MigrationTool\Publisher\Block\ManualNavPublisher();
        });
    }
});

ManualNavPublisher.php

<?php
// application/src/Concrete/MigrationTool/Publisher/Block/ManualNavPublisher.php

namespace Application\Concrete\MigrationTool\Publisher\Block;

use Concrete\Core\Block\Block;
use Concrete\Core\Page\Page;
use PortlandLabs\Concrete5\MigrationTool\Entity\Import\Batch;
use PortlandLabs\Concrete5\MigrationTool\Entity\Import\BlockValue\BlockValue;
use PortlandLabs\Concrete5\MigrationTool\Publisher\Block\PublisherInterface;

class ManualNavPublisher implements PublisherInterface
{
    public function publish(Batch $batch, $bt, Page $page, $area, BlockValue $value)
    {
        $records = $value->getRecords();
        $inspector = \Core::make('migration/import/value_inspector', array($batch));
        foreach ($records as $record) {
            if (strcasecmp($record->getTable(), $bt->getController()->getBlockTypeDatabaseTable()) == 0) {
                /** @var Block $b */
                $b = $page->addBlock($bt, $area, []);
            }
        }
        // Now we import the OTHER records.
        if ($b) {
            $data = [];
            $i = 0;
            foreach ($records as $record) {
                if (strcasecmp($record->getTable(), $bt->getController()->getBlockTypeDatabaseTable()) != 0) {
                    $data['linkType'][$i] = 1;
                    $data['linkURL'][$i] = '';
                    foreach ($record->getData() as $key => $value) {
                        $result = $inspector->inspect($value);
                        if ($key == 'linkToCID') {
                            $data['internalLinkCID'][$i] = $result->getReplacedValue();
                        }
                        if ($key == 'linkText') {
                            $data['title'][$i] = $result->getReplacedValue();
                        }
                        if ($key == 'position') {
                            $data['sortOrder'][$i] = $result->getReplacedValue();
                        }
                    }
                    $i++;
                }
            }
            $b->update($data);
            return $b;
        }
    }
}