init.php

<?php

namespace Initbiz\LeafletPro;

use Event;
use System\Classes\PluginManager;
use RainLab\Location\Models\Country;
use Initbiz\LeafletPro\Models\Marker;

if (PluginManager::instance()->exists('Initbiz.CumulusCore')) {
    Event::listen('backend.form.extendFieldsBefore', function ($formWidget) {
        if (!$formWidget->model instanceof Marker) {
            return;
        }

        $clusterField = [];
        $clusterField['cluster_id'] = [
            'label' => 'initbiz.leafletpro::lang.marker.cluster',
            'commentAbove' => 'initbiz.leafletpro::lang.marker.cluster_comment',
            'type' => 'dropdown',
            'span' => 'full',
            'emptyOption' => 'initbiz.leafletpro::lang.marker.cluster_empty_option',
            'tab' => 'initbiz.leafletpro::lang.marker.address_tab',
        ];

        $fields = $formWidget->tabs['fields'];

        $fields['street']['dependsOn'] = 'cluster_id';
        $fields['postal_code']['dependsOn'] = 'cluster_id';
        $fields['city']['dependsOn'] = 'cluster_id';
        $fields['country_id']['dependsOn'] = 'cluster_id';

        $formWidget->tabs['fields'] = $clusterField + $fields;
    });

    Marker::extend(function ($model) {
        $model->belongsTo['cluster'] = ['Initbiz\CumulusCore\Models\Cluster'];

        $model->addDynamicMethod('getClusterIdOptions', function () {
            return \Initbiz\CumulusCore\Models\Cluster::all()->pluck('name', 'id')->toArray();
        });
    });

    \Initbiz\CumulusCore\Models\Cluster::extend(function ($model) {
        $model->hasMany['markers'] = ['Initbiz\LeafletPro\Models\Marker'];

        $model->bindEvent('model.afterSave', function () use ($model) {
            if ($model->markers()->count() === 0) {
                // If cluster has no marker, create one
                if (!empty($model->city) && !empty($model->thoroughfare) && !empty($model->name)) {
                    $marker = new Marker();
                    $marker->name = $model->name;
                    $marker->cluster_id = $model->id;
                    $marker->street = $model->thoroughfare;
                    $marker->city = $model->city;
                    if (!empty($marker->country_id)) {
                        $country = Country::find($marker->country_id);
                        $marker->country()->associate($country);
                    }
                    if (!empty($marker->postal_code)) {
                        $marker->postal_code = $model->postal_code;
                    }

                    try {
                        $marker->refreshLatLon();
                        $marker->save();
                    } catch (\Exception $e) {
                        $message = [
                            'message'   => 'Tried to refresh the marker',
                            'marker'    => $marker->toArray(),
                            'exception' => $e->getMessage(),
                        ];

                        trace_log($message);
                    }
                }
            } else {
                // else get first and if address updated than update marker
                if (!empty($model->city) && !empty($model->thoroughfare) && !empty($model->name)) {
                    $marker = $model->markers()->first();

                    $markerChanged = false;

                    if ($marker->city !== $model->city) {
                        $marker->city = $model->city;
                        $markerChanged = true;
                    }

                    if ($marker->street !== $model->thoroughfare) {
                        $marker->street = $model->thoroughfare;
                        $markerChanged = true;
                    }

                    if ($marker->country_id !== $model->country_id) {
                        $marker->country_id = $model->country_id;
                        $markerChanged = true;
                    }

                    if ($marker->postal_code !== $model->postal_code) {
                        $marker->postal_code = $model->postal_code;
                        $markerChanged = true;
                    }

                    if ($markerChanged) {
                        try {
                            $marker->refreshLatLon();
                            $marker->save();
                        } catch (\Exception $e) {
                            $message = [
                                'message'   => 'Tried to refresh the marker',
                                'marker'    => $marker->toArray(),
                                'exception' => $e->getMessage(),
                            ];

                            trace_log($message);
                        }
                    }
                }
            }
        }, 50);
    });

    \Initbiz\CumulusCore\Controllers\Clusters::extendFormFields(function ($form, $model, $context) {
        if (!$model instanceof \Initbiz\CumulusCore\Models\Cluster) {
            return;
        }
        //TODO: add relation controller for managing map markers
    });
}