Add optional polling behaviour

Author: jissereitsma

Config/Config.php

@@ -13,6 +13,14 @@ public function __construct(
     ) {
     }
 
+    public function getPollingInterval(): int
+    {
+        return (int)$this->scopeConfig->getValue(
+            'loki_components/general/polling_interval',
+            ScopeInterface::SCOPE_STORE
+        );
+    }
+
     public function isDebug(): bool
     {
         return (bool)$this->scopeConfig->getValue(

Controller/Index/Polling.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Loki\Components\Controller\Index;
+
+use Loki\Components\Polling\PollingHandlerListing;
+use Magento\Framework\App\Action\HttpGetActionInterface;
+use Magento\Framework\App\ResponseInterface;
+use Magento\Framework\Controller\Result\JsonFactory as JsonResultFactory;
+use Magento\Framework\Controller\ResultInterface;
+
+class Polling implements HttpGetActionInterface
+{
+    public function __construct(
+        private readonly JsonResultFactory $jsonResultFactory,
+        private readonly PollingHandlerListing $pollingHandlerListing,
+    ) {
+    }
+
+    public function execute(): ResultInterface|ResponseInterface
+    {
+        $data = [];
+        foreach ($this->pollingHandlerListing->getHandlers() as $handler) {
+            $data = array_merge($data, $handler->execute());
+        }
+
+        $jsonResult = $this->jsonResultFactory->create();
+        $jsonResult->setData($data);
+        return $jsonResult;
+    }
+}

Polling/AbstractPollingHandler.php

@@ -0,0 +1,14 @@
+<?php
+declare(strict_types=1);
+
+namespace Loki\Components\Polling;
+
+abstract class AbstractPollingHandler implements PollingHandlerInterface
+{
+    abstract public function execute(): array;
+
+    public function getMessageData(string $messageType, string $message): array
+    {
+        return ['messageType' => $messageType, 'message' => $message];
+    }
+}

Polling/PollingHandlerInterface.php

@@ -0,0 +1,9 @@
+<?php
+declare(strict_types=1);
+
+namespace Loki\Components\Polling;
+
+interface PollingHandlerInterface
+{
+    public function execute(): array;
+}

Polling/PollingHandlerListing.php

@@ -0,0 +1,20 @@
+<?php
+declare(strict_types=1);
+
+namespace Loki\Components\Polling;
+
+class PollingHandlerListing
+{
+    public function __construct(
+        private readonly array $handlers,
+    ) {
+    }
+
+    /**
+     * @return PollingHandlerInterface[]
+     */
+    public function getHandlers(): array
+    {
+        return $this->handlers;
+    }
+}

Util/ComponentUtil.php

@@ -63,6 +63,11 @@ public function getPostUrl(): string
         return $this->urlFactory->create()->getUrl('loki_components/index/html');
     }
 
+    public function getPollingUrl(): string
+    {
+        return $this->urlFactory->create()->getUrl('loki_components/index/polling');
+    }
+
     public function getFormHtml(AbstractBlock $block): string
     {
         /** @var AbstractBlock $formBlock */

etc/adminhtml/system.xml

@@ -22,6 +22,17 @@
                     <tooltip>When debugging is enabled, on various levels, detailed information comes available. For instance, in the browser Error Console, more debugging messages are displayed, allowing you to inspect issues on the JavaScript level. Whenever an exception occurs within the AJAX call, the exception message is appended to the AJAX output.</tooltip>
                     <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
                 </field>
+                <field id="polling_interval"
+                       translate="label"
+                       type="text"
+                       sortOrder="1"
+                       showInDefault="1"
+                       showInWebsite="1"
+                       showInStore="0">
+                    <label>Polling Interval</label>
+                    <tooltip>If you have added polling handlers, set this to an interval with which you want those polling handlers to act.</tooltip>
+                    <source_model>Magento\Config\Model\Config\Source\Yesno</source_model>
+                </field>
             </group>
         </section>
     </system>

view/base/layout/loki_components.xml

@@ -13,6 +13,10 @@
         </block>
 
         <referenceBlock name="loki.script">
+            <block
+                name="loki-components.script.polling"
+                template="Loki_Components::script/polling.phtml"/>
+
             <block
                 name="loki-components.script.logger"
                 template="Loki_Components::script/logger.phtml"/>

view/base/templates/script/polling.phtml

@@ -0,0 +1,71 @@
+<?php declare(strict_types=1);
+
+use Loki\Components\Util\ComponentUtil;
+use Magento\Framework\Escaper;
+use Magento\Framework\View\Element\Template;
+use Loki\Components\Config\Config;
+use Loki\Components\Factory\ViewModelFactory;
+
+/** @var Template $block */
+/** @var ViewModelFactory $viewModelFactory */
+/** @var Config $config */
+/** @var Config $componentUtil */
+/** @var ComponentUtil $componentUtil */
+/** @var Escaper $escaper */
+
+$config = $viewModelFactory->create(Config::class);
+$componentUtil = $viewModelFactory->create(ComponentUtil::class);
+$interval = $this->getPollingInterval();
+if ($interval < 500) {
+    return;
+}
+?>
+<script>
+    (() => {
+        setInterval(() => {
+            fetch('<?= $escaper->escapeUrl($componentUtil->getPollingUrl()) ?>?form_key=' + LokiComponentFormKey + '&isAjax=true', {
+                method: 'GET',
+                headers: {
+                    'X-Requested-With': 'XMLHttpRequest',
+                    'Content-Type': 'application/json'
+                },
+            })
+                .then(response => {
+                    if (response.ok) {
+                        return response.text()
+                    }
+
+                    LokiComponentsLogger.error('Fetch error', response);
+                    throw new Error(response.statusText);
+                })
+                .then(html => {
+                    try {
+                        const data = JSON.parse(html);
+                        if (data) {
+                            data.forEach(dataPart => {
+                                if (dataPart.message) {
+                                    const messageType = dataPart.messageType ?? 'notice';
+                                    Alpine.store('Message').addMessage(messageType, dataPart.message);
+                                }
+
+                                if (dataPart.redirectUrl) {
+                                    if (dataPart.redirectMessage) {
+                                        Alpine.store('Message').addWarningMessage(dataPart.redirectMessage);
+                                    }
+
+                                    const seconds = 3;
+                                    setTimeout(() => {
+                                        window.location = dataPart.redirectUrl;
+                                    }, seconds * 1000)
+                                }
+                            });
+                        }
+                    } catch (e) {
+                    }
+                })
+                .catch(error => {
+                    Alpine.store('Message').addErrorMessage(error);
+                });
+        }, <?= $interval ?>);
+    })();
+</script>