Implemented: New feature to schedule cache flush by cron

Block/Adminhtml/Form/Renderer/Config/ScheduleEveryFieldComment.php

@@ -0,0 +1,38 @@
+<?php
+/**
+ * Copyright © Webscale. All rights reserved.
+ * See LICENSE for license details.
+ */
+
+namespace Webscale\Varnish\Block\Adminhtml\Form\Renderer\Config;
+
+use Magento\Framework\View\Element\AbstractBlock;
+use Magento\Config\Model\Config\CommentInterface;
+use Magento\Framework\View\Element\Context;
+use Webscale\Varnish\Helper\Config;
+
+class ScheduleEveryFieldComment extends AbstractBlock implements CommentInterface
+{
+    /**
+     * @param Context $context
+     * @param array $data
+     * @param Config $config
+     */
+    public function __construct(
+        Context $context,
+        Config $config
+    ) {
+        $this->config = $config;
+
+        parent::__construct($context);
+    }
+
+    /**
+     * @param $elementValue
+     * @return string
+     */
+    public function getCommentText($elementValue)
+    {
+        return 'Cron Expression: <span style="color:grey;">none</span>';
+    }
+}

Block/Adminhtml/Form/Renderer/Config/ScheduleEveryFieldConfig.php

@@ -0,0 +1,57 @@
+<?php
+/**
+ * Copyright © Webscale. All rights reserved.
+ * See LICENSE for license details.
+ */
+
+namespace Webscale\Varnish\Block\Adminhtml\Form\Renderer\Config;
+
+use Magento\Config\Block\System\Config\Form\Field;
+use Magento\Backend\Block\Template\Context;
+use Magento\Framework\Data\Form\Element\AbstractElement;
+use Magento\Framework\Data\Form\Element\Select;
+
+class ScheduleEveryFieldConfig extends Field
+{
+    public function __construct(
+        Context $context,
+        Select $select
+    ) {
+        $this->select = $select;
+
+        parent::__construct($context);
+    }
+
+    /**
+     * @param AbstractElement $element
+     * @return string
+     */
+    protected function _getElementHtml(AbstractElement $element) {
+        $name = $element->getName();
+
+        $element->setStyle('width: 100px; margin-right: 20px;')->setName($name . '[]');
+
+        if ($element->getValue()) {
+            $values = explode(',', $element->getValue());
+        } else {
+            $values = [];
+        }
+
+        $field = $element->setValue(isset($values[0]) ? $values[0] : null)->getElementHtml();
+
+        $units = $this->select->setName($name . '[]')
+            ->setStyle('width: 142px;')
+            ->setForm($element->getForm())
+            ->setValues([
+                ['value' => 'min', 'label' => 'minute(s)'],
+                ['value' => 'hour', 'label' => 'hour(s)']
+            ])
+            ->setId('webscale_varnish_flush_cache_schedule_time')
+            ->setValue(isset($values[1]) ? $values[1] : null)
+            ->getElementHtml();
+
+        return '<div style="float: left;">' . $field . '</div>'
+             . '<div style="float: left;">' . $units . '</div>'
+             . '<div style="clear: both"></div>';
+    }
+}

Block/System/Config/Scheduled.php

@@ -0,0 +1,39 @@
+<?php
+/**
+ * Copyright © Webscale. All rights reserved.
+ * See LICENSE for license details.
+ */
+
+namespace Webscale\Varnish\Block\System\Config;
+
+/**
+ * @SuppressWarnings(PHPMD.CamelCaseMethodName)
+ */
+class Scheduled extends \Webscale\Varnish\Block\System\Config\SettingsAbstract
+{
+    /**
+     * Return header comment part of html for fieldset
+     *
+     * @param \Magento\Framework\Data\Form\Element\AbstractElement $element
+     * @return string
+     * @SuppressWarnings(PHPMD.UnusedFormalParameter)
+     */
+    protected function _getHeaderCommentHtml($element): string
+    {
+        return $this->getCacheConfigMessage() . $this->getScheduledConfigMessage();
+    }
+
+    /**
+     * Check if account and application is configured
+     *
+     * @return string
+     */
+    private function getScheduledConfigMessage(): string
+    {
+        return $this->getMessageWrapper(
+            __('Enabling this feature will disable partial cache invalidation.' .
+                ' Full varnish cache flush will be executed instead, according to the cron expression configured below.'
+            ), 'warning'
+        );
+    }
+}

Block/System/Config/Settings.php

@@ -6,54 +6,17 @@
 
 namespace Webscale\Varnish\Block\System\Config;
 
-use Webscale\Varnish\Helper\Config;
-use Magento\Backend\Block\Context;
-use Magento\Backend\Model\Auth\Session;
-use Magento\Config\Block\System\Config\Form\Fieldset;
-use Magento\Framework\View\Helper\Js;
-use Magento\Backend\Model\UrlInterface;
 use Magento\PageCache\Model\Config as CacheConfig;
-use Magento\Framework\Data\Form\Element\AbstractElement;
 
 /**
  * @SuppressWarnings(PHPMD.CamelCaseMethodName)
  */
-class Settings extends Fieldset
+class Settings extends \Webscale\Varnish\Block\System\Config\SettingsAbstract
 {
-    /**
-     * @var Config $config
-     */
-    protected $config;
-
-    /**
-     * @param Context $context
-     * @param Session $authSession
-     * @param Js $jsHelper
-     * @param Config $config
-     * @param UrlInterface $urlBuilder
-     * @param CacheConfig $cacheConfig
-     * @param array $data
-     */
-    public function __construct(
-        Context $context,
-        Session $authSession,
-        Js $jsHelper,
-        Config $config,
-        UrlInterface $urlBuilder,
-        CacheConfig $cacheConfig,
-        array $data = []
-    ) {
-        $this->config = $config;
-        $this->urlBuilder = $urlBuilder;
-        $this->cacheConfig = $cacheConfig;
-
-        parent::__construct($context, $authSession, $jsHelper, $data);
-    }
-
     /**
      * Return header comment part of html for fieldset
      *
-     * @param AbstractElement $element
+     * @param \Magento\Framework\Data\Form\Element\AbstractElement $element
      * @return string
      * @SuppressWarnings(PHPMD.UnusedFormalParameter)
      */
@@ -105,22 +68,4 @@ private function getApplicationConfigMessage(): string
 
         return '';
     }
-
-    /**
-     * Get message wrapper
-     *
-     * @param string $message
-     * @param string $severity
-     * @return string
-     */
-    private function getMessageWrapper(string $message = '', string $severity = 'notice'): string
-    {
-        $html  = '<div style="padding:10px;"><div class="messages">';
-        $html .= '<div class="message message-' . $severity . ' ' . $severity . '" style="margin-bottom: 0;">';
-        $html .= '<div data-ui-id="messages-message-' . $severity . '">';
-        $html .= $message;
-        $html .= '</div></div></div></div>';
-
-        return $html;
-    }
 }

Block/System/Config/SettingsAbstract.php

@@ -0,0 +1,66 @@
+<?php
+/**
+ * Copyright © Webscale. All rights reserved.
+ * See LICENSE for license details.
+ */
+
+namespace Webscale\Varnish\Block\System\Config;
+
+use Magento\Backend\Block\Context;
+use Magento\Backend\Model\Auth\Session;
+use Magento\Backend\Model\UrlInterface;
+use Magento\Config\Block\System\Config\Form\Fieldset;
+use Magento\Framework\View\Helper\Js;
+use Magento\PageCache\Model\Config as CacheConfig;
+use Webscale\Varnish\Helper\Config;
+
+abstract class SettingsAbstract extends Fieldset
+{
+    /**
+     * @var Config $config
+     */
+    protected $config;
+
+    /**
+     * @param Context $context
+     * @param Session $authSession
+     * @param Js $jsHelper
+     * @param Config $config
+     * @param UrlInterface $urlBuilder
+     * @param CacheConfig $cacheConfig
+     * @param array $data
+     */
+    public function __construct(
+        Context      $context,
+        Session      $authSession,
+        Js           $jsHelper,
+        Config       $config,
+        UrlInterface $urlBuilder,
+        CacheConfig  $cacheConfig
+    )
+    {
+        $this->config = $config;
+        $this->urlBuilder = $urlBuilder;
+        $this->cacheConfig = $cacheConfig;
+
+        parent::__construct($context, $authSession, $jsHelper);
+    }
+
+    /**
+     * Get message wrapper
+     *
+     * @param string $message
+     * @param string $severity
+     * @return string
+     */
+    public function getMessageWrapper(string $message = '', string $severity = 'notice'): string
+    {
+        $html  = '<div style="padding:10px;"><div class="messages">';
+        $html .= '<div class="message message-' . $severity . ' ' . $severity . '" style="margin-bottom: 0;">';
+        $html .= '<div data-ui-id="messages-message-' . $severity . '">';
+        $html .= $message;
+        $html .= '</div></div></div></div>';
+
+        return $html;
+    }
+}

Cron/CacheFlushScheduled.php

@@ -0,0 +1,58 @@
+<?php
+/**
+ * Copyright © Webscale. All rights reserved.
+ * See LICENSE for license details.
+ */
+
+namespace Webscale\Varnish\Cron;
+
+use Webscale\Varnish\Helper\Config;
+use Magento\PageCache\Model\Config as CacheConfig;
+use Webscale\Varnish\Model\PurgeCache;
+
+class CacheFlushScheduled
+{
+    const EVENT_NAME = 'webscale_varnish_flush_all_scheduled';
+
+    /** @var Config $config */
+    private $config;
+
+    /** @var CacheConfig $cacheConfig */
+    private $cacheConfig;
+
+    /** @var PurgeCache $purgeCache */
+    private $purgeCache;
+
+    /**
+     * @param Config $config
+     */
+    public function __construct(
+        CacheConfig $cacheConfig,
+        Config $config,
+        PurgeCache $purgeCache
+    ) {
+        $this->config = $config;
+        $this->cacheConfig = $cacheConfig;
+        $this->purgeCache = $purgeCache;
+    }
+
+    /**
+     * @return void
+     */
+    public function execute() {
+        try {
+            if (
+                $this->cacheConfig->getType() == CacheConfig::VARNISH
+                && $this->config->isAvailable()
+                && !empty($this->config->getCronExpression())
+            ) {
+                $this->purgeCache->sendPurgeRequest(['tagsPattern' => ['.*'], 'event' => self::EVENT_NAME]);
+                $this->config->log('Executed scheduled varnish cache flush.');
+            }
+        } catch (\Exception $e) {
+            $this->config->log('Unable to execute scheduled varnish cache flush.');
+            $this->config->log($e->getMessage() . PHP_EOL . $e->getTraceAsString(), 'critical');
+        }
+
+    }
+}