CSS inliner plugin

app/Providers/MailCssInlinerServiceProvider.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace App\Providers;
+
+use App\Utils\CssInlinerPlugin;
+use Illuminate\Mail\MailManager;
+use Illuminate\Support\ServiceProvider;
+
+class MailCssInlinerServiceProvider extends ServiceProvider
+{
+    // Thanks to @fedeisas/laravel-mail-css-inliner
+
+    /**
+     * Bootstrap the application events.
+     *
+     * @return void
+     */
+    public function boot()
+    {
+        $this->publishes([
+            __DIR__ . '/../config/css-inliner.php' => base_path('config/css-inliner.php'),
+        ], 'config');
+    }
+
+    /**
+     * Register the service provider.
+     *
+     * @return void
+     */
+    public function register()
+    {
+        $this->app->singleton(CssInlinerPlugin::class, function ($app) {
+            return new CssInlinerPlugin([]);
+        });
+
+        $this->app->afterResolving('mail.manager', function (MailManager $mailManager) {
+            $mailManager->getSwiftMailer()->registerPlugin($this->app->make(CssInlinerPlugin::class));
+            return $mailManager;
+        });
+    }
+}

app/Utils/CssInlinerPlugin.php

@@ -0,0 +1,140 @@
+<?php
+
+namespace App\Utils;
+
+use TijsVerkoyen\CssToInlineStyles\CssToInlineStyles;
+
+class CssInlinerPlugin implements \Swift_Events_SendListener
+{
+    /**
+     * @var CssToInlineStyles
+     */
+    protected $converter;
+
+    /**
+     * @var string[]
+     */
+    protected $cssCache;
+
+    /**
+     * @var array
+     */
+    protected $options;
+
+    /**
+     * @param array $options options defined in the configuration file.
+     */
+    public function __construct(array $options)
+    {
+        $this->converter = new CssToInlineStyles();
+        $this->options = $options;
+    }
+
+    /**
+     * @param \Swift_Events_SendEvent $evt
+     */
+    public function beforeSendPerformed(\Swift_Events_SendEvent $evt)
+    {
+        $message = $evt->getMessage();
+
+        if ($message->getContentType() === 'text/html'
+            || ($message->getContentType() === 'multipart/alternative' && $message->getBody())
+            || ($message->getContentType() === 'multipart/mixed' && $message->getBody())
+        ) {
+            [$body, $cssResources] = $this->messageSieve($message->getBody());
+            $css = $this->concatCss($cssResources);
+            $message->setBody($this->converter->convert($body, $css));
+        }
+
+        foreach ($message->getChildren() as $part) {
+            if (strpos($part->getContentType(), 'text/html') === 0) {
+                [$body, $cssResources] = $this->messageSieve($part->getBody());
+                $css = $this->concatCss($cssResources);
+                $part->setBody($this->converter->convert($body, $css));
+            }
+        }
+    }
+
+    /**
+     * Do nothing
+     *
+     * @param \Swift_Events_SendEvent $evt
+     */
+    public function sendPerformed(\Swift_Events_SendEvent $evt)
+    {
+        // Do Nothing
+    }
+
+    protected function concatCss(array $cssResources): string
+    {
+        $output = '';
+        foreach ($cssResources as $cssResource) {
+            $output.= $this->fetchCss($cssResource);
+        }
+
+        return $output;
+    }
+
+    protected function fetchCss(string $filename): string
+    {
+        if (isset($this->cssCache[$filename])) {
+            return $this->cssCache[$filename];
+        }
+
+        $fixedFilename = $filename;
+        // Fix relative protocols on hrefs. Assume https.
+        if (substr($filename, 0, 2) === '//') {
+            $fixedFilename = 'https:' . $filename;
+        }
+
+        $content = file_get_contents($fixedFilename);
+        if (! $content) {
+            return '';
+        }
+
+        $this->cssCache[$filename] = $content;
+
+        return $content;
+    }
+
+    protected function messageSieve(string $message): array
+    {
+        $cssResources = [];
+
+        // Initialize with config defaults, if any
+        if (isset($this->options['css-files'])) {
+            $cssResources = $this->options['css-files'];
+        }
+
+        $dom = new \DOMDocument();
+        // set error level
+        $internalErrors = libxml_use_internal_errors(true);
+
+        $dom->loadHTML($message);
+
+        // Restore error level
+        libxml_use_internal_errors($internalErrors);
+        $link_tags = $dom->getElementsByTagName('link');
+
+        /** @var \DOMElement $link */
+        foreach ($link_tags as $link) {
+            if ($link->getAttribute('rel') === 'stylesheet') {
+                array_push($cssResources, $link->getAttribute('href'));
+            }
+        }
+
+        $link_tags = $dom->getElementsByTagName('link');
+        for ($i = $link_tags->length; --$i >= 0;) {
+            $link = $link_tags->item($i);
+            if ($link->getAttribute('rel') === 'stylesheet') {
+                $link->parentNode->removeChild($link);
+            }
+        }
+
+        if (count($cssResources)) {
+            return [$dom->saveHTML(), $cssResources];
+        }
+
+        return [$message, []];
+    }
+}

config/app.php

@@ -181,7 +181,7 @@ return [
         App\Providers\MultiDBProvider::class,
         App\Providers\ClientPortalServiceProvider::class,
         App\Providers\NinjaTranslationServiceProvider::class,
-
+        App\Providers\MailCssInlinerServiceProvider::class,
     ],
 
     /*

config/css-inliner.php

@@ -0,0 +1,18 @@
+<?php
+
+return [
+
+    /*
+    |--------------------------------------------------------------------------
+    | Css Files
+    |--------------------------------------------------------------------------
+    |
+    | Css file of your style for your emails
+    | The content of these files will be added directly into the inliner
+    | Use absolute paths, ie. public_path('css/main.css')
+    |
+    */
+
+    'css-files' => [],
+
+];