Reimplements HtmlParser using Symfony DomCrawler (#21)

Thanks a lot to @JohnathonKoster 🚀

README.md

@@ -102,6 +102,50 @@ Let's assume you want to style links inside lists differently than a general lin
 
 The ordering does not matter. Classify will take care of that for you.
 
+## Working With CSS Frameworks Like Tailwind CSS
+
+Some CSS frameworks utilize JIT compiling, or have some other means of purging CSS classes from production builds to reduce file sizes. Classify provides a Laravel Artisan command to generate a JavaScript configuration file containing all Classify class names that can be used when configuring your CSS build process.
+
+Running the following command from the root of the project:
+
+```
+php artisan classify:export
+```
+
+Would create a new (or update an existing) `classify.config.js` JavaScript file containing your Classify class name configuration:
+
+```js
+module.exports.classes = [
+    "mt-8",
+    "first:mt-0",
+    "text-xs",
+    "uppercase",
+];
+```
+
+This configuration file can be used in conjunction with your CSS framework's build tools. For example, we can add our Classify class names to the Tailwind CSS 3 safe list ([https://tailwindcss.com/docs/content-configuration#safelisting-classes](https://tailwindcss.com/docs/content-configuration#safelisting-classes)):
+
+Within `tailwind.config.js`:
+
+```js
+const classify = require('./classify.config');
+
+module.exports = {
+  content: [
+    './pages/**/*.{html,js}'
+    './components/**/*.{html,js}',
+  ],
+  safelist: [
+    ...classify.classes,
+    'bg-red-500',
+    'text-3xl',
+    'lg:text-4xl',
+  ]
+  // ...
+}
+```
+
+> **Important**: Remember to run the `php artisan classify:export` command after making these changes to your Tailwind CSS configuration file before you build your front-end assets!
 
 # More about us
 - [www.statamic-agency.com](https://statamic-agency.com)

composer.json

@@ -30,7 +30,9 @@
   "require": {
     "php": "^7.4 || ^8.0",
     "illuminate/support": "^8.0",
-    "statamic/cms": ">=3.0.38 || 3.1.* || 3.2.*"
+    "statamic/cms": ">=3.0.38 || 3.1.* || 3.2.*",
+    "symfony/dom-crawler": "^5.4",
+    "symfony/css-selector": "^5.4"
   },
   "require-dev": {
     "orchestra/testbench": "^6.0",

src/Commands/Export.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace VV\Classify\Commands;
+
+use Illuminate\Console\Command;
+
+class Export extends Command
+{
+    protected $signature = 'classify:export';
+    protected $description = 'Generates a JSON configuration file containing all Classify class names.';
+
+    /**
+     * Generates a JavaScript configuration file containing all Classify class names.
+     */
+    public static function getConfigurationContents(): string
+    {
+        $allConfig = config('classify');
+        $classNames = [];
+
+        foreach ($allConfig as $config) {
+            foreach ($config as $classList) {
+                $classes = collect(explode(' ', $classList))->reject(function ($class) {
+                    return strlen(trim($class)) == 0;
+                })->values()->all();
+
+                foreach ($classes as $class) {
+                    if (! in_array($class, $classNames)) {
+                        $classNames[] = $class;
+                    }
+                }
+            }
+        }
+
+        return 'module.exports.classes = '.json_encode($classNames, JSON_PRETTY_PRINT).';';
+    }
+
+    public function handle()
+    {
+        file_put_contents(base_path('classify.config.js'), self::getConfigurationContents());
+    }
+}

src/HtmlParser.php

@@ -2,30 +2,42 @@
 
 namespace VV\Classify;
 
+use Symfony\Component\DomCrawler\Crawler;
+
 class HtmlParser implements ClassifyParser
 {
     public function parse(Tag $tag, string $value): string
     {
-        return preg_replace(
-            $this->defineRegexPattern($tag),
-            $this->defineReplacement($tag),
-            $value
-        );
-    }
+        $selector = $tag->tag;
 
-    private function defineRegexPattern(Tag $tag): string
-    {
-        $pattern = '';
+        if (count($tag->before) > 0) {
+            $selector = implode(' > ', $tag->before).' > '.$selector;
 
-        foreach ($tag->before as $name) {
-            $pattern .= "<{$name}[^>]*>[^<]*";
+            $firstPart = strtolower($tag->before[0]);
+
+            // Guard against producing selectors in the form: body > body > span.
+            if ($firstPart != 'body') {
+                $selector = 'body > '.$selector;
+            }
         }
 
-        return "/({$pattern})(<{$tag->tag})(?! class)/iU";
-    }
+        $crawler = new Crawler($value);
+        $nodes = $crawler->filter($selector);
 
-    private function defineReplacement(Tag $tag): string
-    {
-        return "$1<{$tag->tag} class=\"{$tag->classes}\"";
+        if (count($nodes) == 0) {
+            return $value;
+        }
+
+        foreach ($nodes as $node) {
+            $node->setAttribute('class', $tag->classes);
+        }
+
+        // Generate the HTML with our class adjustments made.
+        $result = $crawler->html();
+
+        // Removes the <body> and </body> tags that get added since it's a fragment.
+        $result = substr($result, 6);
+
+        return substr($result, 0, -7);
     }
 }

src/Modifiers/Classify.php

@@ -26,9 +26,10 @@ public function index($value, $params, $context)
          * Convert style segment information into the Tag class.
          * They will get Sorted by count to parse nested tags first.
          */
+
         $segments = collect($this->getStyleSegments($styleSet))
             ->map(fn ($classes, $tags) => new Tag($tags, $classes))
-            ->sortByDesc('count');
+            ->sortBy('count');
 
         $segments->each(function ($segment) use (&$value) {
             $value = app(ClassifyParser::class)->parse($segment, $value);

src/ServiceProvider.php

@@ -11,6 +11,10 @@ class ServiceProvider extends AddonServiceProvider
         \VV\Classify\Modifiers\Classify::class,
     ];
 
+    protected $commands = [
+        \VV\Classify\Commands\Export::class,
+    ];
+
     public function boot()
     {
         parent::boot();

src/Tag.php

@@ -39,7 +39,15 @@ public function __construct(string $tags, string $classes)
      */
     private function convertTagsToArray(string $tags): array
     {
-        return explode(' ', $tags);
+        return collect(explode(' ', $tags))->reject(function ($tag) {
+            // Removes explicitly entered > symbols. These will be added
+            // back later when constructing the final CSS-style selector.
+            if ($tag == '>') {
+                return true;
+            }
+
+            return strlen(trim($tag)) == 0;
+        })->values()->all();
     }
 
     /*