Allow nested selectors (#12)

This PR allows for nested selectors. You can for example only target p-tags inside a list:

 ```php
 'li p' => 'my-css-class', 
```

This wasn't possible before.

README.md

@@ -5,49 +5,39 @@
 
 ## Usage
 
+There might be cases, if for example using [TailwindCss](https://tailwindcss.com), where you want to use custom classes to style your output.
+
 ### Getting started
 ```php
 use VV\Markdown\Facades\Markdown;
 
 Markdown::parse($yourContent); // The outpul will be HTML
 ```
 
-### Output styling
-
-#### Basic
-You can always format your markdown by using a wrapper of some kind. 
-```css
-.markdown h1 {
-    font-weight: bold;
-    ...
-} 
+### Configuration
+To add or change style sets, simply add or change an array with classes that should be added to the HTML tag.
+```php
+'default' => [
+    'h1' => 'text-2xl',
+    'a'  => 'link hover:text-blue',
+    'p' => 'mb-5',
+    'li p' => 'mb-2 ml-4',
+],
 ```
+*This example uses TailwindCSS, but you can use whatever kind of CSS you want.*
 
+### Example Output
 ```html
-<div class="markdown">
-    <!-- Auto generated output -->
-    <h1>Headline</h1>
-    <p>Some text</p>
-</div>
-```
+<h1 class="text-2xl">A headline</h1>
+<p class="mb-5">Some text</p>
 
-### Custom classes
-There might be cases, if for example using [TailwindCss](https://tailwindcss.com), where you want to use custom classes to style your output. 
+<ul>
+    <li><p class="mb-2 ml-4">A list item</p></li>
+    <li><p class="mb-2 ml-4">A list item</p></li>
+    <li><p class="mb-2 ml-4"><a class="link hover:text-blue" href="#">Klick me</a></p></li>
+</ul>
 
-```php 
-// config/markdown.php
-'styles' => [
-    'default' => [
-        'h1' => 'text-2xl',
-        'p' => 'mb-2',
-    ],
-    ...
-```
-
-The output would look like this
-```html
-<h1 class="text-2xl">Headline</h1>
-<p class="mb-2">Some text</p>
+<p class="mb-5">Another text</p>
 ```
 
 #### Multiple styles
@@ -75,7 +65,6 @@ Markdown::style('wiki')->parse($yourContent);
 No need to define default. If nothing has been provied, markdown will look for the default style.
 
 
-
 # More about us
 - [www.visuellverstehen.de](https://visuellverstehen.de)
 

src/Markdown/AddCustomHtmlClasses.php

@@ -4,8 +4,19 @@
 
 class AddCustomHtmlClasses
 {
+    /**
+     * The content the class will parse.
+     */
     public string $content;
+
+    /**
+     * The chosen style which normaly would be `default`.
+     */
     public string $style;
+
+    /**
+     * The belonging style stet as defined inside the config file.
+     */
     public array $styleSet;
 
     public function __construct(string $content, string $style)
@@ -21,29 +32,56 @@ public function __construct(string $content, string $style)
      */
     public function handle(): string
     {
-        foreach ($this->styleSet as $tag => $class) {
-            $this->content = str_replace($this->tagFilter($tag), $this->replaceTag($tag, $class), $this->content);
-        }
+        // Fetching all style sets and ordering them after the count.
+        $tags = collect($this->getStyleSet())
+            ->map(fn ($classes, $tags) => new Tag($tags, $classes))
+            ->sortByDesc('count');
+
+        // Parse the content for every defined style set.
+        $tags->each(function ($tag) {
+            $this->content = $this->parse($tag, $this->content);
+        });
 
         return $this->content;
     }
 
     /**
-     * Build the string we want to replace.
+     * Is parsing the content and will add classes to the html-tags.
      */
-    private function tagFilter(string $tag): string
+    public function parse(Tag $tag, string $value): string
     {
-        return "<{$tag}";
+        return preg_replace(
+            $this->defineRegexPattern($tag),
+            $this->defineReplacement($tag),
+            $value
+        );
+    }
+
+    /*
+     * Defines the regex pattern and does take nested selectors into account.
+     */
+    private function defineRegexPattern(Tag $tag): string
+    {
+        $pattern = '';
+
+        foreach ($tag->before as $name) {
+            $pattern .= "<{$name}[^>]*>[^<]*";
+        }
+
+        return "/({$pattern})(<{$tag->tag})(?! class)/iU";
     }
 
     /**
-     * Replace the filtered tag and add custom css classes.
+     * Does add the needed classes into the html tag.
      */
-    private function replaceTag(string $tag, string $class): string
+    private function defineReplacement(Tag $tag): string
     {
-        return "<{$tag} class=\"{$class}\"";
+        return "$1<{$tag->tag} class=\"{$tag->classes}\"";
     }
 
+    /**
+     * Get the style sets from the config for the chosen style set.
+     */
     private function getStyleSet(): array
     {
         $configPath = 'markdown.styles.'.$this->style;

src/Markdown/CommonMarkRepository.php

@@ -7,6 +7,7 @@
 class CommonMarkRepository implements MarkdownRepository
 {
     public GithubFlavoredMarkdownConverter $parser;
+
     public string $style = 'default';
 
     public function __construct(array $config)
@@ -17,11 +18,9 @@ public function __construct(array $config)
     public function parse(string $content): string
     {
         $content = $this->parser->convertToHtml($content);
+        $content = (new PrefixImageSources($content))->handle();
 
-        return (new PrefixImageSources(
-            (new AddCustomHtmlClasses($content, $this->style))->handle()
-        )
-        )->handle();
+        return (new AddCustomHtmlClasses($content, $this->style))->handle();
     }
 
     public function style(string $style): self

src/Markdown/Tag.php

@@ -0,0 +1,61 @@
+<?php
+
+namespace VV\Markdown\Markdown;
+
+class Tag
+{
+    /*
+    * Contains the parent tag, which might be the only or last tag defined in the config.
+    * From a list like `ul li p` it would fx be `p`.
+    */
+    public string $tag;
+
+    /*
+    * If multiple tags have been defined, those are the tags before the parent tag.
+    * From a list like `ul li p` it would fx be `ul li`.
+    */
+    public array $before;
+
+    /*
+    * Contains the class list as defined in the config.
+    */
+    public string $classes;
+
+    /*
+    * Defines the number of tags, including the parent tag.
+    */
+    public int $count;
+
+    public function __construct(string $tags, string $classes)
+    {
+        $tags = $this->convertTagsToArray($tags);
+        $this->count = count($tags);
+        $this->classes = $classes;
+        $this->setTags($tags);
+    }
+
+    /*
+    * It's easier to handle tags as an array, so we'll convert them.
+    */
+    private function convertTagsToArray(string $tags): array
+    {
+        return explode(' ', $tags);
+    }
+
+    /*
+    * Set the parent tag and save all other tags in the before attribute.
+    */
+    private function setTags(array $tags): void
+    {
+        $this->tag = $this->setParentTagAndRemoveFromOriginalArray($tags);
+        $this->before = $tags;
+    }
+
+    /*
+    * Get the key from the last array and splice / remove it.
+    */
+    private function setParentTagAndRemoveFromOriginalArray(array &$tags)
+    {
+        return array_splice($tags, array_key_last($tags))[0];
+    }
+}

tests/Unit/CommonMarkTest.php

@@ -78,9 +78,94 @@ public function it_can_parse_lists()
 <li>Second item</li>
 <li>Third item</li>
 <li>Fourth item</li>
-</ul>';
+</ul>
+';
 
-        $this->assertStringcontainsString($result, Markdown::parse($toParse));
+        $this->assertEquals($result, Markdown::parse($toParse));
+    }
+
+    /** @test */
+    public function a_nested_tag_will_be_recognized()
+    {
+        config()->set('markdown.styles.default', ['li p' => 'text-sm']);
+
+        $toParse = '<li><p>Some text</p></li>';
+        $result = '<li><p class="text-sm">Some text</p></li>
+';
+
+        $this->assertEquals($result, Markdown::parse($toParse));
+    }
+
+    /** @test */
+    public function a_nested_tag_with_text_inbetween_will_be_recognized()
+    {
+        config()->set('markdown.styles.default', ['a span' => 'text-red']);
+
+        $toParse = '<a>Some <span>styled</span> text</a>';
+        $result = '<p><a>Some <span class="text-red">styled</span> text</a></p>
+';
+
+        $this->assertEquals($result, Markdown::parse($toParse));
+    }
+
+    /** @test */
+    public function a_nested_tag_with_text_inbetween_will_be_recognized_on_multilines_as_well()
+    {
+        config()->set('markdown.styles.default', ['li p' => 'text-bold']);
+
+        $toParse = <<<'EOT'
+                     <li>Bad formatted HTML
+                        <p>Some more</p>
+                     </li>
+                     EOT;
+
+        $result = <<<'EOT'
+                  <li>Bad formatted HTML
+                     <p class="text-bold">Some more</p>
+                  </li>
+
+                  EOT;
+
+        $this->assertEquals($result, Markdown::parse($toParse));
+    }
+
+    /** @test */
+    public function a_nested_tag_with_already_defined_classes_will_be_parsed_correctly()
+    {
+        config()->set('markdown.styles.default', ['a span' => 'text-red']);
+
+        $toParse = '<a href="#">Some<span>thing</span></a>';
+        $result = '<p><a href="#">Some<span class="text-red">thing</span></a></p>
+';
+
+        $this->assertEquals($result, Markdown::parse($toParse));
+    }
+
+    /** @test */
+    public function a_nested_tag_will_be_replaced_and_wont_be_overwritten()
+    {
+        config()->set('markdown.styles.default', [
+            'p'    => 'single',
+            'li p' => 'nested',
+        ]);
+
+        $toParse = <<<'EOT'
+                     <li>
+                        <p>I am nested</p>
+                     </li>
+                     
+                     <p>I am not</p>
+                     EOT;
+
+        $result = <<<'EOT'
+                          <li>
+                             <p class="nested">I am nested</p>
+                          </li>
+                          <p class="single">I am not</p>
+
+                          EOT;
+
+        $this->assertEquals($result, Markdown::parse($toParse));
     }
 
     /** @test */