Move HTML to Markdown library to Composer

vendor/league/html-to-markdown/src/Converter/HeaderConverter.php

@@ -0,0 +1,78 @@
+<?php
+
+namespace League\HTMLToMarkdown\Converter;
+
+use League\HTMLToMarkdown\Configuration;
+use League\HTMLToMarkdown\ConfigurationAwareInterface;
+use League\HTMLToMarkdown\ElementInterface;
+
+class HeaderConverter implements ConverterInterface, ConfigurationAwareInterface
+{
+    const STYLE_ATX = 'atx';
+    const STYLE_SETEXT = 'setext';
+
+    /**
+     * @var Configuration
+     */
+    protected $config;
+
+    /**
+     * @param Configuration $config
+     */
+    public function setConfig(Configuration $config)
+    {
+        $this->config = $config;
+    }
+
+    /**
+     * @param ElementInterface $element
+     *
+     * @return string
+     */
+    public function convert(ElementInterface $element)
+    {
+        $level = (int) substr($element->getTagName(), 1, 1);
+        $style = $this->config->getOption('header_style', self::STYLE_SETEXT);
+
+        if (($level === 1 || $level === 2) && !$element->isDescendantOf('blockquote') && $style === self::STYLE_SETEXT) {
+            return $this->createSetextHeader($level, $element->getValue());
+        }
+
+        return $this->createAtxHeader($level, $element->getValue());
+    }
+
+    /**
+     * @return string[]
+     */
+    public function getSupportedTags()
+    {
+        return array('h1', 'h2', 'h3', 'h4', 'h5', 'h6');
+    }
+
+    /**
+     * @param int    $level
+     * @param string $content
+     *
+     * @return string
+     */
+    private function createSetextHeader($level, $content)
+    {
+        $length = function_exists('mb_strlen') ? mb_strlen($content, 'utf-8') : strlen($content);
+        $underline = ($level === 1) ? '=' : '-';
+
+        return $content . "\n" . str_repeat($underline, $length) . "\n\n";
+    }
+
+    /**
+     * @param int    $level
+     * @param string $content
+     *
+     * @return string
+     */
+    private function createAtxHeader($level, $content)
+    {
+        $prefix = str_repeat('#', $level) . ' ';
+
+        return $prefix . $content . "\n\n";
+    }
+}