[GitHubGistBridge] Add new bridge

Adds a new bridge for https://gist.github.com

The bridge generates feeds for comments on a particular gist based on
the gist ID or full URI. For better readability the general behavior
of code sections is manually restored with the original CSS styles
from GitHub.

bridges/GitHubGistBridge.php

@@ -0,0 +1,164 @@
+<?php
+
+class GitHubGistBridge extends BridgeAbstract {
+
+	const NAME = 'GitHubGist comment bridge';
+	const URI = 'https://gist.github.com';
+	const DESCRIPTION = 'Generates feeds for Gist comments';
+	const MAINTAINER = 'logmanoriginal';
+	const CACHE_TIMEOUT = 3600;
+
+	const PARAMETERS = array(array(
+		'id' => array(
+			'name' => 'Gist',
+			'type' => 'text',
+			'required' => true,
+			'title' => 'Insert Gist ID or URI',
+			'exampleValue' => '2646763, https://gist.github.com/2646763'
+		)
+	));
+
+	private $filename;
+
+	public function getURI() {
+
+		$id = $this->getInput('id') ?: '';
+
+		$urlpath = parse_url($id, PHP_URL_PATH);
+
+		if($urlpath) {
+
+			$components = explode('/', $urlpath);
+			$id = end($components);
+
+		}
+
+		return static::URI . '/' . $id;
+
+	}
+
+	public function getName() {
+		return $this->filename ? $this->filename . ' - ' . static::NAME : static::NAME;
+	}
+
+	public function collectData() {
+
+		$html = getSimpleHTMLDOM($this->getURI(),
+		null,
+		null,
+		true,
+		true,
+		DEFAULT_TARGET_CHARSET,
+		false, // Do NOT remove line breaks
+		DEFAULT_BR_TEXT,
+		DEFAULT_SPAN_TEXT)
+			or returnServerError('Could not request ' . $this->getURI());
+
+		$html = defaultLinkTo($html, static::URI);
+
+		$fileinfo = $html->find('[class="file-info"]', 0)
+			or returnServerError('Could not find file info!');
+
+		$this->filename = $fileinfo->plaintext;
+
+		$comments = $html->find('div[class="timeline-comment-wrapper"]');
+
+		if(is_null($comments)) { // no comments yet
+			return;
+		}
+
+		foreach($comments as $comment) {
+
+			$uri = $comment->find('a[href^=#gistcomment]', 0)
+				or returnServerError('Could not find comment anchor!');
+
+			$title = $comment->find('div[class="unminimized-comment"] h3[class="timeline-comment-header-text"]', 0)
+				or returnServerError('Could not find comment header text!');
+
+			$datetime = $comment->find('[datetime]', 0)
+				or returnServerError('Could not find comment datetime!');
+
+			$author = $comment->find('a.author', 0)
+				or returnServerError('Could not find author name!');
+
+			$message = $comment->find('[class="comment-body"]', 0)
+				or returnServerError('Could not find comment body!');
+
+			$item = array();
+
+			$item['uri'] = $this->getURI() . $uri->href;
+			$item['title'] = str_replace('commented', 'commented on', $title->plaintext);
+			$item['timestamp'] = strtotime($datetime->datetime);
+			$item['author'] = '<a href="' . $author->href . '">' . $author->plaintext . '</a>';
+			$item['content'] = $this->fixContent($message);
+			// $item['enclosures'] = array();
+			// $item['categories'] = array();
+
+			$this->items[] = $item;
+
+		}
+
+	}
+
+	/** Removes all unnecessary tags and adds formatting */
+	private function fixContent($content){
+
+		// Restore code (inside <pre />) highlighting
+		foreach($content->find('pre') as $pre) {
+
+			$pre->style = <<<EOD
+padding: 16px;
+overflow: auto;
+font-size: 85%;
+line-height: 1.45;
+background-color: #f6f8fa;
+border-radius: 3px;
+word-wrap: normal;
+box-sizing: border-box;
+margin-bottom: 16px;
+EOD;
+
+			$code = $pre->find('code', 0);
+
+			if($code) {
+
+				$code->style = <<<EOD
+white-space: pre;
+word-break: normal;
+EOD;
+
+			}
+
+		}
+
+		// find <code /> not inside <pre /> (`inline-code`)
+		foreach($content->find('code') as $code) {
+
+			if($code->parent()->tag === 'pre') {
+				continue;
+			}
+
+			$code->style = <<<EOD
+background-color: rgba(27,31,35,0.05);
+padding: 0.2em 0.4em;
+border-radius: 3px;
+EOD;
+
+		}
+
+		// restore text spacing
+		foreach($content->find('p') as $p) {
+			$p->style = 'margin-bottom: 16px;';
+		}
+
+		// Remove unnecessary tags
+		$content = strip_tags(
+			$content->innertext,
+			'<p><a><img><ol><ul><li><table><tr><th><td><string><pre><code><br><hr><h>'
+		);
+
+		return $content;
+
+	}
+
+}