Refactor to OOP using pimple as DI container.

app.yaml

@@ -1,5 +1,5 @@
 application: comicfeeds-1022
-version: 2
+version: 3
 runtime: php55
 api_version: 1
 threadsafe: no

classes/DilbertService.php

@@ -0,0 +1,11 @@
+<?php
+
+class DilbertService extends GenericComicService {
+	public function __construct(FeedService $feedService, Logger $logger, StorageService $store) {
+		parent::__construct("dilbert_default", $feedService, $logger, $store);
+
+		$this->feed = "http://dilbert.com/feed.rss";
+		$this->pattern = '/data-image="(.+?)"/';
+		$this->entrySearchText = "Comic for ";
+	}
+}

classes/FeedService.php

@@ -0,0 +1,48 @@
+<?php
+
+class FeedService {
+	private $log;
+
+	public function __construct(Logger $logger) {
+		$this->log = $logger;
+	}
+
+	public function fetchFeed($url) {
+		$doc = simplexml_load_file($url);
+		if ($doc === FALSE) {
+			throw new Exception('Unable to load XML');
+		}
+		return $doc;
+	}
+
+	public function fetchPageContents($url) {
+		$contents = file_get_contents($url);
+		if ($contents === FALSE) {
+			throw new Exception('Unable to load page contents');
+		}
+		return $contents;
+	}
+
+	public function getLinkFromEntry(SimpleXMLElement $entry) {
+		$url = $entry->link['href'];
+		return $url;
+	}
+
+	public function getImageUrl($contents, $regexPattern) {
+		$ret = preg_match($regexPattern, $contents, $matches);
+
+		if ($ret === FALSE) {
+			throw new Exception("Regex error occurred.");
+		} elseif ($ret === 0) {
+			throw new Exception("Regex did not match subject.");
+		} elseif ($ret !== 1) {
+			throw new Exception("Unexpected regex return value: $ret");
+		} elseif (count($matches) < 2) {
+			throw new Exception("Regex had no matches.");
+		}
+
+		$imageUrl = $matches[1];
+
+		return $imageUrl;
+	}
+}

classes/GenericComicService.php

@@ -0,0 +1,76 @@
+<?php
+
+class GenericComicService {
+	protected $feed;
+	protected $feedService;
+	protected $log;
+	protected $pattern;
+	protected $entrySearchText;
+	protected $name;
+	protected $store;
+
+	public function __construct(
+		$name, FeedService $feedService,
+		Logger $logger, StorageService $store) {
+
+		$this->feedService = $feedService;
+		$this->log = $logger;
+		$this->name = $name;
+		$this->store = $store;
+	}
+
+	public function fetchAndStore() {
+		$xml = $this->fetch();
+		$filename = "feed_" . $this->name;
+		$this->store->save($filename, $xml);
+	}
+
+	protected function fetch() {
+		$doc = $this->feedService->fetchFeed($this->feed);
+
+		$count = count($doc->entry);
+		if ($count < 1) {
+			throw new Exception("No entries found in feed {$this->feed}.");
+		}
+
+		for ($i = $count - 1; $i >= 0; $i--) {
+			$entry = $doc->entry[$i];
+			if (strpos($entry->title, $this->entrySearchText) === FALSE) {
+				unset($doc->entry[$i]);
+			}
+			else {
+				$this->log->log("Processing $entry->title...");
+
+				if (isset($entry->description)) {
+					$entry->description = '';
+				} else {
+					$entry->addChild("description");
+				}
+
+				if (isset($entry->content)) {
+					unset($entry->content);
+				}
+
+				$newContents = $this->getEntryContents($entry);
+				$domNode = dom_import_simplexml($entry->description);
+				$owner = $domNode->ownerDocument;
+				$domNode->appendChild($owner->createCDATASection($newContents));
+				$this->log->log("\tDone.\n");
+			}
+		}
+		print_r($doc);
+		return $doc->asXml();
+	}
+
+	private function getEntryContents(SimpleXMLElement $entry) {
+		$url = $entry->link['href'];
+		$this->log->log("\tFetching URL: $url");
+		$contents = $this->feedService->fetchPageContents($url);
+
+		$imageUrl = $this->feedService->getImageUrl($contents, $this->pattern);
+
+		$newContents = "<img src=\"$imageUrl\"/>";
+
+		return $newContents;
+	}
+}

classes/Logger.php

@@ -0,0 +1,7 @@
+<?php
+
+class Logger {
+	public function log($text) {
+		echo $text . "\n";
+	}
+}

classes/StorageService.php

@@ -0,0 +1,24 @@
+<?php
+
+class StorageService {
+	private $prefix;
+	private $ctx;
+
+	public function __construct() {
+		$this->prefix = "gs://#default#/";
+		$options = ['gs' => ['Content-Type' => 'text/plain']];
+		$this->ctx = stream_context_create($options);
+	}
+
+	public function save($filename, $contents) {
+		file_put_contents($this->prefix . $filename, $contents, 0, $this->ctx);
+	}
+
+	public function load($filename) {
+		$newFilename = $this->prefix . $filename;
+		if (!file_exists($newFilename)) {
+			throw new Exception("Sorry. That feed does not exist.");
+		}
+		return file_get_contents($newFilename);
+	}
+}

classes/ViewService.php

@@ -0,0 +1,32 @@
+<?php
+
+class ViewService {
+	protected $log;
+	protected $store;
+
+	public function __construct(Logger $logger, StorageService $store) {
+		$this->log = $logger;
+		$this->store = $store;
+	}
+
+	public function getFeed($requestUri) {
+		$pattern = "@^/view/(.+?)/(.+?)$@";
+		$ret = preg_match($pattern, $requestUri, $matches);
+
+		if ($ret === FALSE) {
+			throw new Exception("Regex error occurred.");
+		} elseif ($ret === 0) {
+			throw new Exception("Regex did not match subject.");
+		} elseif ($ret !== 1) {
+			throw new Exception("Unexpected regex return value: $ret");
+		} elseif (count($matches) < 3) {
+			throw new Exception("Regex had no matches.");
+		}
+
+		$feedName = $matches[1];
+		$feedType = $matches[2];
+		$filename = "feed_{$feedName}_{$feedType}";
+
+		return $this->store->load($filename);
+	}
+}

composer.json

@@ -0,0 +1,5 @@
+{
+    "require": {
+        "pimple/pimple": "~3.0"
+    }
+}

php.ini

@@ -1,2 +1,2 @@
 google_app_engine.enable_functions = "libxml_disable_entity_loader"
-output_buffering = "Off"
+output_buffering = "On"

scripts/common.php

@@ -1,3 +1,21 @@
 <?php
 
+ob_start();
 libxml_disable_entity_loader(false);
+
+spl_autoload_register(function ($class) {
+    include __DIR__ . '/../classes/' . $class . '.php';
+});
+
+require(__DIR__ . '/../vendor/autoload.php');
+
+require('scripts/dependency_injection.php');
+
+set_exception_handler(function($ex) {
+    ob_end_clean();
+
+    header('Content-Type: text/plain');
+    http_response_code(500);
+
+    echo $ex->getMessage();
+});

scripts/dependency_injection.php

@@ -0,0 +1,20 @@
+<?php
+
+use Pimple\Container;
+
+$container = new Container();
+$container['logger'] = function($c) {
+    return new Logger;
+};
+$container['storage'] = function($c) {
+    return new StorageService;
+};
+$container['feed'] = function($c) {
+    return new FeedService($c['logger']);
+};
+$container['dilbert'] = function($c) {
+    return new DilbertService($c['feed'], $c['logger'], $c['storage']);
+};
+$container['view'] = function ($c) {
+    return new ViewService($c['logger'], $c['storage']);
+};

scripts/fetch_dilbert.php

@@ -3,7 +3,14 @@
 header("Content-Type: text/plain");
 require_once("common.php");
 
+$dilbert = $container['dilbert'];
+$dilbert->fetchAndStore();
+
+/*
+
 $feed = "http://dilbert.com/feed.rss";
+$pattern = '/data-image="(.+?)"/';
+
 $doc = simplexml_load_file($feed) or die('Unable to load XML');
 
 $count = count($doc->entry);
@@ -51,3 +58,4 @@ function get_image_url($contents) {
 print_r($outputXml);
 
 file_put_contents("gs://#default#/feed_dilbert_default", $outputXml);
+*/

scripts/view.php

@@ -1,6 +1,9 @@
 <?php
 
 require_once("common.php");
-
 header("Content-Type: application/rss+xml");
-echo file_get_contents("gs://#default#/feed_dilbert_default");
+header('Expires: ' . gmdate('D, d M Y H:i:s', time() + (60*60*2)) . ' GMT');
+header('Cache-Control: public, must-revalidate, max-age=7200');
+
+$view = $container['view'];
+echo $view->getFeed($_SERVER['REQUEST_URI']);