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TIPS, INSIGHTS AND THE LATEST FROM THE EXPERTS BEHIND CAKEPHP

RSS Feeds, Fast and Easy

For my first entry, I am going to talk about how to create an RSS Feed on your website. RSS (Really Simple Syndication) is a format used to publish frequently updated works such as blogs or featured products. RSS defines a set of XML elements that are used to describe a channel or feed of information. An RSS feed is comprised of two parts, first is the metadata describing the channel and second is the records that make up the elements of the feed. RSS feeds allow your sites visitors to access the information on your site using software that reads these feeds. This will allow your site's visitors to stay up-to-date on the information on your site.

CakePHP allows for easy integration of RSS feeds into existing controller actions through the automatic router extension parsing. This allows us to specify what type of response we want from a URL through adding the proper extension to the URL such as http://www.yoursite.com/entries.rss. This alerts the router that your are asking for RSS formatted data in return. In addition, CakePHP has an RssHelper class that can be used to output parts of the metadata and elements in the feed through an easy to use helper.

Preparation

Before we begin making the feed we must alert the router that we want to allow for extensions to be parsed in the URL and that we want it to accept .rss as a valid extension. In your sites router file we add the following:

	Router::parseExtensions('rss');

Also for CakePHP to work it magic we must also have the RequestHandler in our controller's $components array. Now the router knows that we would like to parse urls that end in .rss as requesting RSS formatted responses. The next step of preparation is to add a default layout for rss feeds on your site. When you request a different format response the layout that is rendered will be selected from a sub-folder with the same name as the format. So in this case we would need a folder called /rss in the layouts folder in our CakePHP install. The view class will search for a file that has the same name as the layout that would be rendered if you were just rendering the html. In most cases this is the default.ctp layout file in the main layouts directory, but because we are requesting the response in RSS format we must add a default.ctp layout in the /layouts/rss/ sub-directory. This layout is our default RSS Feed layout.

	echo $rss->header();

	if (!isset($channel)) {
		$channel = array();
	}
	if (!isset($channel['title'])) {
		$channel['title'] = $title_for_layout;
	}

	echo $rss->document($rss->channel(array(), $channel, $content_for_layout));

Here in the layout our RssHelper shines through. We use the method RssHelper::channel() which generates the element and associated metadata elements. The $content_for_layout variable contains the output from the view. These then get passed to the RssHelper::document() method, which wraps the RSS document in the respective elements.

Controller

The controller needs no modification in the case of a simple RSS feed. This is because we are only adding a second view that is xml/rss to the action. The same data is used in both views and because CakePHP automatically sets the correct response type we don't need to tell it to render the correct view and layout for RSS. Here is the action method in the EntriesController for a basic view sorted by a published_date field and showing only if it is published.

	public function index() {
		$this->paginate['Entry'] = array(
			'conditions' => array('Entry.published' => 1),
			'order' => 'Entry.published_date DESC');
		$this->set('entries', $this->paginate());
	}

If you do have code that is specific for only the RSS view you can use the RequestHandler::isRss() to see if the action was called with the request for xml/rss formatting on response. This method returns a boolean value based on if the .rss extension was parsed in the URL.

	if ($this->RequestHandler->isRss()) {
		// RSS feed specific code goes here
	}

Note About Channel Metadata

It may feel right to put your metadata information in the index method in the controller, using Controller::set() to send the information to the views. This is inappropriate and is one of the most common snags that we have seen in the CakePHP community with creating RSS feeds. That information which is passed in the layout file to the RssHelper::channel() method should be set in the view using View::set() which will set the $channel variable for the layout in the view.

Views

As we had to put the layout in a subdirectory of the layouts folder we also need to create a view for the index action for the blogs controller. This is done by creating a directory /views/entries/rss/ which will hold our view file that will generate the RSS to render. You will need to add your RssHelper to the list of helpers in your controller so that it is automatically loaded in the view and the layout.

Our view begins by setting the $channel variable for the layout, this contains all the metadata for our RSS feed.

	$homeUrl = $html->url('/', true);
	$this->set('channel', array(
		'title' => __("Daniel's Recent Articles", true),
		'link' => $homeUrl,
		'description' => __("Most recent articles from Daniel.", true),
		'language' => 'en-us',
		'image' => array(
			'title' => 'Recent Articles from Daniel',
			'url' => FULL_BASE_URL . $this->webroot('/img/rss_feed_image', true),
			'link' => $homeUrl));

First we get the URL link for the website home that we will use for the links. Also we set the title, description and image to use for the RSS feed icon. By setting the channel variable using View::set() we are providing the layout the information to render the RSS feed's metadata elements.

The second part of the view generates the elements for the actual records of the feed. This is accomplished by looping through the data that has been passed to the view and using the RssHelper::item() method. The other method you can use, RssHelper::items() which takes a callback and an array of items for the feed. (The method I have seen used for the callback has always been called transformRss(). There is one downfall to this method, which is that you cannot use any of the other helper classes to prepare your data inside the callback method because the scope inside the method does not include anything that is not passed inside, thus not giving access to the TimeHelper or any other helper that you may need. The RssHelper::item() transforms the associative array into an element for each key value pair.

	foreach ($entries as $entry) {
		$postTime = strtotime($entry['Entry']['created']);

		$entryLink = array(
			'controller' => 'entries',
			'action' => 'view',
			'year' => date('Y', $postTime),
			'month' => date('m', $postTime),
			'day' => date('d', $postTime),
			$entry['Entry']['slug']);

		// This is the part where we clean the body text for output as the description 
		// of the rss item, this needs to have only text to make sure the feed validates
		$bodyText = preg_replace('=\(.*?)\=is', '', $entry['Entry']['body']);
		$bodyText = $text->stripLinks($bodyText);
		$bodyText = Sanitize::stripAll($bodyText);
		$bodyText = $text->truncate($bodyText, 400, '...', true, true);

		echo  $rss->item(array(), array(
			'title' => $entry['Entry']['title'],
			'link' => $entryLink,
			'guid' => array('url' => $entryLink, 'isPermaLink' => 'true'),
			'description' =>  $bodyText,
			'dc:creator' => $entry['Entry']['author'],
			'pubDate' => $entry['Entry']['created']));
	}

You can see above that we can use the loop to prepare the data to be transformed into XML elements. It is important to filter out any non-plain text charictars out of the description, especially if you are using a rich text editor for the body of your blog. In the code above we use the TextHelper::stripLinks() method and a few methods from the Sanitize class, but we recommend writing a comprehensive text cleaning helper to really scrub the text clean. Once we have set up the data for the feed, we can then use the RssHelper::item() method to create the XML in RSS format. Once you have all this setup, you can test your RSS feed by going to your site /entries/index.rss and you will see your new feed. It is always important that you validate your RSS feed before making it live. This can be done by visiting sites that validate the XML such as Feed Validator or the w3c site at http://validator.w3.org/feed/.

Latest articles

CakePHP Upgrade to 4 - Piece by Piece

Let's imagine you have a huge application in CakePHP 2.x (or 1.x) and you're planning to upgrade to the latest CakePHP 4.x. After doing some estimations, you realize the upgrade process is out of your scope, because you don't have the budget or developer availability to do it in 1 shot. At this point, some companies would abort the upgrade and keep working on 2.x for "some more time" until "this last release is delivered" or until "budget is available next fall", digging deeper and deeper into the rabbit hole…   There's an alternative you could follow if this is your case: proceed with the upgrade of a smaller portion of your application and let the 2 versions coexist for some time.   Warning: This is NOT for every project or company. Please carefully think about this decision as it has overhead you'll need to handle.   So, if your application has a portion that could be extracted, with a small set of dependencies from other areas of your application, or if you are creating a new feature with a limited set of dependencies with the rest of your application, this approach would be good for you.   In order to allow both applications to coexist, we are going to keep the CakePHP 1.x application as the main one, and use CakePHP 4.x as a subfolder inside of the first one. It's important to note that in order to share sessions between both applications you'll need to use a storage you can actually share, like database or cache based sessions (redis, etc). Then, you can use a configuration like this one (see below) to add a new upstream to handle your new application. Note: the upstream could be located in another server of your network, using a different PHP version etc.   We've used nginx as an example, but you can use the same approach in other web servers like Apache.   In our example we're going to use all paths starting with /api  to be managed by our new CakePHP 4.x application. upstream cake4 {      # Note this could be any server/port in your network where the cake4 application is installed          server 127.0.0.1:9090; }   # This is our CakePHP 2.x server server {     server_name example.com;       root   /var/virtual/example.com/app/webroot;     index index.php;       # All requests /api are forwarded to our CakePHP 4.x application location /api {         proxy_pass http://cake4;             proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;         proxy_set_header Host $host;             proxy_http_version 1.1;         proxy_set_header Upgrade $http_upgrade;             proxy_set_header Connection "Upgrade";     }       location / {             try_files $uri $uri/ /index.php?$args;     }       location ~ \.php$ {           try_files $uri =404;           include fastcgi_params;                fastcgi_pass unix:/run/php/php7.4-fpm.sock;           fastcgi_index index.php;             fastcgi_intercept_errors on;         fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;     } }   # This is our CakePHP 4.x server server {     listen 9090;     server_name example.com;       root   /var/virtual/cake4-example.com/webroot;     index index.php;       location / {         try_files $uri $uri/ /index.php?$args;     }       location ~ \.php$ {         try_files $uri =404;             include fastcgi_params;         fastcgi_pass unix:/run/php/php7.4-fpm.sock;             fastcgi_index index.php;         fastcgi_intercept_errors on;             fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name;     } }   As you can see, we have 3 blocks defined in our configuration file:

  • upstream cake4 {...} to forward requests to the CakePHP 4.x application
  • server {... 2.x ...} using a location /api to forward all these calls to the CakePHP 4.x server
  • server {... 4.x ...} using a specific port (9090) to handle requests in CakePHP 4.x
  Using this approach, you can break your application into 2 parts, and start moving features by path to CakePHP 4. You'll need to handle the changes in 2 projects for a while, and pay this overhead,  but this could be better to maintain than a CakePHP 2.x application sitting on an old PHP version. Happy baking!  

Dependency Injection with CakePHP

Dependency Injection is some of the bigger buzzwords in PHP frameworks.  Historically, CakePHP application logic didn’t support that, until the version 4.2 was released last December. You can do that on your own and have a few plugins for that. This is a new chapter of the framework, let's see how to bake it.  

Use Case

First, let’s talk about a classic Use case on real applications. Our application will include an address form, such as the shipping address for an online order, or provide information about User, Company, etc. Autocomplete can help users supply the details.   We will use the Geocoding API from Google Maps Platform, making a HTTP request for API with json output format and address parameter: https://maps.googleapis.com/maps/api/geocode/json?address=89104&key=****** And here we go, we will get this result:  

Baking a Address Service

After seeing the Use case, all we need on our backend is to make a HTTP request for API and return the JSON result for the frontend to populate related fields.   1. First, let’s exposing our application for accept “.json” requests:   2. Now, we can bake a Address Controller and let’s request an empty result: $ ./bin/cake bake controller Address --actions index   Now our app requests /address.json will return an empty JSON.   3. Let’s bake (manually) the Address Service:   Basically I’m using Cake\Http\Client to make the API request. Also I read Geocode.key from Cake\Core\Configure, we don't want to expose our key on public requests (add the key on config/boostrap.php).   4. Let’s rewrite our Controller:   5. Finally, let’s add our Service on Application.php:   That’s all bakers! Now our endpoint /address.json will support query parameters and return the result of the API request.  

The cost of shiny

I’m here selling an idea and I don't start with the cons. Unfortunately, the Dependency Injection container is an experimental feature that is not API stable yet.  The support is a bit limited, CakePHP will inject services into: constructors of Controllers and Commands and Controller actions. The core team hopefully stabilizes the feature on version 4.3, or at most 4.4. They need your help testing and finding cases, and feedback always is welcome.   I hope this post can be useful for you and your projects.  See you next time!  

Planning For Your Upgrade

Having a successful upgrade implies not only upgrading the code itself, but also identifying the different tasks that will be part of the Upgrade Plan. Making a good plan for an upgrade requires identifying the current status of the application. A good plan is based upon clear, well-defined, and easily understood objectives.   After years of experience with CakeDC making upgrades, migrating applications from CakePHP 1 to CakePHP 4 in all possible combinations, we have noticed there are a set of elements or characteristics that are useful to evaluate and identify before starting the upgrade. Having a clear understanding of these elements will be helpful to define the different tasks that will be included in the Upgrade Plan, and reduce any risk while upgrading and delivering.   Imagine that you want to run a marathon - but before starting any of the thousands of plans you can find on the internet about “How to run a Marathon”, you must know where you are. You could ask yourself:  How many miles per week are you currently running? What is the base training needed to start this program? What is the distance of your longest run in the past 3 weeks? How many days per week do you have available to exercise?, etc. This will help you to choose the plan that better fits you. It’s important to identify where you are, where you want to get and how to get where you want.    Wondering how  to evaluate where you are for the Upgrade? Evaluate the status of your application. You could consider the following points as reference:

  • What is your current CakePHP version? 
  • Identify the weaknesses and the strength of the current code by making a code review.
  • Identify the versions of the packages, plugins, libraries that your application is using. 
  • If you are using CakePHP Third Party plugins, figure out if those plugins have already been upgraded.
  • Identify any third party integration and how the upgrade could affect it. 
  • What is the unit test coverage, if any? 
  • Is there any existing documentation?
  • Is there any custom change in the CakePHP core? (I hope there is not!)
  The complexity, time, cost, and resources required to upgrade your application will depend on the status of your application. Once you know where you are, it’s the time to plan how to get where you want.  Let’s talk about this in a future article. In case you are looking for some guidance on preparing your Upgrade Plan, don’t hesitate to contact us, we could help you to identify your current status, define the plan and execute the whole plan for you. We can also work together with your team on the upgrade, helping them understand the upgraded codebase so you can maintain the project with your own team as you did before.  

We Bake with CakePHP