Tag Archives: PHP

A Case for WordPress

I recently made the case for using the open-source WordPress CMS instead of a custom hand-rolled CMS to a manager. What follows is the email (with names and companies changed) that was sent. I thought that it might be useful to other people who are trying to convince their organization to take the leap to WordPress, Drupal, or any other open-source CMS. It’s also worth noting that I’m on very friendly terms with my manager, hence the informality and straight-forwardness. As for the Django references, we develop most of our data-driven sites in Python/Django.

Hey [Manager],

As you already know, I completely loathe the [Custom] CMS. My recent and ongoing experiences with the [Client] website have only served to reinforce these feelings. Unbridled hate rarely serves any useful purpose though, so I’ve decided to see what I can do to make the problem better. My way of doing that is by making a case for using WordPress on large, non-trivial, content driven websites. As of right now WordPress has been lasso’d into small-size websites at [Company], but I believe it is capable of far more then that. What follows is a breakdown of all the feedback, questions, and concerns that were raised while I was gathering information. I’ve provided solutions to almost all of the problems, and its worth noting that some of the problems with WordPress are not unique to WordPress. I also want to make it clear that I’m not trying to get rid of the [Custom] CMS, especially since we have a lot of clients with a lot of money invested in it. I’m simply making a case for using WordPress on large sites instead of the [Custom] CMS.

Content Creation / Management

For as long as I can remember, [Other Manager] always raised a red flag with WordPress because it was inferior in content creation to the CMS. In vanilla form this is arguably true, however WordPress has an amazing community of plugin developers surrounding it who have solved all of these problems.

  • Pods – I have a love-hate relationship with pods. I like that they provide nearly infinite flexibility to the content creator, but that comes with the price of nearly infinite complexity. While I disagree with giving the content-creator that much control over how content is displayed, I can see the usefulness of it. To solve that problem, there are many visual composition plugins available for WordPress. My favorite is Visual Composer (http://vc.wpbakery.com/). Extending Visual Composer (akin to adding “module functions”) is as simple as adding a hook in your WordPress widget.
  • Categories / Taxonomies for Media (assets) – WordPress has brilliant support for categories and custom taxonomies out of the box. Beyond that, it also has support for tags. One thing that doesn’t work out of the box is media categories. Luckily there is a large handful of community plugins that easily solve this problem for us.
  • Media – The media library in WordPress is extremely slick, ajax-y (asynchronous uploads, etc), and easily extendable. Multiple thumbnails and image sizes are generated out of the box. Adding new image sizes is easy too.
  • Videos – WordPress supports videos out of the box. Adding Youtube/Hulu/Vimeo videos is as easy as adding one of the numerous plugins. There are even plugins out there that interface with FFMPEG to get you a nice selection of thumbnails to choose from.
  • Form Builder – The new hotness of [Custom] CMS is Form Builder. WordPress has a large amount of awesome form builders available, and most of them are cheap and come with support. Gravity Forms(http://www.gravityforms.com) is my favorite. Although Ninja forms is looking like a valid alternative.
  • User Management – WordPress comes with excellent user management out of the box. It has 4 default roles (Administrator, Editor, Contributor, Subscriber), but no way to change what those roles are capable of. They generally have pretty sane defaults, but sometimes you want to tweak things. User Role Editor(http://wordpress.org/plugins/user-role-editor) provides an easy way to modify group and user permissions. If you need to add new roles, there are plugins for that as well.
  • Content Deployment – We’ve often struggled with how to deploy new content to sites. Generally you don’t want to create the content on live, because it will need to be hidden. There is a straight ballin’ plugin for WordPress called Ramp(http://crowdfavorite.com/wordpress/ramp/) that solves this problem. Seriously, check this out. It will blow your mind.

General Notes

I have a handful of notes that don’t fit well into Content Creation / Management or Development, so here we go.

  • Update Cycle – WordPress has a release cycle (http://en.wikipedia.org/wiki/WordPress#Releases). It has feature releases, bug releases, and HOLY HELL THATS A BIG RELEASE releases. WordPress updates are vetted by an insanely large community of professional developers who catch bugs/regressions and fix them before release.
  • CMS “Upgrades” – Somehow its become normal and accepted at [Company] that a CMS Upgrade costs north of $25,000, takes a month, and almost always ends up braking some part of the site that wasn’t broken before. WordPress upgrades take 10 seconds, don’t break changes, and have deprecation warnings just in case you’re using a method/hook that won’t be supported in a future release. We might make some money off of [Custom] CMS upgrades, but my experience has been that they end up costing more time/effort/good will then they are worth. Having a one-click upgrade option allows us to keep our sites secure, up to date, and gets us back to making things awesome.
  • Community – WordPress.org has 1,998 base themes that can be used and extended via theme inheritance. It also has over 26,000 plugins that extend WordPress’ functionality. This doesn’t account for the numerous premium plugins that are available throughout the internet. Help is always just a Google search away. If that doesn’t work, Stack Overflow most certainly will. Having the backing of a community while you are developing is invaluable. Did I mention the WordPress IRC channel?
  • Documentation – One of the most frustrating things about the [Custom] CMS isn’t the lack of code documentation, but the lack of code usage documentation. WordPress has a ludicrous amount of documentation on pretty much anything you can think of. It stays up to date with best practices and is updated for every release. If the WordPress.org documentation isn’t good enough, the source code is very well documented. If the source doesn’t suit your fancy, there is probably a blogger that wrote about your problem.
  • Hiring – Hiring is hard in this economic climate. Selling a PHP developer to come work for [Company] with [Custom] CMS is even harder. If the person is a WordPress expert, all of that domain knowledge stagnates and becomes useless here. It also makes the on-boarding process take 2-4 months. And even then, they still aren’t all that useful in the [Custom] CMS. Having WordPress as a core tool allows us to hire people who are already experts. The on-boarding becomes a few weeks, and everyone is happy. It also makes it a lot less fatal if we lose a developer, because it’s possible to hire another one that already has all the domain knowledge.
  • Focus – Using WordPress is similar to using Django in that it gets out of your way at lets you focus on what’s important: making awesome stuff. You don’t have to piddle around with random regressions, bugs, or odds and ends. Those are already worked out for you. You get to focus on making custom functionality the best you can. Not having to mess around with bugs and regressions allows you to focus on quality instead of just “getting it done”.
  • Security – WordPress can be a security nightmare. With an install footprint of over 60 million websites (as of 2012), everybody is trying to hack it. Luckily most plugin authors and the WordPress security team are always right on top of it. There is a plugin called WP Security Scan(http://wordpress.org/plugins/wp-security-scan/) that takes care of making sure all the directories have the proper permissions, and in general gives good advice to harden your WordPress installation. Taking 10 minutes a week to update all your WordPress sites is also the best way to prevent security issues.
  • Who? – WordPress.com has a nice list of notable WordPress users (http://en.wordpress.com/notable-users/). The list includes, CNN, NYTimes, Forbes, Reuters, Sony, Jay-Z, Rolling Stones, GM, and others.
  • Cost – We keep upgrading the CMS. It needs it, but it cost lots of money. WordPress and the open-source community keep things up-to-date for us, so the cost is nil.

Development

In the past, a lot of misinformation has been spread about WordPress and how developing with it is awful. A lot of that comes from lack of knowledge, so I thought I’d address a lot of the pain points that people have experienced.

  • Plugin Creation – [Other developer] brought up the point that WordPress plugins are created in a procedural fashion, and are therefore a huge PITA to work with. As it turns out, the correct way to make WordPress plugins is via OOP. This NetTuts tutorial covers most of the basics (http://net.tutsplus.com/tutorials/wordpress/create-wordpress-plugins-with-oop-techniques/).
  • Content Deployment – WordPress hard-codes URLs into the database content. This is obviously a bad idea for many reasons. To rectify, if you move content from one server to another, you just need to execute 3 sql queries as part of your deployment. Usage of Ramp (mentioned above) solves this issue for 99% of use cases.
  • Versioning – WordPress shouldn’t be versioned. Any plugin you install from WordPress.org should not be versioned. If you are making a custom theme, that should get it’s own repository (hey, look at Stash and all it’s repos we can create). If you are making a custom plugin, that should also get it’s own repo. This promotes re-usability and good coding practices. Deployment of theme/plugin updates is as easy as checking out the latest version or git-pulling.
  • Deployment – Initial deployment of a WordPress site is just like moving a staging site to the live server for the [Custom] CMS. After that, deploying code updates to custom plugins and themes is just a git pull/checkout of a tag. This could easily be streamlined with the use of Fabric or Capistrano.
  • Modules / Custom Post Types – The [Custom] CMS has a pretty nice way of creating basic custom content via modules and the scaffolding. WordPress has custom post types, and several different plugins for creating them on the fly. My current favorite is Advanced Custom Fields (http://www.advancedcustomfields.com/)
  • Theme Inheritance – As mentioned before, WordPress has LOTS of themes. Nearly any one of them can be used as a base theme, saving front-enders a ton of time getting base CSS and templates set up.
  • ORM – WordPress has a weak ORM. Hopefully you can use WordPress’ features enough that you can write minimal SQL. On the bright side, you’ll have some nicely optimized queries ;) This is also why you should use the right tool for the job. If you have to interact with the database so much that you need an ORM, you should probably be using a framework.
  • Testing – WordPress core is fully unit and integration tested. The majority of premium plugins and popular plugins are tested as well. Plugins can easily be tested using PHPUnit, and their interfaces can be tested using Behat.
  • Developing as a Team – WIth a sane Git strategy (custom plugins and themes versioned only) developing as a team is a non-issue. In the past, having the whole project under version control caused serious issues when there was more then one developer.
  • Database Migrations – Just as with [Custom] CMS, if you have complex migration that destroys data you’ll need to handle the migration yourself. http://codex.wordpress.org/Creating_Tables_with_Plugins has more info. If the migration isn’t destructive, you can use the wp_delta method to handle it for you.
  • Environment Abstraction – WordPress does a great job of not caring about what version of PHP you’re on. So long as you are PHP >= 5.2.4 and MySQL >= 5.0.0, you’re all set

I know we’ve talked in the past about vetting a Django CMS, but I think that using WordPress is the best choice. We already have people who know it, the front-enders know how to develop for it, the community is massive, and learning it is easy. I look forward to talking with you about this.

PHP Dark Arts: References

Remember the first time you dabbled in C?  Oh, the glorious typing, functions, and structs!  Now do you remember the first time you ran in to a pointer?  ‘*’, ‘&’, ‘->’ all made your hurt, but eventually you figured it out.  It’s fortunate (depending how you look at it) that we don’t have need to dabble with pointers or references while web programming these days.  However, PHP does allow us to passing things around by reference.  It’s not used often, but when used correctly can be very beneficial to the quality of your code.

What are PHP references?

The first thing you need to know about PHP references is that they are not C references.  You can’t do pointer arithmetic on them because they aren’t actually addresses.  In PHP references are actually symbol table aliases.  This means that you can have 2 variable names sharing the same variable content.

What can you do with references?

There are 3 things that you can do with PHP references.

  • Assign by reference.
  • Pass by reference.
  • Return by reference.
$x =& $y;
$x = 3;
echo "X: $x, Y: $y";

The above code sets $x and $y’s references to the same content area. Therefore, when $x is assigned 3, $y has access to the same data.

function add_item(&$item) {
   	$item++;
}
 
$totalItems = 0;
for($i = 0; $i <; 5; $i++) {
	add_item($totalItems);
}
echo "Total items: $totalItems";

This code allows you to modify a variable’s value without ever returning anything. In this example I made a simple counter, but you can set the value of $item to anything and it should work out just fine.

class Test {
	public $count = 0;
 
	public function &getCount() {
		return $this->count;
	}
}
 
$t = new Test();
$value = &$t->getCount();
$t->count = 25;
echo $value;

This code returns a reference to the public $count variable of the Test class. Generally this isn’t best practice, as it lowers the readability of the code.

Unsetting References

In the event that you want to free a variable from it’s reference to another, you can simply use the unset function.

$x =& $y;
unset($x);

HTML 5 Canvas: Saving to a File with PHP

So you’ve finally discovered the wonder that is the HTML5 Canvas element. Great! If you’re like me, the first thing I wanted to do with it was doodle on it. I eventually worked out how to map touch/mouse events to the canvas and draw lines, but I wanted to save my creations!

As it turns out, the Canvas element has a method called toDataURL(), which base64 encodes the entire Canvas element and returns it as a string. From there, you can just pump it over to a server and handle it from there. Here’s the step-by-step, which assumes you are also running jQuery on your site.

Step 1: Save the canvas and POST the data

var data = document.getElementById("myCanvasID").toDataURL();
$.post("process.php", {
	imageData : data
}, function(data) {
	window.location = data;
});

Step 2: Process the POST data, and save it to a file.

$data = substr($_POST['imageData'], strpos($_POST['imageData'], ",") + 1);
$decodedData = base64_decode($data);
$fp = fopen("canvas.png", 'wb');
fwrite($fp, $decodedData);
fclose();
echo "/canvas.png";

Note: The first line of this script removes the header information that is sent with the encoded data.

Thats all there is to it. You can now easily save your HTML 5 awesomeness.

Caching WordPress Data with the Transients API

If you’re a plugin or theme developer, there may come a time when you need to execute a long running operation. It doesn’t need to be anything complicated, but something as simple as fetching a Twitter feed can take a significant amount of time. When you come across these types of situations, it’s handy to be able to store the data on your own server and then fetch a new copy of it every X hours. This is called caching, and WordPress convieniently comes packages with an excellent caching API called Transients .
Wordpress Transients API

The Transients API is surprisingly simple to use. In fact, it’s very much like using set_option and get_option except with an expiration time. If you aren’t familiar with caching at all, here’s the general workflow:

  1. If the data exists in the cache and isn’t expired, get it.
  2. If the data doesn’t exist in the cache or is expired, perform the necessary actions to get the data.
  3. Store the data in the cache if it doesn’t already exist or is expired.
  4. Continue from here using data.

When attempting to use the Transients API for caching, there are three functions that you need to be aware of: set_transient, get_transient, and delete_transient.

  • set_transient($identifier, $data, $expiration_in_minutes): This function stores your data into the database. The identifier is a string that uniquely identifies your data. Your data can be any sort of complex object, so long as it is serializable. The expiration is how long your want your data to be valid (ex: 12 hours would be 60*60*12).
  • get_transient($identifier): This retrieves your data. If the data doesn’t exist or the expiration time has passed, false is returned. Otherwise, the same data you stored will be returned.
  • delete_transient($identifier): This will delete your data before it’s expiration time. This is handy if you are storing post-dependent data because you can hook it into the save action so that every time you save a post, your cached data is cleared.

Now that we’ve covered the basics, how about a quick example?

if (false === ( $my_data = get_transient('super_expensive_operation_data') ) ) {
     $my_data = do_stuff();
     set_transient('super_expensive_operation_data', $my_data, 60*60*12);
}
 
echo $my_data;
 
function do_stuff() {
     $x = 0;
     for($i = 0; $i != 999999999; $i++) {
          $x = $x * $i;
     }
     return $x;
}

The example is pretty straight forward. We first check to see if there is a cached copy of the data, if not, we fetch the data from the “do_stuff” function, and store it in the database. Simple, right?

One of the benefits of using the Transients API (aside from speeding your site up) is that plugins like WP Super Cache or WP Total Cache will auto-magically cache your data into memcached if you have it set up. For you, this means an even faster site! If you have any questions about caching techniques or the Transients API, leave a comment and I’d be happy to help.

Tracking Email Open Time with PHP

You can download my code for this article here.
Some time ago I had great aspirations of launching a web company that does email tracking and analytics. One of the things that I really wanted to figure out but wasn’t well documented on the web was how to track how long a user had a particular email open. When a company like MailChimp wants to track emails that they are sending out, they put a small image in the email called a “beacon”. When the user opens the email, the beacon image is requested from the server. The server sends the image, but not before it gathers information about the computer requesting it. The works great for checking if an email was opened, or what platform the person is on, but it doesn’t work at all for determining how long the email was open for.

One option that came to mind for checking the open time of an email was long polling.  Long polling (in this case) would use Javascript to contact the server every X seconds after the email was loaded.  Using those requests, it’d be trivial to find out how long it was open for.  Unfortunately, most (if not all) email clients don’t allow the execution of Javascript within emails, so that idea was completely sank.  The only option I had left was to use the beacon image to somehow determine open time.

The only option I could think of for using the image beacon without any Javascript was to redirect the image back to itself.  After much trial and error, I came up with the following.

//Open the file, and send to user.
$fileName = "../img/beacon.gif";
$fp = fopen($fileName, "r");
header("Content-type: image/gif");
while(!feof($fp)) {
    //Do a redirect for the timing.?
    sleep(2);
    if(isset($_GET['clientID'])) {
    	$redirect = $_SERVER['REQUEST_URI'];
    } else {
    	$redirect = $_SERVER['REQUEST_URI'] . "?clientID=" . $clientID;
    }
    header("Location: $redirect");
}

So what’s happening in this code?  First of all, we’re opening a small GIF file that we’re going to pretend to send to the user.  The second step is to send a header for an image file to the user so that their mail client expects one to be delivered.  This step is important because if the header isn’t sent, the browser/mail client will close the connection.  After that, you make the request sleep for a few seconds (as few or as many as you want depending on how granular you want your timing data to be) and then redirect back to the same page.  The “if” statement within the while loop is there so you can identify incoming requests and log the data accordingly.

So there you have it.  If you’ve ever wondered how people track the open time of an email, it’s probably a method very similar to this.  The only caveat to this method is that it relies on the user loading images in an email.  However, if you have a large enough sample you can just take the average open time from the users that did open it and be fairly confident with that.

Note: There has been some discussion over on Stack Overflow about this article. You may find it helpful.

 

If you liked this article, then you may like:

  • PHP Dark Arts: Multi-Processing (Part 1)
  • PHP Dark Arts: Multi-Processing (Part 2)
  • PHP Dark Arts: Shared Memory Segments (IPC)
  • PHP Dark Arts: Semaphores
  • PHP Dark Arts: GUI Programming with GTK
  • PHP Dark Arts: Sockets
  • PHP Dark Arts: Daemonizing a Process
  • WordPress Development as a Team

    At my day job I’m really the only person that knows how to write WordPress plugins, so when I write one it’s usually sand-boxed on my machine where nobody can touch it. However, in a side endeavor I’m part of we have a team of 3 people developing on one plugin. As I’m the most experienced plugin developer amongst our team, I was tasked with coming up with a development style and plugin architecture that would work for us.

    Development Style

    Everyone will be running a local copy of WordPress and making their changes to the plugin locally. The plugin itself will be under version control using Git, and developers will push/pull changes from either a self-hosted Git server or Git Hub. Database schema will be tracked in a file called schema.sql. When someone makes a change to the schema, it goes into that file at the bottom with a comment about why the schema changed. We’ll being jQuery as our Javascript framework of choice, and we’ll be writing all of our Javascript in CoffeeScript (see my previous entries).

    Plugin Architecture

    The more difficult aspect of developing this plugin as a team is the sheer size of the plugin. Realistically this could probably be split into about 6 different plugins by functionality, but we want to keep everything together in one tidy package. To illustrate the architecture, I made a quick drawing.

    The first layer of the plugin is essentially a wrapper. It initializes the ORM that we are using to access the database (we are using a separate database for this plugin’s data), and includes the wrapper class. The wrapper class is where developers drop their sub-plugin include file and instantiate it’s main object. For instance, for each sub plugin there will probably be two classes instantiated in the wrapper. One being admin related functionality, and the other being for front-end display functionality. My thinking with this architecture was that we could all work on separate sub-plugins without crossing paths too frequently. This also allows us to separate the different functionality areas of the plugin in a logical manner. The other benefit to architecting the plugin like this is that it will be very easy to port to a different architecture in the future. I’m well aware that WordPress probably isn’t the best tool for the job, but it is the best tool for the team with the deadline that we have.

    Thoughts

    While thinking about WordPress Plugin Architecture, I cruised the source code of a lot of plugins and it seems that everyone goes about it in a different way. If you’ve ever developed a large-scale plugin with a team, how did you go about doing it? Did you run in to any problems that you didn’t foresee at the beginning of the process?

    Installing Memcache on MAMP

    For the better part of 2 hours I tried and failed to get the Memcache extension installed on MAMP.  I tried following several guides, but everything fell flat on it’s face about 75% of the way through.  I eventually figured it out, and I wanted to share it so that other people don’t have to go through the pain and suffering that I did.  It turns out to be surprisingly easy, but YMMV.

    Step 1: Install XCode

    Step 2: Make the MAMP PHP binary files executable

    sudo chmod +xrw /Applications/MAMP/bin/php5.3/bin/p*

    Step 3: Get the Memcache extension source

    cd ~
    wget http://pecl.php.net/get/memcache-2.2.5.tgz
    tar -zxvf memcache-2.2.5.tgz
    cd memcache-2.2.5

    Step 4: PHPize the Memcache extension files

    /Applications/MAMP/bin/php5.3/bin/phpize

    Step 5: Compile the Memcache extension

    ./configure
    make

    Step 6: Add the extension to the PHP.ini file

    Add the following to the end of your PHP 5.3 ini file via the MAMP file menu.

    extension=memcache.so

    Step 7: Copy the memcache extension to the PHP extension folder

    cp modules/memcache.so /Applications/MAMP/bin/php5.3/lib/php/extensions/no-debug-non-zts-[yourtimestamp]/

    The “[yourtimestamp]” varies per installation, but you should just be able to tab complete that part.

    PHP Alternative Syntax

    Did you know that PHP has an alternative syntax structure?  Up until about two years ago, I didn’t either.  It wasn’t until I started poking around in the WordPress core that I saw it.  Intrigued, I popped over to PHP.net and read an entry on it.  In a nutshell, the alternative syntax can go far in making your PHP code much easier to read.  The control structures if, while, for, foreach, and switch can all be expressed in the alternative syntax form.  In general, I prefer to use the alternative syntax when mixing PHP in with HTML, and the standard syntax when writing pure PHP.

    If Example

    // This....
    if($myString == "foo"):
        echo "bar";
    else:
        echo "no-foo-bar";
    endif;
     
    //...is equal to this.
    if($myString == "food") {
        echo "bar";
    } else {
        echo "no-foo-bar";
    }

    ForEach Example

    $names = array("bob", "tom", "john");
     
    //This....
    foreach($names as $name):
        echo "Your name is: {$name}";
    endforeach;
     
    //...is equal to this.
    foreach($names as $name) {
        echo "Your name is: {$name}";
    }

    Resources

    If you’re looking for more resources on PHP’s alternative syntax, check out the documentation here, or the WordPress source code for examples.