WordPress Modular Architecture

WordPress is a modular web content management platform, meaning that when you install WordPress on a web server, you get a basic set of built-in (or “core”) functionality that every other WordPress user gets, even users of the WordPress.com hosted software. Where the modular part comes in is that WordPress allows anyone to extend the software to do just about anything. A plug-in usually isn’t a standalone program—it needs WordPress to do basic tasks, hence the name. Plug-in support is only included with versions of WordPress software (meaning WordPress.org and WordPress MU), as the powers that be at WordPress.com don’t allow users to install plug-ins themselves. Thousands of WordPress plug-ins have been written, with more coming every day. A scan through the Most Popular Plugins page in the WordPress Plugin Directory at http://wordpress.org/extend/plugins/browse/popular shows the variety of options you have. There are plugins that add functionality to your Administration page, help you generate traffic through search engine optimization, allow visitors to share your content through social bookmarking, and connect with you through your social networks. You can use plug-ins to build forums for visitors to interact with you, check your site for broken links, and back up your database. There are even plug-ins to add icons to your posts, or links, or comments, or just about any element on your blog. Which ones you include on your blog is completely up to you. Plug-ins make your blog stand out and help to define the kinds of things you care about in your blog. Because they are completely optional bits of code and functionality, you can choose exactly which plug-ins you want on your blog, and where existing functionality is good enough. In this chapter, we help you sort out the differences between plug-ins and widgets, find appropriate plug-ins for your site, and give you a sense of the variety of plug-ins out there. There are plenty of “essential WordPress plug-ins” lists on the Web, but what is essential for one WordPress user might be thoroughly useless for another. The people who decide what’s really essential are the WordPress development team, as many bits of plug-in code have been incorporated into the WordPress core. Meanwhile, open source software generally, and WordPress in particular, is about having choices. Have fun with your choices.

Defining a Plug-In

WordPress is not alone when it comes to allowing plug-ins to coexist with its own software. The famous iPhone App Store is nothing but a plug-in repository for the iPhone (and iPod Touch) soft- ware. When you install the Mozilla Firefox web browser, you are soon invited to install a batch of recommended extensions to the browser that enhance your experience or give you added functionality. To clear up one possible area of confusion: Plug-ins and widgets have a fairly organic connection, but they are not the same thing. Widgets are usually part of a theme’s sidebar or footer, and, like plug-ins, add functionality to a standard WordPress blog page. All of the following statements are true:

· Plug-ins can create widgets. Widgets cannot create plug-ins.

· Widgets are always components of themes. Plug-ins can be a theme component, but can also work directly with WordPress core.

· Widgets can be used on WordPress.com. Plug-ins cannot be used directly, but it’s often easy for a developer to convert a plug-in into a widget that does the same thing.

· Widgets are always items displayed on your page; plugins can appear in the Administration page, on one or more pages, or work completely behind the scenes.

One final way to think of the differences between widgets and plug-ins: Widgets are always about enhancing the visitor’s experience on your site; that’s why they are always visible. Plug-ins can focus on user experience, but also make things easier on you as the blogger and administrator of your site.

Finding Plug-Ins

The process of finding worthwhile plug-ins for your blog is very similar to finding the right theme for your blog, but the thinking that goes into your choice can be radically different. Themes are mostly about presenting a face to the world; selecting a theme is the way to define a look for your online presence. Plug-ins are all about functionality and automation; selecting a plug-in or set of plug-ins goes a long way to defining what you want to do with your online presence. Basically, you need to decide how much time and energy you want to spend on your blog site. What blog-related tasks do you enjoy doing, and what would you rather not think about? Do you want to have control over every aspect of your site, tweaking settings every day until the system works exactly the way you want it? Do you prefer having a system that takes care of all the administrative tasks behind the scenes, making it as easy as possible for you focus on creating blog content? What is the next cool thing you can add to make visitors become readers, and readers become a community? When you have answers to these questions, you can start looking for plug-ins to help you realize that part of the vision.In this section, we’ll walk through the process of finding the plug-ins you need, once you’ve decided what to look for.

Finding and Installing Plug-Ins from the Directory

As with themes, the easiest way to find and install WordPress plug-ins is through the Add New page in the Administration page Plug-ins section of your WordPress blog. This page integrates the WordPress Plugin Directory into your WordPress installation. As of this writing, the Plugin Directory hosts over 7,000 plugins. From the Dashboard, click Plug-ins and then click Add New. The screen offers many ways of discovering plug-ins (as shown in Figure 13.1):

· Standard search, by Term (keyword), Author, or Tag

· Click an item in the tag cloud below the Search window to see plug-ins tagged with the term. As with the Tag Cloud sidebar widget, the bigger the text, the more frequent the appearance. Thus, in Figure 13.2, the Post and Widget tags have the most available plug-ins.

· Browse among the Featured, Popular, Newest, and Recently Updated plug-ins in the directory by using the links at the top of the screen.

Unlike the Free Themes Directory, the Featured and Popular plug-ins do not track each other quite so consistently. This, perhaps, reflects a possible divide between the development team and the users over which plug-ins are the most valuable, but more likely that users better know what they want. Defining a valuable theme is a much more subjective process than looking for software that can help you reach your goals.

To view more information about a plug-in, click the name link in the directory. This brings you to the plug-in page, either on the developer’s site or on the directory itself, Click items on the link bar (Installation, FAQ, Screenshots, Other Notes, and Stats) to check out even more information. Return to the Administration page and click Install for any plug-in you want on your site. Another Description pop-up page opens. Look this over, and click Install Now. WordPress downloads the plug-in archive and unzips it to the /wordpress/wp-content/plugins directory. Click Activate Plug-in to turn on the plug-in to complete the process.

Plug-in Compatibility

One piece of information you will want to check before installing any plug-in—inside or outside of the directory—is the Requires WordPress version number (the first version of WordPress your plugin supports) and the Compatible Up To version number (the most recent version a plug-in has been tested with; ideally this would be the current stable version, or even the beta of the next version). New versions of WordPress, which appear quite frequently, can suddenly break any plug-in. With thousands of existing plug-ins, the WordPress team can’t check every one to see which plugins are headed for doomsday. That testing falls to the plug-in developers. Most plug-ins work fine moving forward, but new WordPress version releases are indeed a nightmare time for plug-in developers. Plug-ins that haven’t been tested in awhile might have been abandoned as well. If the last compatible version listed is WordPress 2.0, you might want to look elsewhere.

Finding Free Plug-Ins Outside the Directory

Compared with the similar process with themes, it seems to be a little harder to find free plug-ins that are not in the WordPress Plugin Directory. Although the Google search for “free WordPress plug-ins” generates even more hits than “free WordPress themes” (87 million versus 49 million), nearly all the top 50 matches point directly to the Plugin Directory, or to developers already in the

Plugin Directory.

So how do you learn about the best plug-ins? Again, look to the community for answers:

· The Weblog Tools Collection highlighted in Chapter 12, “The WordPress Toolkit: Themes,” does plug-in reviews twice a week.

· Angelo Mandato does the consistently interesting WordPress Plugins Podcast, where he reviews one plug-in at a time. He also reports from conferences and interviews plug-in developers to learn more about their recent work and their craft. Listen and subscribe at www.pluginspodcast.com.

· The WordPress Plugin Database at http://wp-plugins.net is a promising idea, if somewhat neglected as a project.

Finding Premium Plug-Ins

One of the bigger controversies in the WordPress community is over premium plug-ins. Developers accuse Matt Mullenweg and the WordPress development team of drawing a philosophical/ideological line in the sand over anything other than free-of-charge and free/open source plug-ins piggybacking on the WordPress core. This seems ironic to some, as Automattic is itself for profit. The battle heated up when the Commercial Theme repository was built and made available. Plug-in developers who sell their work for money have demanded equal treatment, but as of this writing, it hasn’t happened. Meanwhile, premium plug-ins are out there. Some are developed by the same shops that sell premium themes. Others can be found through common search engines. And some folks have put together lists of quality premium plug-ins, including Kevin Eklund’s “Ultimate Review List of Best Premium WordPress Plugins” at http://tomuse.com/premium-wp-plugins-review. In addition, the WPHacks blog occasionally reviews premium plug-ins. Find these reviews at http://wphacks.com/tag/premium-plugins.

Manually Installing and Activating Plug-Ins

When you come across a plug-in you want to try out that is not in the directory, the process of installation and activation is very similar to installing themes.

Downloading New Plug-Ins

When you find your plug-in, go to the developer’s website and follow their process for downloading the plug-in. For premium plug-ins, there will likely be a financial transaction first.

1. Download the *.zip archive to your computer. In most cases, this means clicking the Download link, and saving the archive anywhere on your computer (but most often in the Downloads folder).

2. Use a decompression program like PKZIP, StuffIt, or Ark to extract (unzip) the archive on your computer. In nearly all cases, this creates a new folder with the name of the plug-in.

3. Use an FTP program to connect to your web server (assuming you’re not hosting your blog on your own computer), and transfer the entire <plugin-name> folder to /wordpress/wp-content/plugins in your WordPress installation folder.

Testing Your New Plug-In

This is the place and time where having a WordPress installation on your own computer can be very useful. Plug-ins by definition should work without hassle with the current version of WordPress core, but whether they work with every other plug-in installed on your server is another matter entirely. Your test server does not have to be a duplicate of your production setup. Content isn’t especially important; that is, you don’t have to have all your posts up there, but there should be at least one post, preferably with an image attached. Your existing theme, set up identically to the production server, should also be loaded. If you do have a test server set up, try adding your new plug-in to the setup. Run all the existing plug-ins one at a time for standard operation, and then change a setting or two to check for unwanted effects. If the plug-in passes, go ahead and upload the plug-in to the production server at your web host.

Selection and Activation

When you have your plug-in downloaded and installed into the WordPress/wp-content/plugins directory.

To turn on your new plug-in, click the Activate link. Some plug-ins have settings. If you don’t see a Settings link on the Manage Plugins page, go to the main Settings page; click Settings from the left navigation pane. Your plug-in should have a link listed there somewhere. When setup is complete, give your plug-in a test spin. If all is well, tell your visitors all about what you’ve added and how well it works. If you’re so inclined, go back to the WordPress Plugin Directory and rate the plug-in, too.

Managing and Updating Plug-Ins

All software changes sooner or later, and it’s true of WordPress plug-ins, too. Bugs get fixed; new functionality is added. As with WordPress core itself, the Plugin Directory tracks updates for the plug-ins stored there. When a plug-in is updated, you should see news of the fact on your Manage Plugins page, just as when there’s a WordPress update. There’s also notification in the navigation pane. As always, before making any substantive change to your WordPress installation, back up your database. To install the update, just click the Upgrade link on the page. WordPress downloads the upgrade, extracts the new plugin code, and reactivates the plug-in. The upgrader then displays the results, as in Figure 13.4.

Prior to version 2.9, if more than one plug-in had an update, you had to run each update separately. No more! When you see that more than one plug-in has an update, go to Tools, Upgrade from the navigation bar. Check the Select All box (as in Figure 13.5), then click Upgrade Plugins. You still have the option to update each plug-in separately, if you want to hear more about each update before committing.

When the upgrade is complete, retest the plugin using the procedures we outlined in the earlier section, “Testing Your New Plug-in.”

Some “Essential” Plug-Ins

As noted at the beginning of the chapter, there really isn’t any plug-in that is an absolute must-have. Everyone’s different. Although plug-ins that find their way into WordPress core might be viewed by at least some as essential for everyone, you aren’t even required to use every tool WordPress offers you! Nonetheless, there are some very useful and popular plug-ins that might serve you well. We’ll use the rest of this chapter to highlight them for you.

Basic WordPress Plug-Ins: Akismet and Hello Dolly

Two plug-ins are installed with WordPress, but are not activated. One of them, Akismet, is as near to essential as you can get, whereas the other, Hello Dolly, is yet another signpost of the playfulness of the WordPress project founder. Akismet protects you and your legitimate visitors from the scourge of the blogosphere: comment spam. Spammers use the commenting tools meant to make blogs interactive to deliver traditional spam (that is, offers to sell assorted products of dubious origin and repute) or links to “phishing” sites designed to steal visitors’ identities (or just their money). Simply put, if you are going to allow people to comment on your blog postings, you need to install the Akismet plug-in. Tragically, there’s no way around this as long as spammers roam the Web looking for email addresses and other critical private information. Hello Dolly can be thought of as the proof of concept for the WordPress plug-in ecosystem. When activated, it delivers a simple message to the Administration page each time you access it.

Installing Akismet

Running Akismet is a little complicated the first time out. You must first obtain an API key from WordPress.com. Because Akismet works by running comments through Akismet’s servers, using the single key allows Automattic to keep track of how many users it has, and makes sure they have enough servers to keep up with demand.

1. Click the Activate link under Akismet. A message box appears, advising you that you have to enter your WordPress.com API key before Akismet will work.

2. Click the link in the message box to travel to WordPress.com. If you don’t have an account yet, register for an account. Remember, just because you have an account at WordPress.com, you don’t have to use it for a blog. You just need the API key. See Chapter 3, “Creating Your Blog’s Look,” on how to set up your account. WordPress.com will then email your API key.

3. If you have an account already, log in. Scroll down the navigation pane and click Users. Click Your Profile. At the top of the profile screen is your API key, the blotted out section of Figure 13.6. Select that bit of code and copy it to the Clipboard.

4. Return to your WordPress.org Manage Plugins page. Click Akismet Configuration.

5. Paste your API key into the WordPress.com API Key edit box, then click Update Options to save the configuration.

Running Akismet

We described the basic operation of Akismet at WordPress.com. The application doesn’t run any different in the self-hosted, WordPress.org implementation. Akismet will report on the state of the spam queue directly from your Dashboard. Check your spam queue regularly to make sure no real comments are accidentally shuffled into spam. This does happen, though rarely enough that you are much more likely to thank your lucky stars for such an effective application, rather than curse the fools at Automattic for foisting such vile code on a trusting populace.

Installing Hello Dolly

Hello Dolly is as simple a plug-in as you can get; the Mullenweg equivalent to Hello World. It spits out a quote from the Broadway (and Hollywood) musical Hello Dolly! in the upper-right corner of your Administration page whenever you look at it. As Matt describes it: “This is not just a plugin, it symbolizes the hope and enthusiasm of an entire generation summed up in two words sung most famously by Louis Armstrong.” So go ahead, put it on; it won’t hurt anything. These two starter plug-ins are just the tip of the iceberg for the WordPress plug-in ecosystem. The rest of this chapter will highlight just some of the variety of tools available to help you run your blog.

Administration and Security

These items help both with the drudgery of site administration and keeping your blog safe.

· GD Press Tools—This is a great plug-n, especially if you tend to be obsessive about tweaking your site and database. Press Tools (the GD comes from the developer, called Golden Dragon) delivers all the information about your WordPress installation you could ever want, and helps you make some adjustments as well.

The first thing you’ll notice when you install Press Tools is your Dashboard footer now has information on how much memory you’re using for WordPress, along with a running total of database queries made and the page load speed. A Press Tools widget also appears on the Dashboard page with “additional options.” Click the GD Press Tools tab in the left column navigation to view 10 pages of data about your installation (see Figure 13.7). Press Tools is not just about information. Among the nicer interactive settings include: On the Posts page, you can close Comments on posts older than a specified date. Change your existing username on the Administration page. Optimize and backup your database on the Database page. A premium version supplies even more information and options.

· Update Notifier—WordPress makes it abundantly clear when the core application has been updated on the Dashboard every time you log in to WordPress. This is a good thing, because often minor releases come out after a security issue has been found in the wild, and a fix is ready. What happens, though, if you use a third-party editor, or email your posts into WordPress, and just don’t visit the site every day? Update Notifier can help. This plug-in checks the WordPress update servers every day and emails you when it’s time to update. You’re still responsible for applying the update, but you can’t say you weren’t notified.

· File Monitor—As with Update Notifier, this plug-in keeps an eye on the files in your WordPress installation, and emails you when one or more files change. This email represents good news after you’ve applied some updates, and less than happy news when you haven’t made any changes. Once again, File Monitor just tells you what’s changed. You’re responsible for deciding what to do next. The Troubleshooting Note at the end of the chapter should help.

· WP Database Backup—You’ve heard it a million times. If you value your data, back it up regularly. When you’re a blogger, your readers depend on having access to your posts. Those who have linked to your blog posts expect those links to work, too. When you remember that everything in your blog is stored in the database, you’ll know to make a point of backing up that data- base regularly. This tool inserts a Backup page in the Tools menu (see Figure 13.8).

On this page, you can specify particular database tables (besides the defaults) to be backed up,choose what to do with the completed backup (store in a location on the server, download to your computer, or email to an address of your choice), and schedule your backups.

· WordPress Exploit Scanner—Protect yourself against hacker attacks by running this scanner periodically. Click the Dashboard widget in the navigation bar, then click Exploit Scanner. Click the Run the Scan button. The plug-in searches for hidden links, malicious JavaScript and other possible exploit code, and it provides a fairly detailed report on the same page when the check is complete. You can adjust the default items to scan, but unless you have reason to believe something’s wrong and know where the problem might lie, we recommend leaving the defaults alone.

Statistics

Your web hosting company will offer you a detailed statistics package that identifies how many times your pages are being visited by a browser, and an educated guess about who is visiting. These statistics packages are designed to report on static web sites. As a blogger interested in making connections with people, you need a different set of statistics. We’ve already talked about the WordPress.com Stats plug-in, but there are some other popular and effective plug-ins to give you deeper insight into your audience:

· Google Analytics for WordPress—Joost de Valk (also known as Yoast) is one of the bright lights of the WordPress community. This plug-in connects your blog to your Google Analytics account (after you share your account ID) and tracks downloads, AdSense clicks, image searches, and quite a few other relevant statistics.

· Woopra Analytics—This plug-in provides yet another free set of analysis tools. Sign up for an account at woopra.com (the plug-in provides a link in the Settings area), and add a bit of JavaScript code to your theme’s footer to allow Woopra to track your traffic. Access the analytic report through their desktop client, downloaded from their site.

· Search Meter—Ever wonder what your visitors search for when they come to your blog? This plug-in tracks what people type into your search box and what kind of results they get, includ- ing terms that generated no results. Go to Settings, then Search Meter to set up your options. Go to Dashboard, then Search Meter to receive your search report.

· bSuite—This plug-in provides another way to find out what your audience wants. This plug-in aims to “help surface interesting and relevant posts,” among other things. Go to Settings, then bSuite to adjust the default settings. Go to Dashboard, then bStat Reports to view Quick Stats on daily page loads.

Comments

For some people, the ability to interact with readers through commenting is at the heart of the blogging experience. WordPress offers a basic commenting system out of the box, but that may not be enough for you. One or more of these plug-ins can trick out your commenting area more to your liking.·

IntenseDebate—This commenting system is now owned by Automattic. This system helps you organize discussions by threading conversations. Commenters can develop a reputation across blogs through comment and user ratings. A nice feature for the site owner (you) is the ability to respond to comments via email. Create a free account at www.IntenseDebate.com, then install and activate the plug-in.

· Disqus—This is the other prominent commenting system, presumably if you want your com- menting system to be less intense. Disqus (pronounced “discuss”) is about connecting traditional blog commenting with other social networking tools. If your audience can tweet with the best of them, this system may be what you need. Commenters can log in with their Facebook or Twitter accounts, along with OpenID (an identity management system supported by WordPress and IntenseDebate). Install the plug-in, sign up and log in at www.Disqus.com, and you’re ready to go.

· GD Star Rating—Using this plug-in, you can let your readers rate pretty much any element on your site with either stars or thumbs up or down: your posts and pages, along with other com- ments. Take the ratings statistics and post them in a sidebar. These developers even offer a sup- port forum, so whatever problems you might encounter can be dealt with in a prompt and reasonable manner. This is another plug-in from the same developer as GD Press Tools, listed in the Administration section.

· Subscribe to Comments—Using this plug-in, you can generate a separate RSS feed for your com- ment stream and allow commenters to get an email when someone else replies in the thread. When someone comments on the standard form, the plug-in adds the option to subscribe. Use Settings, Subscribe to Comments in the Administration page to customize your messages.

· Ajax Edit Comments—Ever said something in a comment or a blog that you wanted to take back? When you’re the blogger, WordPress lets you edit posts and comments at all times, but what about the other visitors? In most cases, those words will haunt them to eternity or at least until the final crash of the last web server on earth—unless, of course, you have installed this plug-in. Ajax Edit Comments lets your commenter edit her own words for a period of time that you (or your admin) can set.

Advertising/Search Engine Optimization

While you may not be into blogging strictly for the income potential, there’s certainly no harm in picking up some of the loose change available for bloggers. These tools are about maximizing your exposure and visibility on the web, and turning at least some of that fame or notoriety into supplements to your bank account.

· Google XML Sitemaps—Search engines all love highly organized sites. This plug-in generates a new sitemap every time you update your blog, keeping the engines notified that there’s something new to index. Generate the sitemap and define the search engines you want to notify in Settings, XML-Sitemap.

· All in One SEO Pak—This is the most popular WordPress plug-in ever. This set-and-forget tool aims to raise your blog’s profile to get you more visitors and, in turn, a bigger audience. Look for All in One SEO in the Settings area of the navigation bar to set things up.

· SEO No Duplicate—Some folks try to game the search engine system by making sure certain phrases appear early and often within their sites. If your blog happens to focus on medical advertising, and every post mentions one drug after another, you could find yourself bounced from search engines entirely. To avoid this, you want to use the Canonical property in your head tag to define your topics. This simple plug-in helps you easily tell the search engine bots the preferred version of a page.

· Easy AdSense—Once you have that big audience, Google AdSense could just make your blog economically self-sustaining. This plug-in wants to simplify adding Google ads to your site.

Links

All three of these plug-ins allow your visitors to flag posts on social bookmarking and networking sites:

· AddToAny—This plug-in is not kidding when it calls itself AddToAny. Visitors can share your post via email, social bookmarking sites, and more social sites than you’re likely to have ever heard of. They also have a Share button for WordPress.com users that functions like a book- marklet.

· Sociable—Thousands of folks download this plug-in every day to put a colorful little ribbon to“share or bookmark this post.” It is configurable for dozens of sites.

· ShareThis—The familiar green button doesn’t paste a million little logos on your page like the others, but instead takes people to the ShareThis site, where they can select the service(s) they want to post to.

Multimedia

These plug-ins simplify and enhance audio/visual aspects of your blog.

· Page Flip Image Gallery—Create an Image Gallery that looks more like a presentation, with

Page Flip effects. This plug-in is great for photoblogs that document events.

· Viper’s Video Quicktags—This plug-in is so good and so useful it was incorporated into WordPress v2.9. Consider Video Quicktags as one of the links plug-ins in reverse. Want to include video from YouTube, Vimeo, Blip.tv, or some other popular site in your post? This plug-in relieves you of the obligation to copy an entire block of HTML to embed the player on your site.  Just click a site button and paste the URL in the edit box to display the clip.

· WPAudio MP3 Player—If you’re disappointed with the standard Flash-based WordPress audio player, you might want to upgrade to this relatively new player. It claims better sound, performance, and continuing development.

· Podcasting—If you prefer to talk into a microphone than write your blog, podcasting is the way to go. This plug-in helps get your podcast distributed through podcast network sites. Post the URL of your podcast file, and this plug-in will wrap it in an iTunes-compatible feed. Plus, it will slap an appropriate audio or video player on your site for your visitors to use.

Social Networks

Some people think traditional blogging is being displaced by the 140-character microblog, like Twitter. These plugins show that the two formats aren’t necessarily at odds; use them to link your blog to various social networks.

· WP FollowMe—This is a simple plug-in that allows visitors to connect with your Twitter account. We’ll take a closer look at this plug-in in Chapter 15, “PHP Basics: Themes and Plug-Ins.”

· Lifestream—Consolidate your social networking and microblogging activity in WordPress with

this plug-in. Lifestream collects RSS feeds from all of your networks and puts them in one place.

· WP Greet Box—You’ve probably been to a site that welcomed you with a warm greeting, “Hi, looks like you came here from Google. Hope you found what you were looking for. If you like this post, maybe you’d like to subscribe to my RSS feed.” Although the more paranoid might wonder how you knew where they came from, many more people probably recognize the warm fuzzy feeling you were trying to generate. This plug-in will generate just such a message.

· Twitter Tools—This is Alex King’s umbrella for an entire ecosystem of microblogging connections to WordPress. Twitter Tools by itself “allows you to pull your tweets into your blog (as posts and digests) and create new tweets on blog posts and from within WordPress.” If you’re big into the bird (even if you’re not so crazy about the Fail Whale), check this out, and then search the directory for “twitter tools” to discover what other developers have done with this framework.

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