How to use the static keyword with WordPress

This site has a lot of object-oriented programming articles. Most of them focus on solving WordPress problems using object-oriented programming. This is great when you’re comfortable with object-oriented programming.

But most WordPress developers aren’t that comfortable with it. (You’d think there’d be a book on that or something.) It’s one thing to read about basic concepts like encapsulation and inheritance. It’s another to put them in practice. There are a lot of obstacles that you have to overcome.

One of these obstacles is the proper use of the static keyword. Static methods are a great object-oriented tool to use. But, like all good things, we can also abuse it if we’re not careful.

This happens a lot more in the WordPress development world than anywhere else. And there are good reasons for that. We’ll look at why that is and what you can do about it.

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Mastering the use of PHP conditionals

No set of control structures is more pervasive in programming than if, elseif and else. With a few exceptions, you’ll use at least one per function or method that you write. There’s just no way around it.

But conditionals (that’s what we call these control structures) fit in the “easy to learn, hard to master” category. In fact, they’re so easy to use that you can develop some bad habits around them. (This is also a problem with loops.) This can lead to code that’s complex and hard to read or even test.

That said, it’s possible to develop good programming habits with conditionals. This is what this article will try to help you with. We’ll go over some programming techniques that can help make conditionals more manageable.

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Importing data into WordPress using the strategy pattern

Being a plugin developer isn’t easy. You have to get your plugin to work with WordPress. But more often than not, you also need it to interact with other plugins.

This interaction can take various forms. For example, you might need to modify another plugin’s behaviour using the plugin API. Or you might want to help customers migrate away from another plugin (or product) to yours.

This second scenario is the one that we’re going to look at in this article. It’s a good opportunity to introduce a new software design pattern. We call it the strategy pattern.

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Designing a class to create complex WordPress queries

Alright, it’s time to continue our journey building our awesome WP_Query_Builder class! So far, we’ve only designed it to build simple WordPress queries. But not all WordPress queries are simple or easy to model using just a cascading method.

It’s even possible that you’ve run into the limits of the WP_Query_Builder already. The class that we created then wasn’t a complete solution. It had some serious limitations if you were a WP_Query expert. You couldn’t use it to perform complex WordPress queries.

What do we mean by complex WordPress queries? We mean queries that use a complex WP_Query query parameters. At the moment, there are three of them: date_query, meta_query and tax_query.

So, for this article, we’re going to back to our WP_Query_Builder class. We’ll add support for one of these complex WP_Query query parameters. We won’t go over all three due to how complex they are. But you can apply what you’ve seen for this one query parameter to design a fluent interface for the other two.

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How to use PHP array functions instead of loops

I gave a talk at WordCamp Los Angeles 2016 on PHP array functions. This is the companion article that I wrote for it. If you’re just looking for the slides, click here.

As a WordPress or PHP developer, you use arrays all the time. They’re an essential (if not necessary) part of your developer toolbox. But that doesn’t mean that you’re using them to their full potential.

That’s because, when we work with arrays, we also tend to work with loops as well. And loops are seductive. They let you traverse an array and perform any operation that you wish on each array element.

That said, it’s easy to overuse loops. When that happens, your code becomes hard to read and to test. That’s because loops, while easy to use, can also make your code much more complex.

But, lucky for us, PHP has a wealth of array functions. They’re used by PHP experts to make their life easier and replace a lot of instances where you’d use a loop. This, in turn, makes their code simpler, easier to read and more testable.

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Designing a class to build simple WordPress queries

In a previous article, we looked at how you could create a class to manage WordPress posts. We ended creating a class who’s job it was to interact with the WordPress database. And it did that quite well!

As part of its job, our class also had to be able to query the WordPress database. To do that, we made it easier to reuse code around the WP_Query class. We achieved that by creating methods that used predefined query arguments.

But have you ever looked at the codex page for WP_Query? Holy Moley, there are a lot of query parameters in there! It’s pretty intimidating and not always easy to use in practice.

That’s the problem that we’re going to look at in this article. We’ll design a class to simplify how we build WP_Query objects. It’ll handle all the complexity around WP_Query query parameters for you. The result should be an easier way for you for you to create WordPress queries.

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Thoughts on teaching object-oriented programming with WordPress and overengineering

This site has grown a lot in the last year or so. We’ve spent a lot of time going over object-oriented solutions to WordPress problems. So much so that, we have a small library’s worth of material that you can refer to.

With any type of growth, criticism will arise. This is a good thing. I’m a big proponent of “Strong opinions, weakly held“. But this can’t happen without discussion and debate. In the long run, I always feel it leads to a better outcome. (Well, that’s as long you don’t get stuck just debating!)

Recently, there was a debate on the nature of the solutions that you’ll see on this site. They’re overengineered. I think this is a valid criticism and I wanted to share some of my thoughts on the whole thing.

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Designing a class to assemble plugin classes

Learning object-oriented programming with WordPress is a lot like embarking on an epic journey. You’ll experience some lows, some highs and some downright frustrating moments. But it’s all part of the learning process.

And, so far, we’ve done quite a bit of progress on our journey. We’ve looked at various WordPress problems. And we then solved them using a class or combination of classes.

We call this process “object-oriented design“. It’s been the focus of a lot of the articles on this site. Because of that, there’s a good chance that you’ve begun using it in your own projects. (And if you haven’t, you should try it!)

When that happens, you’ll start to notice that your project has a lot of classes. This tends to become a problem for a lot of developers. They wonder, “How do I assemble all these classes together!?” It’s not unusual for them to revert back to the standard WordPress way of doing things when that happens.

This is the problem that we’re going to explore in this article. We’ll look at how you can solve it using a dedicated class for it. To do this, we’ll start thinking about the job of the main plugin class.

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PHP strings and how to format them

Strings have always been an integral part of the programming world. We use them so much because they do something that’s almost impossible to do with other data types. They allow our code to communicate with others.

The definition of “others” is quite wide in this context. Others can be as straightforward as someone using your WordPress plugin. But it can also be more abstract like a browser reading HTML code generated by PHP. They are both a third party who interacts with strings generated by your code.

Sometimes, these strings are simple and used as is. But more often than not, these strings need to be dynamic. They need to adapt to what’s going on inside your code.

This latter one is why it’s important to have a good understanding of what you can do with strings in PHP. That’s because there are countless ways that you might want to alter a string. For example, you could have a string change based on certain conditions. Or you could insert one or more variables into it.

For this article, we’re going to focus on how you can format a string. There are a lot of built-in helper functions for strings in PHP. We’ll look at the ones that can help you achieve that goal.

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A look at the modern WordPress server stack

I gave a talk at WordCamp San Diego 2016 on the modern WordPress server stack. This is the companion article that I wrote for it. If you’re just looking for the slides, click here. It was also later republished on Smashing Magazine.

Do you remember when you could run a “fast” WordPress site with just an Apache server and PHP? Yeah, those were days! Things were a lot less complicated back then.

Now, everything has to load lightning fast! Visitors don’t have the same expectations about loading times as they used to. A slow site can have serious implications for you or your client.

As a consequence, the WordPress server stack has had to evolve over the years to keep up with this need for speed. As part of this evolution, it’s had to add a few gears to its engine. Some of the older gears have had to change as well.

The result is that today the WordPress server stack looks quite different from a few years ago. To better understand it, we’re going to explore this new stack in detail. You’ll see how the various pieces fit together to make your WordPress site fast.

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