When developing a plugin should the functions be grouped together into a Class to avoid namespace conflicts?
Does using classes create performance overheads for PHP?
If there is a performance hit, should function names just be pre-fixed instead?
Yes, but that's only one of the minor arguments. In-fact that's not the "true" nature of a class in OOAD.
No, not notably. Bad design and/or bad written code or pre-mature optimisation creates far more performance problems than actual language features.
As written, there is no performance hit. Bad written code will be more of a performance hit than good written code that has some more lines of code but does not force you to do bad things.
You can make differently use of classes for plugins. You can just use them to have some kind of namespace and use them "just" for global functions. The most direct form of that are static class functions, the following code-example shows both, first global functions, then global static class functions:
This is just a little example showing that you need to type more for the single hook. Additionally it shows how the namespacing works: You can easier replace the single class name to rename all static functions and then search and replace
And this example shows as well: Namespacing is fine, but with worpdress, the namespacing stops with using hooks: The callback function is hardencoded, hence the benefit in namespacing using the class (one place for the base-name, the classname) does not help when you intervene your code with wordpress for the hook names.
The real benefit starts with using actual class instances and non-static functions. This has the benefit that you can start to make use of OO principles and you can streamline your code. Static class functions are more a problem than a solution infact.
Then it's more than just syntactic sugar.
Key point is: Do something that helps you to write the code you can easily deal with and maintain. Don't over-rate performance, that's a common mistake. More important is that you write code that is easy to read and understand, that just does what you need. Maybe this question and answer is helpful for a bigger picture in this context: Multiple Custom Metabox Help.
One common approach I have even with smaller plugins is making use of a static helper function to instantiate the plugin and the rest resides within the plugin instance then. This helps to encapsulate the main plugin logic and it benefits from namespacing with the hooks as well that private members can be re-used between hooks which is not possible with standard global functions. The following code-example shows the pattern:
This is a common pattern I use for the base plugin file. The plugin class on the one hand represents the plugin to wordpress and on the other hand it allows to start to use object oriented paradigms for the own code which can even be completely object oriented (but need not be). It's kind of a controller, interfacing with the whole wordpress API as the request(s).
As the example shows, an instance of the plugin will be created. This allows you to make use of known commons like a Constructor Docs (
At the time the hook is registered, this plugin object already benefits from it's design: You've ceased to hard-code the actual hook function against the concrete plugin classname. That's possible because of the binding of the class to the object instance for the callback. Sounds complicated, just saying:
This pattern allows to easier interface with wordpress: the injection is reduced to the names of the hooks and which data they provide. You can then start to implement directly into this plugin class or to refactor your implementation against it, so to only put code into the plugin class that is the bare minimum to define your plugins interface against wordpress, but keep the general logic aside of worpdress. This is where the fun starts and most probably that what each plugin author want's to achieve in the long run.
So don't program with worpdress but against it. As worpdress is quite flexible, there is no common or easy to describe interface to program against. A base plugin class can take up this role, allowing you more flexibility for your own code which will lead to easier code and a better performance.
So there is more than just a benefit for name-spacing. Best suggestion I can give is: Try yourself. There is not much you'll loose, only new things to discover.
You'll most probably notice differences after you've passed some more major updates of wordpress while keeping your plugin compatible.
Caveat: If your plugin directly integrates with wordpress to get the job done, using one or two public functions might suit you better. Take the right tool for the job.
Most of the time, if you use functions, you'll put the name of the plugin in each function name, so effectively, you'll duplicate that name a dozen times if the plugin has a dozen functions which is a bit of a drag.
With classes, you'd just have the name of the plugin in the class name likely once.
Additionally, you can use inheritance or other oo constructs to implement behaviors in a very clean manner. Here is an ex:
Classes VS function set
General: Afaik, there's no difference in "performance" between classes and function sets.
Architecture - How stuff works:
function set: In general, functions gets executed in the row you call it. So every time you call stuff, you have to write it again, if you have to call it more than once.
Class: There are different aproaches to classes. The class, that comes closest to a function set is the "factory" class (wikipedia/google). Imo it's nearly the same as a set of functions, but encapsulated in a class. But there are other "types" of classes too. You could for example write an abstract or a parent class class, that you extend with a child class. In a real world example: Let's say you got a class that builds some static text fields. In your
If you write your classes wisely, then you'll have a minor advantage in performance. But you'll have a well organized structure to work on. So far nothing spectacular. But if you consider the following "split" use cases for classes and functions in a plugin, then you'll get my final point: Class is internal, functions are API. As long as you offer API only via publicly useable functions (that then call classes or class functions), you'll be on the save side developing your plugin further. You acchieved the freedom to change the internal structure or even the possibilities of your plugin without affecting the users anytime and everywhere.
Note: Please also read the link @t310s posted in the comment to the Q.
It's a purely stylistic choice on the part of the plugin author. There is no real difference in terms of speed.
Classes don't usually offer any benefits in terms of performance, but they very rarely have any negative effects either. Their real benefit is in making the code clearer and avoiding namespace conflicts.