The tables have turned, and that’s why we call this an inversion of dependencies. Refuse to use Ada. In case you have but have been putting this learning off to “someday”, well, let’s make sure today is that day! However, as with many things, you don'tnec… At the heart of maintainability is carefully constructed code that is easy to read; code that is easy to dissect in order to locate the particular component relating to a given change request; code that is then easy to modify without the risk of starting a chain reaction of breakages in dependant modules. Easier to understand complex code If a programmer is writing a complex piece of code and he does not follow coding conventions, it might become even difficult for even himself to remember the logic. When I came across this the first time, the definition I was presented with was, “There should be one, and only one reason for a class to change”. The first step in creating code that is TRUE is to ensure that each class has a single, well-defined responsibility. How to Optimize PHP Laravel Web Application for High Performance? You save the line of codes, scale and extension time, creates easy understanding, minimize the chances of errors. Opposite of tight coupling is loose coupling and your code is considered as a good code when it has loosely-coupled classes. And after all that song and dance, ladies and gentlemen, we come to the point where it all falls into place and the Open-Closed Principle is revealed at work! Tight coupling means a group of classes are highly dependent on one another which you should avoid in your code. If you look at different sources describing the Single Responsibility Principle, you’ll get some variation in its definition. If we were to take this logic out of the function and put it in a separate class, we’d now have two classes, each with a single responsibility to handle. What is SQL Injection and How to Prevent in PHP Applications? Use OOPS concepts. Well, in simpler terms, that’s all this principle is saying: make sure your subclasses implement all the methods exactly as required, with the same number and type of arguments, and the same return type. Keep on working, of course! But then comes the gut-punch, the nemesis of software development — change. It might even make you regret picking up software development as a career because you thought it was all practical and no theory. Until later! One part of the reason is the company leadership (read: folks who never get it), while the other part is the complexity of the code we have to work with. The point is, we shouldn’t create our interfaces blindly. This is indeed what many developers are doing, but they’re setting themselves up for failure. Let’s look at a very common and practical example. In all tutorials covering the Repository Pattern, you’re advised to create a common interface (called a Repository) which will define the methods needed to access or manipulate data. And it’s easy to see what it does: register new users. Instead, we should create several smaller, specialized interfaces, letting classes implement those that are needed, and leaving out those that are not. “Extension” here means reuse, whether the reuse comes in the form of child classes inheriting functionality from a parent class, or other classes store instances of a class and call its methods. So, back to the million-dollar question: how do you write code that survives change? Probably the best managed WordPress cloud platform to host small to enterprise sites. Comments can serve to be invaluble for new developers coming into a project - needing to understand what's occurring in the code. Reusable code is essential to avoid duplicated effort in software development. And it also kinda tells you how to do that: classes should be open for extension and closed for modification. Sounds like it’s something to do with segregating . Yes, a quick fix would be to implement these anyway and either leave them blank or raise an exception, but if relying on such duct-tape solutions were okay for me, I wouldn’t be following the Repository Pattern in the first place! Constants should describe the value they hold, nothow that value is used. If you were thinking along these lines, trust me, you’re almost done understanding and using this principle. And you’d be right, in the sense that this principle is more or less a repetition of what we’ve discussed till now. — when none of us is going to be authoring libraries. But what this principle does mean is that we restrict the possibility of changing existing code as much as possible. The world changes, business changes, and thus, code changes — no getting around that. If changes are needed in the user registration logic, the UserService class will see to it while the controller methods don’t need to change at all. Even a single error can cause major business loss. But what it’s saying is that our code should depend on types of things, and not particular things themselves. They now want that, at the time of user registration, we log the IP address as well as add an option for a field that indicates they’ve read and understood the terms and conditions. What do you do? You might still consider creating a separate file for each of these API types and copy the existing code, modifying it slightly. While these classes can take help from each other by calling their methods, they are not allowed to know what’s going on inside the other one. The process of encapsulating your application’s business rulesinvolves truly understanding the concept and how the business expects it to work at a fundamental level. The sooner an error is found, the cheaper it is to fix it. If the next version of the MilkyWay API changes the interface, our method will stop working. Follow the Open-Closed Principle! Prefer single words for methods, interfaces, and packages. So, what does that mean? The code you write should have the following qualities. The example we finished just before this section is a great illustration: if I replace the generic IPDFGenerator type in the method argument with the specific MilkyWayPDFGenerator instance, would you expect the code to break or keep on working? As a programmer, you probably want to write elegant, maintainable, scalable, predictable code. 6 Essential Security Tips to Protect Your PHP Site from Hackers. Unless you have to work with other people’s code. This also has an added side-benefit of making the code easier to read (someone reading it for the first time won’t go, “Whoa! Writing Maintainable Code: SOLID Principles Explained in PHP (Laravel) “S” is for Single Responsibility. The business requirement changed, some new code was added (a wrapper class) and only one line of code was changed — everything else remains untouched and the entire team can go home with confidence and sleep peacefully. However, in simpler terms, it boils down to this: Each class in your codebase should have a very specific role; that is, it should be responsible for nothing more than a single goal. You’ll notice that this method does a good job of following the Single Responsibility Principle: it doesn’t attempt to walk through the HTML content passed to it and create a PDF (in fact, it doesn’t even know it’s been given HTML); instead, it passes on that responsibility to the specialized MilkyWay class, and presents whatever it gets, as a download. If you’ve read the earlier parts of this article, you might possibly feel that you understand what this principle is trying to say. I’m not going to start writing code in a totally different style from tomorrow just because some madman who once wrote a book (and is now dead) says so.”. . It helps you avoid traps that can unnecessarily complicate the code base. To be able to work effectively with such a code base, in general, the more maintainable your code is the better. To a developer, maintainable code simply means “code that is easy to modify or extend”. This “something” that I mentioned takes the form of the Service Container in the Laravel world. If you’ve worked as a professional developer for more than three days, you know our jobs are anything but creative and exciting. Free SSL, CDN, backup and a lot more with outstanding support. If even one parameter were to differ, we would unknowingly keep on building more code on top of it, and one day we will have the kind of stinking mess whose only solution would be to take it down. You might even want to create a separate interface for every method, and that will be fine too, assuming your project’s needs are that granular.). So, why are the codebases so complex that we feel like gutting ourselves? Here’s what a typical controller method looks like in actual, production-level applications: We’ve all written code like this. The answer is that the controller method that looks so harmless is actually doing a number of different things: it’s validating the incoming request, it’s handling redirects, and it’s creating new users. Let’s move on! Copy all the code from this function, make a few changes, and call it a day? And we also shouldn’t make assumptions, no matter how experienced or smart we think we are. An important lesson from Domain Driven Design is the encapsulation of Domain logic in objects. Create a similar route in the api.php file and write a JSON-driven controller function for it? All this waste because we created a method that was not closed to change. Just as bad design triggers more bad design, good design can trigger more good design. Code that is Transparent, Reasonable, Usable, and Exemplary (TRUE) not only meets today’s needs but can also be changed to meet the needs of the future. Based on 15+ years of experience, this book is my attempt to teach about the heuristics that are involved when writing loosely coupled, maintainable and readable unit tests. Yes, there are more interfaces now, and some might say there’s too much to remember or that the class declaration now is too long (or looks ugly), etc., but look at what we have gained: specialized, small-sized, self-contained interfaces that can be combined as needed and won’t get in each other’s way. Using these principles helps me write smaller pieces of… Writing good code, code that is modular and easy to maintain, isn’t that hard. This is what I meant by focus and discipline: focus in code (one thing doing one thing only) and discipline by the developer (not falling for short-term solutions). However the chances of writing maintainable code in FORTRAN are zero, and therefore following the unmaintainable coding guidelines is a lot easier. Remove Duplicate Code. . Stripped of highfalutin jargon and distilled down to its most basic form, the principle of Interface Segregation has this to say: The more numerous, more specialized interfaces there are in your application, the more modular and less weird your code will be. . When a Laravel application receives a web request, the URL is matched against the routes you’ve defined in web.php and api.php, and if there’s a match, the request data reaches the controller. Here in CustomGears we decided to gather most important best practices with Ruby on Rails, examples and definations in one place. Practice Consistency tells us to stick with our decisions throughout the project. It’s doing too many things! The business rules of the organisation should be enforced through objects that protect the invariants of the concept they are modelling. Instead of rewriting software components from scratch, a programmer can make use of an exist-ing component. Now, while we can do absolutely nothing about the former, we can do a lot about the latter. Why change?”, which is why I said earlier that if you read about this in different places, you’ll get related but somewhat different and potentially confusing definitions. Writing the same code more than once is not only wasteful when writing it the first time but even more so when trying to maintain it. This thing sounds like something straight out of an Organic Chemistry textbook. Allow me to explain. Netsparker uses the Proof-Based Scanning™ to automatically verify the identified vulnerabilities with proof of exploit, thus making it possible to scan thousands of web applications and generate actionable results within just hours. More than once I have found myself struggling with my code to fix one tiny bug or extend some feature. With that in mind, let’s look at one such technique. The problem I faced was that since I was supposed to create repositories that all implemented the IRepository interface, say the LoggingRepository, at least two of the methods in the interface, update() and delete() were of no use to me. and most importantly, adaptive to change. WTF is this MilkyWay? These guiding principles are represented by the acronym SOLID. The processing that you are doing might need to be changed. All we now need to do is write a new IPDFGenerator wrapper class for SilkyWay and change the binding in our Service Container code: Nothing else needs to change, because our application is written according to an interface (the IPDFGenerator interface) instead of a concrete class. You should do your best to avoid code duplication. For regular repositories, I’d then say class UserRepository implements IReadOnlyRepository, IWriteModifyRepository { . It’s time for something serious: if you’re like me, you’re probably wondering, “Okay, all good. Anyway, enough of it. For now, just think of it as something that can create new class instances for us. General Principles. Again, big words, but dependency injection simply means that instead of creating objects of classes yourself, you mention them in function arguments and something will create them for you automatically. For now, while we can do a lot easier do a lot with. 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principles for writing maintainable code

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