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This not only boosts the readability of our code, but also increases the maintainability of our applications and libraries (gems).įrom the readability perspective, it’s much easier to read: rescue ValidationError => e For example, we can decide which exceptions to handle in a more natural way. Having an extensible, comprehensive exceptions package for our application makes handling these application-specific situations much easier. For example: class ApplicationError < StandardError endĬlass ValidationError < ApplicationError endĬlass RequiredFieldError < ValidationError endĬlass UniqueFieldError < ValidationError endĬlass ResponseError < ApplicationError endĬlass BadRequestError < ResponseError endĬlass UnauthorizedError < ResponseError end Investing some time in logically structuring this hierarchy can be extremely beneficial. To preserve the readability, maintainability, and extensibility of our code, it’s a good idea to create our own subtree of application-specific exceptions that extend the base exception class. Most languages come with a variety of exception classes, organized in an inheritance hierarchy, like any other OOP class. Always create your own ApplicationError hierarchy Note: We will present examples from Ruby, but all of the constructs demonstrated here have equivalents in the most common OOP languages.

With that said, let’s dive into these practices and see how each of them affects those three measures.

These elements are the main factors of what we might call cleanliness or quality, which is not a direct measure itself, but instead is the combined effect of the previous points, as demonstrated in this comic: This is critical for efficiently discovering bugs and untested code.

#Simple comic multiple validation errors code#

readability: Allows us to easily read the code and discover it’s purpose without spending too much time digging.Extensibility provides flexibility, and enables a high level of reusability for our code base. extensibility: Allows us to easily add to our code base, implementing new or changed requirements without breaking existing functionality.maintainability: Allows us to easily find and fix new bugs, without the fear of breaking current functionality, introducing further bugs, or having to abandon the code altogether due to increased complexity over time.Rather, we should learn the art of handling exceptions gracefully, making them harmonious with the rest of our code.įollowing are some recommended practices that will help you embrace exceptions and make use of them and their abilities to keep your code maintainable, extensible, and readable: As we will see, this is not necessarily true. It’s a fact of life that exceptions can’t be avoided, but we are often taught they must be dealt with swiftly and decisively. The stigma surrounding exceptions often makes programmers feel at a loss. Likewise, misusing them can actually do a lot of harm to your code base, making it brittle, or obfuscating the cause of errors. But overusing these patterns will cause code smells, and won’t necessarily be beneficial. There is nothing wrong with the previous code. For example, Ruby provides for the following typical pattern: begin A robust exception handling system is built into most languages, nowadays. With the rise of object-oriented programming (OOP), exception support has become a crucial element of modern programming languages.

#Simple comic multiple validation errors how to#

In this article, we will discuss how to manage exceptions elegantly, and use them to write clean code that is more maintainable. Rather than fearing exceptions, we should embrace them and learn how to benefit from them.

#Simple comic multiple validation errors software#

Over time, these errors, and countless others (that were, perhaps, not as dramatic, but still catastrophic for those involved) contributed to the impression that exceptions are bad.īut exceptions are a fundamental element of modern programming they exist to make our software better. History’s Worst Software Bugs contains some other bugs that could be attributed to unhandled or miss-handled exceptions. In 1996, the famous Ariane 5 rocket launch failure was attributed to an unhandled overflow exception. So, exceptions require special treatment, and an unhandled exception may cause unexpected behavior. Specialized programming language constructs or computer hardware mechanisms.

Today, Wikipedia defines exceptions as:Īnomalous or exceptional conditions requiring special processing – often changing the normal flow of program execution… Back in the days when programming was done in hardware, or via low-level programming languages, exceptions were used to alter the flow of the program, and to avoid hardware failures. Exceptions are as old as programming itself.