Contents
How do you remove a violation of the Law of Demeter?
Lessons Learnt to Avoid Coding Violations of Law of Demeter
- Avoid getting data from invoking methods on retrieved objects from method invocations on local objects. Instead, implement method on local objects that returns the required data.
- Avoid method chain calls due to various reasons such as following.
What is the Law of Demeter trying to prevent?
What is it trying to prevent? The Law of Demeter is designed to decrease coupling and increase encapsulation. O shouldn’t know anything about what m returns, other than its existence, in order to reduce coupling to it.
Which proposed a Law of Demeter?
The law dates back to 1987 when it was first proposed by Ian Holland, who was working on the Demeter Project. The Demeter Project was the birthplace of a lot of AOP (Aspect Oriented Programming) principles.
Why is the Law of Demeter important?
The Law of Demeter principle reduces dependencies and helps build components that are loose coupled for code reuse, easier maintenance, and testability. The Law of Demeter (or the Principle of Least Knowledge) is a design guideline for developing software applications.
Why is Demeter’s law important?
Why is the law of Demeter still relevant?
The Law of Demeter can be something that keeps the track of your horny friend. It is a not-so-fresh idea, as it was published in late ’80 on Northeastern University, but it still is relevant. The Law of Demeter defines, how objects interact with each other. It says that you should talk only to the object that you directly know.
How to check Java code for law of Demeter?
Following are two most common violations for Law of Demeter. These violations can be observed in your code by using static code analysis tool such as PMB. If you are a Java developer, and you use Eclipse IDE, you could get started quickly by downloading PMB eclipse plugin.
When did Ian Holland come up with the law of Demeter?
The guideline was proposed by Ian Holland at Northeastern University towards the end of 1987, and can be succinctly summarized in each of the following ways: Each unit should have only limited knowledge about other units: only units “closely” related to the current unit. Each unit should only talk to its friends; don’t talk to strangers.