Month: March 2016

Down memory lane, The Agile Manifesto

With the proliferation of agile term overloads and the software suites that claim to be “agile”, how do you differentiate the noise from the real thing?

Is chaos really agile?

No, certainly not. Collaboration and working software, developers at the center of enabling business change, that for me is Agile. Chaos and unmanaged change is not.

I signed the Agile Manifesto in June of 2005:
Lizet Pena de Sola is an agilite

Every time someone tells me about the next software suite that will track all my projects and solve all my problems because it will make the “process” really “agile”, I go back and read the manifesto.
If this new software suite contradicts or impedes any of the 4 cornerstones of the manifesto, that software suite, process, administrative paperwork, extra meeting, is out. Did I mention that extra excel file logging the exact same “issues” everyone knows about and the email chains?

Here are the four main points of the Agile Manifesto, focus on the ones on the left and feel free to apply these four points to any new “agile” tool that will solve all your problems overnight. The points are great to detect baloney.

I need to get rid of that switch statement. What is the Strategy Pattern?

I’m a big advocate of software maintainability and there is nothing better for that than applying well known patterns to improve the existing code. Each time I see long if..then..else constructs, or switch statements to drive logic, I think of how much better the code would be if we allow encapsulation and use one of my favorite behavioral pattern… => the Strategy Pattern.

StrategyPatternA Strategy is a plan of action designed to achieve a specific goal

This is what this pattern will do for you: “Define a family of algorithms, encapsulate each one, and make them interchangeable. Strategy lets the algorithm vary independently from clients that use it.” (Gang of Four);

Specifies a set of classes, each representing a potential behaviour. Switching between those classes changes the application behavior. (the Strategy). This behavior can be selected at runtime (using polymorphism) or design time. It captures the abstraction in an interface, bury implementation details in derived classes.

When we have a set of similar algorithms and its need to switch between them in different parts of the application. With Strategy Pattern is possible to avoid ifs and ease maintenance;

Now, how can we digest that in code, now that you got the gist of the problem and want a better solution than your case statements.

This example I’ll be showing is a pure academic exercise:

The problem to solve is given a string as an input, create a parsing algorithm(s) that given a text stream identifies if the text complies with the following patterns. Angle brackets should have an opening and closing bracket and curly brackets should also have an opening and closing bracket, no matter how many characters are in the middle. These algorithms must be tested for performance.

<<>>{}  True
<<{>>}  False
<<<>    False
<<erertjgrh>>{sgsdgf} True

Continue reading I need to get rid of that switch statement. What is the Strategy Pattern?