Ruby Screenshot of the Week #23: Extract Method and More Refactorings!

Last week I promised to catch up on my e-mail, but I had been missing feature work too much during the bug phase so I put it off for a week... to implement some more quickfix refactorings: Extract Method Introduce Variable Introduce Constant Here's how it works. Let's start with "Extract Method". You're looking at some code like this: You decide there's too much going on in this method, and you want to pull the middle section into its own method. Select it, and notice the lightbulb which shows up on the left: Press Alt-Enter to show the quick fix alternatives: Select Extract Method, and the IDE will pop up a dialog asking you for the name of the new method you want to extract from the selected code fragment: Press OK (or just hit Enter), and the code will mutate into the following: There's a lot to notice here. First, there's a new method, and the active selection and caret is on a comment for that method (so you can just type to replace it). The new method is added below the one you extracted code from. And the most important part about this refactoring is that the IDE figures out which variables to pass in to the method, and which variables to pass back out: a, b and d are accessed from within the fragment, so they are passed in. c is reassigned in the fragment without reading the previous value, so doesn't need to be passed in. f and h are assigned locally inside the extracted fragment, but...

Date: November, 12 2007
Url: http://blogs.sun.com/tor/entry/extract_method_introduce_variable_introduce

Others News