Comments on: Refactoring 2: Extract Method

By: sameer

sameer — Tue, 09 Jun 2009 03:57:16 +0000

We can make the code as terse as we like, but as I had created the code for one of my clients (they are developers) I choose clear expression over brevity.

By: Arne

Arne — Mon, 08 Jun 2009 20:01:39 +0000

I don’t really understand why you use a switch in this example, I wouldn’t use it in this case.
In my opinion this is more dynamic:

if (isset($forex[strtolower($currency_code)])) {
$_factor = 1 / $forex[strtolower($currency_code)];
}
else {
$_factor = 1;
}

return $_factor;

Or just in 1 line:

return isset($forex[strtolower($currency_code)]) ? 1 / $forex[strtolower($currency_code)] : 1;

You can even drop the strtolower() if you change the keys in $forex to capitals.

By: Sameer Borate’s Blog: Refactoring 3: Replace Temp with Query | Webs Developer

Mon, 08 Jun 2009 17:09:20 +0000

[...] temp variable expressions with methods. This method is often also required before you use the Extract Method [...]

By: sameer

sameer — Thu, 04 Jun 2009 05:49:51 +0000

Thanks for the encouraging thought.

By: Dave Doolin

Dave Doolin — Wed, 03 Jun 2009 19:06:17 +0000

I went to look for more articles and this was the last one!

Please write some more!

By: Dave Doolin

Dave Doolin — Wed, 03 Jun 2009 19:04:52 +0000

Thanks for writing.

I did learn something from Chris’s comment: that’s not really refactoring.

But it is restructuring, which can really help improve code readability.

Please continue this series, and don’t be afraid to make mistakes. If you’re lucky, people will actually read your articles and catch your mistakes.

Given you came up on the first page on Google, you’re doing the php community a valuable service as few others see fit to write about refactoring. Just make sure you keep it simple enough for non-experts to understand, and as accurate as you know how. Personally, I almost have to write to learn, and I make mistakes along the way. Some people harsh me for mistakes, others point them out so I can learn better.

By: Les

Les — Mon, 16 Mar 2009 17:55:53 +0000

When I came across the title of this post, I truly was expecting a post about Refactoring but this isn’t refactory (see M Fowler book), and certainly this can’t be seen as the Extract Method either.

With all the hype going about best practices, etc you’ve jumped on the bandwagon (ie keyword Refactoring) to get a higher page index which isn’t really the case, as advertised is it?

Disappointed

By: Mark

Mark — Tue, 13 Jan 2009 17:25:53 +0000

Or you could just do this:

function getConversionRateFactor($currency_code)
{
$forex = array(“gbp”=>1.2, “eur”=>.75, “usd”=>1);

switch($currency_code)
{
case “GBP” : return 1/$forex['gbp'];
case “USD” : return 1;
case “EUR” : return 1/$forex['eur'];
default : return 1;
}
}

By: Chris

Chris — Tue, 13 Jan 2009 08:43:01 +0000

In an effort to reduce the code size while being more extensible and – as I think – more readable: http://paste.mootools.net/f8819e01

Just wrapping existing code in a function is not refactoring as this changes the external behaviour (it provides a new function to “the outside” and you have to replace all occurences of currency calculation) – I know it is only an example, but this is not refactoring and more of reworking or so.

Refactoring, or the “Extract Method” you describe would be when you have a method getPrice that retrieves the conversion factor AND calculates the price based on the currency and you want to move the retrieval of the conversion factor to a new function getConversionRateFactor and call it within getPrice. This way you won’t have to change the surrounding code as getPrice still behaves the same. I know your example aims to be basic, but I think it is more clear to what it is about

By: BradGman

BradGman — Tue, 13 Jan 2009 05:16:51 +0000

Not to be confused with the “true” extract method:

extract($_POST);

Which is the utmost evil thing to leave behind for fellow developers, be warned.