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Robert Basic:
Open source taught me how to work with legacy code
May 01, 2017 @ 09:36:29

In a new post to his site Robert Basic shares how some of his work on Open Source projects taught him how to better work with legacy code.

Contributing to open source projects has many benefits — you learn and you teach, you can make friends or find business partners, you might get a chance to travel. Even have a keynote at a conference, like Gary did.

Contributing to open source projects was the best decision I made in my professional career. Just because I contributed to, and blogged about Zend Framework, I ended up working and consulting for a company for four and a half years. I learned a lot during that time.

He shares some of the things that open source taught him about working with code and how it relates back to legacy code (including how to find his way around). He also tries to dispel the myth that all legacy code is bad and was "written by a bunch of code monkeys who know nothing about writing good software." He points out that, at the time the code was written, the changes may have been the best that could be done, it might be a necessary workaround or it could be an actual bug that needs fixing.

tagged: opensource legacy code opinion experience codemonkey

Link: https://robertbasic.com/blog/open-source-taught-me-how-to-work-with-legacy-code/

QaFoo Blog:
How You Can Successfully Ship New Code in a Legacy Codebase
Apr 21, 2017 @ 13:39:13

On the QaFoo blog there's a new post sharing some ideas on how you can add new code to a legacy application and ship it successfully without too much interruption to the current code.

Usually the problems software needs to solve get more complex over time. As the software itself needs to model this increased complexity it is often necessary to replace entire subsystems with more efficient or flexible solutions. Instead of starting from scratch whenever this happens (often!), a better solution is to refactor the existing code and therefore reducing the risk of losing existing business rules and knowledge.

[...] Instead of introducing a long running branch in your version control system (VCS) where you spend days and months of refactoring, you instead introduce an abstraction in your code-base and implement the branching part by selecting different implementations of this abstraction at runtime.

They then give a few examples of methods that can be use to get the new code in:

  • Replacing the Backend in a CMS
  • Rewriting a submodule without changing public API
  • Github reimplements Merge button

The final point is broken down into the process they recommend including the refactor of the current code, starting in on the new implementation and deleting the old code.

tagged: refactor ship new code legacy application tutorial

Link: https://qafoo.com/blog/101_branch_by_abstraction.html

php[architect]:
September 2016 Issue Released - Legacy Code of the Ancients
Sep 02, 2016 @ 13:29:06

php[architect] magazine has officially announced the release of their September 2016 issue: Legacy Code of the Ancients.

We don’t always have the luxury of working on greenfield projects where we can try out the latest language features, component libraries, or programming techniques. More often, we’re asked to take care of and add features to an application that just works and supports a company or organization’s objectives—like making money to pay salaries. Unless it’s a relatively new project, you are sure to run into corners of the codebase that should be modernized. The trick is to find the time and marshal your team to do so.

Articles in this month's edition include:

  • "Illuminating Legacy Applications" (Colin DeCarlo)
  • "Legacy Code Needs Love Too" (John Congdon)
  • "Building for the Internet of Things in PHP" (Adam Englander)

The usual columns are there as well including the "Education Station" and "Security Corner". You can pick up your own copy of this month's issue directly from the php[architect] site. If you just want a sample of the content, check out this month's free article - "The Modernization of Multiple Legacy Websites".

tagged: phparchitect magazine september2016 legacycode legacy issue release

Link: https://www.phparch.com/magazine/2016-2/september/

Yappa Blog:
Symfony Components in a Legacy PHP application
Jun 21, 2016 @ 12:50:13

On the Yappa Tech blog Joeri Verdeyen has written up a post covering the integration of modern Symfony components into a legacy application with a relatively simple container setup and configuration.

Symfony Components are a set of decoupled and reusable PHP libraries. They are becoming the standard foundation on which the best PHP applications are built. You can use any of these components in any of your applications independently from the Symfony Framework.

[...] The purpose of this post is to roughly describe how to implement some of the Symfony Components. I've created a set of gists to get started. You should already know how Symfony Components work in the Symfony Framework.

He starts with an example Composer configuration pulling in some of the more popular Symfony packages (like VarDumper and FormBuilder). He then includes the code to bootstrap the container instance and the services.yml he's come up with to bootstrap and integrate all of the components. The tutorial ends with examples of putting some of these components to use in resolving controllers, using the FormBuilder, using the command line and outputting errors with the VarDumper.

tagged: symfony component legacy application tutorial container example

Link: http://tech.yappa.be/symfony-components-in-a-legacy-php-application

Mathias Verraes:
The Repair/Replace Heuristic for Legacy Software
Apr 28, 2016 @ 11:48:06

Mathias Verraes has shared some thoughts about legacy applications and how development should be handled as new features are added and bugs are fixed. He proposes a "heuristic" to keep in mind as you work in your legacy code: the Repair/Replace Heuristic.

Technical Debt is a great metaphor. It shares many analogous properties with financial debt: loans, accrued interest, token payments, bankruptcy… There is a key difference however. We take financial debt with another party. [...] Technical Debt has no measure like money, and no ruleset like Property law, and, more importantly, with Technical Debt there is no other party. The organisation is both the creditor and debtor. [...] In “Managed Technical Debt”, I propose a cheap, imprecise, but surprisingly effective method for mapping and measuring debt. In short, it involves posting stickies whenever progress is impeded by debt, and keep marking the stickies for every incident.

By following this method, you gather together a better overall picture that makes determining the worst debt in your application easier. He proposes using this to follow the Repair/Replace methods: repairing something if it's well architected or replacing it if it's not.

Even when you’re not trying to decide on Repair/Replace — perhaps the decision was already made by others — the process of mapping its history will teach you more about the system and and its design. And one deep insight you learn from temporal modelling.
tagged: legacy code replace repair heuristic software opinion

Link: http://verraes.net/2016/04/repair-replace-heuristic-for-legacy-software/

Intracto Blog:
Paying Technical Debt - How To Rescue Legacy Code through Refactoring
Mar 17, 2016 @ 09:36:16

On the Intracto blog there's a new article posted from Jeroen Moons with some suggestions you can use to pay down technical debt in your legacy code through a bit of effective refactoring.

I have good news for you! Squirrels plant thousands of new trees every year by simply forgetting where they leave their acorns. Also: your project can be saved.

No matter how awful a muddy legacy code mess your boss has bravely volunteered for you to deal with, there is a way out of the mire. There will be twists and turns along the way, and a monster behind every other tree. But, one step at a time, you will get there.

He gives lost of different suggestions for things that can be done to "save your code" and make it not only easier to maintain but more flexible:

  • Persuading the customer
  • Don't replace [a huge mess] with a new one
  • Make problems visible
  • Fight what hurts most
  • Build a library

There's plenty more great suggestions here too with some thoughts and methods to back them up and help you accomplish them in your own code. If you're suffering through a large legacy codebase from day to day, I highly recommend reading through this article.

tagged: technicaldebt legacy legacycode rescue opinion method refactor

Link: http://marketing.intracto.com/paying-technical-debt-how-to-rescue-legacy-code-through-refactoring

Richard Melo:
Run legacy PHP applications from command line
Feb 15, 2016 @ 11:55:49

Richard Melo has a post to his site sharing some helpful advice about running legacy PHP applications from the command line making use of the Symfony Console component to handle some of the heavy CLI duties.

Imagine that you already have a trustfully application that you have been running for a while, but there is a couple of common patterns that make you consider that you need a command line interface (CLI) for your application. [...] So, how do we do this? especially without reinventing the well?

He starts off with an example of the problem, having a bit of a legacy application that needs to take in data (in this case JSON) and handle it would requiring a form submission. He makes use of the Console component to wrap this functionality inside a command and take a JSON file as input. He includes the example code needed to make this simple setup including the Command class itself and a small "bootstrap" command line script to do the actual command execution. The post ends with an example of the command you'd use to run the script and push in the JSON contents.

tagged: commandline symfony console component legacy wrapper introduction tutorial

Link: http://rjsmelo.com/blog/2016/01/19/run-legacy-php-applications-from-command-line/

Ethode.com:
Fixing Spaghetti: How to Work With Legacy Code
Jan 27, 2016 @ 12:09:38

On the Ethode.com blog they've shared some hints for working with legacy code to help you more effectively refactor your way out of the "spaghetti code" you might have right now. These are more general tips and aren't really PHP (or even really web application) specific but they're a good starting place for any refactoring effort.

Legacy code is software that generates value for a business but is difficult for developers to change. [...] The longer this goes on, the more frustrated customers get with the software due to quirky defects, bad user experiences and long lead times for changes. Developers are afraid to make changes due to the "Jenga effect" -- as one piece of code is changed or removed, it often leads to new defects being introduced in the system in sometimes seemingly unrelated places. This compounds into what is known as "technical debt".

They continue on talking about what "spaghetti code" is, how it can happen and some of the warning signs you can use to determine just how far down the rabbit hole you and your code are. They talk about "The Big Rewrite" everyone dreams of but points out that this is almost never a practical path. Instead they offer some good things you can do to help fix the problem: quarantining the problem, refactoring relentlessly, keeping it simple and "doing the dishes" as you go rather than letting the changes pile up.

tagged: legacy code refactor opinion advice fix software development

Link: http://www.ethode.com/blog/fixing-spaghetti-how-to-work-with-legacy-code

Ken Guest:
Scan your code for old-style constructors using PHPUnit
Nov 06, 2015 @ 11:53:26

Ken Guest has a quick post on his site with a helpful hint for those updating older codebases. You can use PHPUnit & PHP_CodeSniffer to locate old constructors in the PHP4 format (constructors named after the classes).

There are less than seven days left until PHP 7 is released, which drops support for old-style constructors – the ones where a method is a constructor if it shares the same name as the class. You don’t want to spend too much time scrolling through codebases for that though do you? Better things to do, like watch videos of conference talks you’ve missed and such. Well, you’re in luck. If you use php_codesniffer (and if you don’t, well shame on you), you’ll be able to get a report of old-style constructors fairly quickly.

He includes examples of the commands you'll need to use to sniff out these older constructors, making use of the built-in "Squiz" coding standard and the "Generic.NamingConventions.ConstructorName" sniff but only on PHP files. He also shows how to alias it to a bash command and export the results to a CSV file.

tagged: scan code legacy constructor php4 php7 phpunit phpcodesniffer

Link: https://kenguest.wordpress.com/2015/11/06/scan-your-code-for-old-style-constructors-using-phpunit/

SitePoint PHP Blog:
Modernizing Legacy Applications in PHP: Review
Jan 15, 2015 @ 12:46:34

The SitePoint PHP blog has posted a review of Paul Jones' "Modernizing Legacy Applications" book. The book share's Paul's gathered knowledge about migrating legacy code into a more modern, maintainable and robust application.

Chances are you’ve come across some horrible legacy code once or twice in your lifetime as a PHP developer. Heck, if you’ve worked with WordPress to any degree, I’m sure you have. I myself have had the satisfying task of modernizing a monolithic ZF1 application, and it was the most mentally exhaustive (but, admittedly, the most educational) year of my career. If only I had had Paul M. Jones’ “Modernizing Legacy Applications In PHP” book back then, I would have been done in half the time, and the work I did would have been twice as good.

Bruno talks briefly about the contents of the book and its goals (from legacy to MVC really). He goes on to point out that the target audience for the book is not the beginner PHP developer but someone that's familiar with good software design concepts and application structure. He goes through the technical side of things, commenting that it's "sound - amazingly so" and how it seems to be taken from a real-life project's refactoring. He wraps things up with a list of some of the pros and cons of the book and a recommendation along with a 4.5 of 5 "elephpant" rating.

tagged: modernize legacy application book review pauljones

Link: http://www.sitepoint.com/modernizing-legacy-applications-php-review/