1 by Mark Scherer CakePHP 3 Hands-on: Developing CakePHP Plugins 

2016 Spryker Systems GmbH 2 Developing CakePHP Plugins About me ● @dereuromark ● Open Source developer since 2007 ● CakePHP developer since 1.2 (2006) ● Core developer since 5+ years. ● www.dereuromark.de 

2016 Spryker Systems GmbH 3 Developing CakePHP Plugins Agenda ● Clean Code: SOLID and Package Principles ● Basics of plugin development ● Examples Details @ www.dereuromark.de/2016/01/29/developing-cakephp-3-plugins-its-fun/ 

2016 Spryker Systems GmbH 4 Developing CakePHP Plugins SOLID ● 5 useful principles 

2016 Spryker Systems GmbH 5 Developing CakePHP Plugins S - Single responsibility ● Keep classes simple, doing a specific task. ● Watch out for constructor argument count. 

2016 Spryker Systems GmbH 6 Developing CakePHP Plugins O - Open/closed principle ● Your code should be open for extension, but closed for modification. ● Code against abstract not concrete classes (interfaces in PHP). 

2016 Spryker Systems GmbH 7 Developing CakePHP Plugins L - Liskov substitution principle ● Every subclass or derived class should be substitutable for their base/parent class. ● Only narrow, never widen, the input for sub classes 

2016 Spryker Systems GmbH 8 Developing CakePHP Plugins I - Interface segregation principle ● Don’t create one interface containing too many different method stubs 

2016 Spryker Systems GmbH 9 Developing CakePHP Plugins D - Dependency inversion principle ● Enforce class dependencies via constructor argument (dependency injection). 

2016 Spryker Systems GmbH 10 Developing CakePHP Plugins Principles of package cohesion ● Reuse-release equivalence principle ● Common-reuse principle ● Common-closure principle Principles of package coupling ● Acyclic dependencies principle ● Stable-dependencies principle ● Stable-abstractions principle 

Developing CakePHP Plugins 2016 Spryker Systems GmbH 11 Reuse-release equivalence principle • Release as much code as can be reused • You can only reuse the amount of code you can actually release 

Developing CakePHP Plugins 2016 Spryker Systems GmbH 12 Building a feature • Plugin vs. core feature 

Developing CakePHP Plugins 2016 Spryker Systems GmbH 13 Building a plugin • Check awesome list first! https://github.com/FriendsOfCake/awesome-cakephp • cake bake plugin • Skeleton builder for composer: https://github.com/usemuffin/skeleton 

Developing CakePHP Plugins 2016 Spryker Systems GmbH 14 Releasing a plugin • Version control • Package definition file • SemVer and BC in minor versions • Meta files and documentation • Tests, CI and coverage And don’t forget to maintain it :-) 

Developing CakePHP Plugins 2016 Spryker Systems GmbH 15 Common-reuse principle • Code that is used together, should be ideally in the same package Common-closure principle • A package should not have more than one reason to change. 

Developing CakePHP Plugins 2016 Spryker Systems GmbH 16 Example https://github.com/dereuromark/cakephp-tools One 2.x plugin to rule them all - or not ;) 

Developing CakePHP Plugins 2016 Spryker Systems GmbH 17 Refactoring • dereuromark/cakephp-shim • dereuromark/cakephp-ajax • dereuromark/cakephp-geo • dereuromark/cakephp-feed • dereuromark/cakephp-tinyauth • dereuromark/cakephp-meta • dereuromark/cakephp-flash • dereuromark/cakephp-mobile On top of dereuromark/cakephp-tools now 6 extracted 3.x plugins with clear groups 

Developing CakePHP Plugins 2016 Spryker Systems GmbH 18 Package coupling (ADP, SDP, SAP) • Prevent cycling dependencies • Change is easiest when a package has not many dependencies (stable), so make sure if it does those are also not blocked for change. • Stable packages ideally have a lot of abstraction (interface, …) exposed to the depending parts so their stability does not prevent them from being extended. 

Developing CakePHP Plugins 2016 Spryker Systems GmbH 19 Examples • https://github.com/UseMuffin/Slug 

www.spryker.com 20 Questions? 

www.spryker.com 21 Happy baking!