Magento 2.2 example modules to show how things work in M2.2

With di.xml you can do dependency injection, substitute a class, extend a class, change class arguments, create virtual type.

https://github.com/peterlembke/m2-examples/tree/master/src/magento2/app/code/CharZam/DiExample

With Plugins you get access to the variables before they are given to a function, and you get access to the return value before it is sent to the caller.

https://github.com/peterlembke/m2-examples/tree/master/src/magento2/app/code/CharZam/Plugins

You can delay initialization of classes until they are really used. That is done with a proxy. No need to change any code at all, just configure in di.xml that you want this on some class injections. Magento take care of the rest. This can Improove performance!!.

https://github.com/peterlembke/m2-examples/tree/master/src/magento2/app/code/CharZam/UseProxy

With a factory object you can create new empty objects of a specific type. For example when you want to create new customers or products. This example is also about singleton (shared objects).

https://github.com/peterlembke/m2-examples/tree/master/src/magento2/app/code/CharZam/Factory

You can dispatch events and attach any data. In your observer you get READ ONLY data that you can act on. If you need to send data back, then use a plugin instead.

https://github.com/peterlembke/m2-examples/tree/master/src/magento2/app/code/CharZam/Events

With cron you can schedule tasks to run regularily. In this module you see how to set up jobs, deparate business logic and test the job. The documentation is a bit more extensive in this module.

https://github.com/peterlembke/m2-examples/tree/master/src/magento2/app/code/CharZam/Crontab

You can create your own Admin config. See this module how it is done.

https://github.com/peterlembke/m2-examples/tree/master/src/magento2/app/code/CharZam/Config

Resources how you can study Magento 2 more in depth.

There are now five different certifications you can take for Magento 2.2. https://u.magento.com/certification

• MAGENTO 2 CERTIFIED SOLUTION SPECIALIST
• MAGENTO 2 CERTIFIED ASSOCIATE DEVELOPER EXAM
• MAGENTO 2 CERTIFIED PROFESSIONAL FRONT END DEVELOPER
• MAGENTO 2 CERTIFIED PROFESSIONAL JAVASCRIPT DEVELOPER
• MAGENTO 2 CERTIFIED PROFESSIONAL DEVELOPER

Below are resources for the MAGENTO 2 CERTIFIED PROFESSIONAL DEVELOPER exam.

You get practical tips what awaits on the test day.

https://www.integer-net.com/magento-2-certified-professional-developer-about-the-exam/

https://www.mw2consulting.com/blog/tips-prepare-magento-2-developer-certification-exam

Swift Otter give you a large PDF with a lot of information in every area. Very useful.

https://swiftotter.com/technical/certifications/magento-2-certified-developer-study-guide

Exam notes is a very useful condensed material that have a lot of references to other pages.

https://github.com/magento-notes/magento2-exam-notes

The official study guide is not very useful except for the intimidating examples in there.

https://u.magento.com/free-study-guide

You can always trust Alan Storm to have the detailed analyzes of different M2 areas.

https://alanstorm.com/category/magento-2/

The Magento documentation is a valuable source. You will end up here by reference if you follow the "Exam notes" above.

https://devdocs.magento.com/#/individual-contributors

Very useful document that show the intent from Magento, how they expect code to be written.

https://devdocs.magento.com/guides/v2.2/coding-standards/technical-guidelines.html

Magento also has study groups.

https://u.magento.com/magento-2-certified-developer-study-group#.W9rPm3pKgZJ