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BECOMINGCERTIFIED

Becoming Certified - (c) @VinaiKopp - #MageTitansMCR - 2018-11-10

Who here has sat inone or more Magento 1 exams?


Who here has sat inone or more Magento 2 exams?


SO LET'S NOT TAKETHIS TOO SERIOUSLY


Magento 1 Certificaton

!=Magento 2 Certification


How so?


Magento 1 &Magento 2:

Questions are developed by aCommunity Advisory Board


Magento 1 &Magento 2:

Each question is written to fit anExam Blueprint Objective


Magento 1 != Magento 2:

Time frame andReview Process


Magento 1:

Months of online meetings and reviews

Magento 2:

One week focus group, all in one room


Magento 1:

Rather contrived, memorization friendly

Magento 2:

Scenario based, real life, more natural


Magento 1:

Questions about Config XML Paths and Class Names.


The Reasoning was:

"Magento Developers with experience will have written them countless times and know them by heart."


This was before Magicento existed...


Magicento:▸ Code generation▸ Autocompletion


Magento 2:

No questions about thingswith IDE autocompletion


How do the questions look like?


Each item has 3 Parts:▸ The Scenario▸ The Stem▸ The Options


▸ The Scenario

Information required to choose the correct answer


▸ The Stem

The question


▸ The Options

The possible answers


Valid answer keys:▸ Choose 1 out of 4▸ Choose 2 out of 4▸ Choose 3 out of 5


If more than one answer has to be selected,the number of required options is stated like this:

"Which three actions do you take? (Choose three)"


For questions with multiple answers,the right number of options have to be selected and

all selected answers have to be correct.


▸ No trick questions▸ No “none of the above”▸ No “all of the above”

▸ No “which of the following are true”▸ No double negatives


ACTIONABLE QUESTIONS!


"How do you fix the issue?"

"What actions do you take?"

"What is the effect of that code?"


EXAMPLEQUESTION


(1/2)

You are working for an extensions vendor who protects their intellectual property by validating licenses against a license server.

Customers are complaining that running any bin/magento command isvery slow after installing one of the companies extensions.

The extension adds a command to bin/magento.

While investigating, you discover the following code in the command class:

public function __construct($license){ $this->isLicenseValid = $this->validateLicense($license); parent::__construct();}


(2/2)

public function __construct($license){ $this->isLicenseValid = $this->validateLicense($license); parent::__construct();}

How do you resolve the issue?

A. Implement local license validation instead of over the internet

B. Move the validateLicense() call into the execute() method

C. Check the license at random samples instead of every time

D. Cache the validation result in the Magento config cache


Answer:B. Move the validateLicense() call into the execute() method


Magento Technical Guidelines

2.3. Class constructor can have only dependency assignment operations and/or argument validation

operations. No other operations are allowed.


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

Example Excerpt:


But why?


Why?Becoming Certified - (c) @VinaiKopp - #MageTitansMCR - 2018-11-10

(back to the topic of exam questions)


SOME QUESTIONS HAVE QUALIFIERS.

What are qualifiers?


Qualifiers are part of the Stem:

▸ Keeping simplicity in mind ...▸ Keeping maintainability in mind ...▸ Keeping compatibility in mind ...▸ Keeping testability in mind ...


WHAT IS THE PURPOSE OF QUALIFIERS?

They guide us to the correct answer.


Magento is flexible.

There are many ways to accomplish a goal.


We often have to make decisionshow to implement a requirement.


For questions with qualifiersoften more than one answer is technically correct.


Do we use ...

a preference, a type argument configuration

or a plugin?


Do we use ...

an ORM model or a Api Data model?


Do we inject ...

an interface or a concrete implementation?


Depending on the circumstances,every approach could be valid.


Faster development vs. better maintainability

More upgradable code vs. more performant code

...


▸ lifetime of the project▸ project budget▸ developer skill level

▸ security considerations (internal / external access)▸ use of third party modules▸ desired code reuse


Qualifiers tell us which answer to choosefor the given scenario.


Maintainability?

Probably rules out options where code is copied.Favor answers that make changes and upgrades simpler.


Compatibility?

Rule out options with a higherextension conflict probability.


Simplicity?

Favor expressive options using theleast number of elements.


Testability or Reusability?

Favor answers that allow replacing collaboratorswith test doubles or other classes.


EXAMPLEQUESTION


You need to customize the Magento_Checkout/js/proceed-to-checkoutJavaScript module.

How do you do that, keeping compatibility in mind?

A. Add a path override configuration to the requirejs-config.js

B. Add a global map alias override to the requirejs-config.js

C. Copy the file proceed-to-checkout.js to the folder Magento_Checkout/js/ of the active frontend theme

D. Add a JavaScript mixin to the requirejs-config.js


Answer:D. Add a JavaScript mixin to the requirejs-config.js


GETTING READY


Study Guide

The study guide is based on the exam blueprint.


SWIFT OTTER STUDY GUIDES

Based on the Magento U study guidebut much expanded.

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

The Official Technical Developer Guidelines

(ask Why?)


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

Don't memorize OOP patterns and principles for the exam.

Without experience, that does more harm than good.


Better to go from first principles:▸ What is a source code dependency?

▸ What are the consequences of a dependency?


Deeper understandingof the principles behind the labels.


▸ Interfaces and the Liskov Substitution principle▸ Coupling and Cohesion

▸ Favor Composition over Inheritance


Familiarize yourself withKent Beck’s 4 rules of simple design.


1. Passes all tests

2. Expresses intent 3. No duplication

4. Fewest possible elements


When a question has the qualifier

“Keeping simplicity in mind...”

apply these rules.


SMART GUESSING


And finally...


becoming certifieds23276.pcdn.co/wp-content/uploads/2018/11/vinai-kopp... · 2018-11-19 · who...

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