Post on 14-Jun-2015
description
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I’m Agile, Should I care?
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Agile Cats
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follow XP rules
Agile Cats
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Complexity is Everywhere
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Complexity is Everywhere
and making things simple is hard!
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The Domain Complexity
Customer needs ‘Foo’
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…You think schema ‘Bar’
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Wrong models cause massive accidental complexity
Greg Young10
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Solving the wrong problem
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« It should go faster ! »
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Change the Engine, problem solved!
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Hidden Technical Complexity
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Frameworks?
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How big ?
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Config > Domain
A framework …
= calls you20
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You
Call
the Library
all that matters!
Bad Understanding Poor design No design
Technology locking
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} Generates Complexity !
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Technical debt is watching you!
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Start simplicity now before it blows you!
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How to start ?
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Remember Agile Principles?
the 4 XP Simplicity Rules
• Runs all the tests.• Expresses every idea that we need to express.• Says everything Once And Only Once.• Has no superfluous parts.
28Kent Beck
the 4 elements of Simple design
• Passes its tests• Minimizes duplication• Maximizes clarity• Has fewer elements
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2 final rules
Developing strong skills of detecting duplication, removing duplication,
identifying naming problems, and fixing naming problems equates to learning
everything ever written about object-oriented
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JbRains
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Simple Design Dynamo
(c) jbrains 2013
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What else ?
Better Naming
Iterate & refactor 33
Remove Duplication
What problem are trying to solve?
Always!34
Avoid coupling
everywhere, from classes to libraries
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Be Consistent
Readability, Rules, Conventions36
Be functional!
Be declarative, Immutable, use lambdas
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Practice !
Practice, Practice, Practice ! …
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Get more Fun
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All you need…http://c2.com/cgi/wiki?
ExtremeProgrammingRoadmap
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http://blog.thecodewhisperer.com/2013/12/07/putting-an-age-old-battle-to-rest/
Simple Design Dynamo
Hand written sketches are by me and can be reused under Creative Commons licence, other images are owned by their authors and I really
would like to thank them if I found all credits …41
@rhwy
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Add-on:
lambda refactoring
43The Silence of the Lambas
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interface IPriceCalculator {double GetPrice(string productReference)
}class Basket {
IPriceCalculator calculator;public Basket(IPriceCalculator calculator) {
this.calculator = calculator;}public Result AddProduct(
Product product, int quantity) {Price = calculator.GetPrice(product.Reference);//other magic here
}}
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class UserPriceCalculator : IPriceCalculator{
public double GetPrice(string productReference){ //do some magic stuff here
return price;}
}
var basket = new Basket(new UserPriceCalculator());basket.AddProduct(theProduct, 2);
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class Basket {public Result AddProduct(
Product product, int quantity,Func<string,double> calculator) {
Price = calculator(product.Reference);//other magic
}}
var basket = new Basket();basket.AddProduct(theProduct, 2, x=>x.rawPrice*0,85 );
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Add-on:
More quotes
There is no good
but some of them are useful
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{ Model | Architecture | persistance }
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“Templates, patterns, frameworks don’t solve anything”
they are just tools to start faster