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![$sum = function ($carry, $item) { return $carry + $item; }
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foreach ([1, 2, 3] as $value) {
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SIMPLE
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![$acc = 0;
foreach ([1, 2, 3] as $value) {
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SIMPLE
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Simple vs EasySimple vs Easy](https://image.slidesharecdn.com/phpbarcelona-150218101924-conversion-gate01/75/PHP-Barcelona-Monthly-Talk-Feb-2015-31-2048.jpg)
![UserPostController Command Bus
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(Economy Account)](https://image.slidesharecdn.com/phpbarcelona-150218101924-conversion-gate01/75/PHP-Barcelona-Monthly-Talk-Feb-2015-70-2048.jpg)
![UserPostController Command Bus
UserRegistratorCommandHandler
UserRegistrator
Domain
Event
Publisher
UserRegisteredDomainEv
entSubscriber
UserAccountOpener
User UserRepository Event
Subscribers
.
.
.
POST /users
[
userId: 0db90987-5ce1-4683-bb05-7d1b5539cb0b
]
Command
Handlers
.
.
.
UserRegisteredDomainEvent
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BASIC REQUEST
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UserRegistrationCommand
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analyticsContextId
id
(Economy Account)
UserModule
EconomyModule](https://image.slidesharecdn.com/phpbarcelona-150218101924-conversion-gate01/75/PHP-Barcelona-Monthly-Talk-Feb-2015-71-2048.jpg)
Uploaded bySergi González Pérez
PHP Barcelona Monthly Talk Feb 2015
The document discusses tackling complex code through various techniques including: 1. Dividing complex code into smaller pieces, testing each piece individually, and then recombining (divide, test, and conquer approach). 2. Using domain-driven design concepts like bounded contexts, domain modules, domain events, and repositories to separate code by domain. 3. Applying concepts like CQRS and hexagonal architecture to further separate code into independent layers. 4. Learning from past mistakes in a real project like prematurely coupling components and letting the database schema dictate the domain model.
![Detrás del Backend [phpDay 2015]](https://cdn.slidesharecdn.com/ss_thumbnails/detrasdelbackendnocmnts-150202122910-conversion-gate02-thumbnail.jpg?width=640&height=640&fit=bounds)
PHP Barcelona Monthly Talk Feb 2015
- 1.
- 2. DDD as animplementation detail Eloi Poch Sergi González
- 3. Who$are$we?$ $ ! es.linkedin.com/in/eloipoch/$ $ $ @eloipoch$ $ Eloi.poch@akamon.com$ Eloi!Poch! ! Technical!Lead!at!@Akamon! • So8ware$Developer$ • Clojure$developer$wannabe$ • Want$to$code$in$Castefa$beach$while$drinking$wine$
- 4. (conj '(1 23) 4)
- 5. Who$are$we?$ $ ! es.linkedin.com/in/sergigp/$ $ $ “SergiGP$ $ Sergi.gonzalez@akamon.com$ Sergi! ! Technical!Lead!at!@Akamon! • So<ware$Developer$ • Chief$Trolling$Officer$ • Two$animals$remaining$to$have$an$urban$zoo$
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- 8. A little biton Akamon before we deal with the technical stuff
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- 14. Flash Client GameServer Backend AS3 Nova Java JReactive & Vertx PHP Horus
- 16. @eloipoch @jordillonch @SergiGP @jorgeavila_ss@jdiezc @jvalduvieco @amassa5 Who we are? The backend team
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- 19. Performance Big Data Difficult Algorithms Concurrency Realtime analytics Scalability
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- 22. Code Complexity Big ballof mud Shared State Coupling
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- 26. Tackling Complex Code ThePhilosophy
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- 29. Simple vs Easy $mysqli= new mysqli("localhost", "horus", "olakease", “suite"); $mysqli->query("INSERT INTO users …”)) SIMPLE EASY /** * @ORMEntity * @ORMTable(name="product") */ class Product
- 30. $sum = function($carry, $item) { return $carry + $item; } array_reduce([1, 2, 3], $sum); $acc = 0; foreach ([1, 2, 3] as $value) { $acc += $value; } SIMPLE EASY Simple vs EasySimple vs Easy
- 31. $acc = 0; foreach([1, 2, 3] as $value) { $acc += $value; } SIMPLE EASY (reduce + [1 2 3]) Simple vs EasySimple vs Easy
- 32. Simplicity vs Easiness •Easy to understand • Easy to debug • Easy to change, flexibility, maintenable • Easy to use • Hard to debug • Hard to change
- 33. Complected • Something doesmore than one thing and you can’t split it easily • Source of accidental complexity • DON’T DO IT
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- 35. Do not complect,compose
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- 42. Self Empowerment Never askfor permission unless it would be reckless not to
- 43. Trust Great teams areunafraid to air their dirty laundry, admit their mistakes, their weaknesses and their concerns without fear. Patrick Lencioni
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- 47. YAGNI You Aren’t GonnaNeed It
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- 49. • DDD Tactical: •Application Services • Domain Services • Domain Events • Repositories • AR & VO • DDD Strategical: • Modules • Bounded Contexts • SubDomains • Context Maps
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- 56. Tackling Complex Code ThePractice
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- 67. Big Picture • Directories:773 • Files: 1501 • Lines of code: 113885 • Non-Comment Lines of Code: 88806 (80%) • Average Class Length: 14 lines • Average Method Length: 2 lines • Cyclomatic Complexity / LLOC: 0.06 • Cyclomatic Complexity / Number of Methods: 1.21 HORUS
- 68. Big Picture ofour Code in Horus • Directories: 773 / 558 • Files: 1501 / 1001 • Lines of code: 113885 / 41205 • Non-Comment Lines of Code: 88806 (80%) / 38045 (92%) • Average Class Length: 14 lines / 5 lines • Average Method Length: 2 lines / 2 lines • Cyclomatic Complexity / LLOC: 0.06 / 0.03 • Cyclomatic Complexity / Number of Methods: 1.21 / 1.14
- 70. UserPostController Command Bus UserRegistratorCommandHandler UserRegistrator Domain Event Publisher UserRegisteredDomainEv entSubscriber UserAccountOpener UserUserRepository Event Subscribers . . . POST /users [ userId: 0db90987-5ce1-4683-bb05-7d1b5539cb0b ] Command Handlers . . . UserRegisteredDomainEvent User HORUS BASIC REQUEST UserRegistrationCommand UserRegistrationCommand userId analyticsContextId userId analyticsContextId UserRegisteredDomainEvent userId analyticsContextId id (Economy Account)
- 71. UserPostController Command Bus UserRegistratorCommandHandler UserRegistrator Domain Event Publisher UserRegisteredDomainEv entSubscriber UserAccountOpener UserUserRepository Event Subscribers . . . POST /users [ userId: 0db90987-5ce1-4683-bb05-7d1b5539cb0b ] Command Handlers . . . UserRegisteredDomainEvent User HORUS BASIC REQUEST UserRegistrationCommand UserRegistrationCommand userId analyticsContextId userId analyticsContextId UserRegisteredDomainEvent userId analyticsContextId id (Economy Account) UserModule EconomyModule
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- 74. Tackling Complex Code TheConclusions
- 75. Mistakes • Do notstore domain events • Own libraries for CQRS & DDD • Do not use Domain Services • Domain events with wrong identifiers • Couple App Services to Commands & Queries • Not start earlier some Modules/Bounded Contexts
- 76. Mistakes • Let theDB guide us • Let the framework guide us
- 77. Problems • Domain Events:Lost of order (async) • Doctrine • Unit Of Work + Integration Test = Fail • Embedded: Identifier or not • Behat: The Container
- 78. Tips & Tricks •Repositories: • Just add, save and find • Use of DQL implies the schema is too complex • Controllers: 50 lines of code • Application Services: Avoid business logic • One step at time: Hex. Arch. -> DDD -> CQRS -> ES? • Start it as a Module and promote it later to BC
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