Las maquinas de estado y los flujos de trabajo no son nada nuevo, pero sí quizás algo de lo que has oído hablar pero no te has lanzado a implementar. Cada vez más, esta empezando a formar una parte muy importante de la evolución tecnológica de muchas empresas. Nos pueden servir para solucionar algunos comportamientos en nuestro pequeño proyecto o ser la solución idónea cuando necesitamos aclarar muchos de los procesos de negocio que podemos encontrar en un proyecto muy grande y quizás muy monolítico. Tecnológicamente hablando, es una muy buena herramienta para encapsular una lógica de negocio que suele ser compleja y tediosa. Con esta charla me gustaría compartir mi experiencia trabajando con dichos procesos, ayudaros a entender dichos conceptos y saber diferenciar cuando usar uno u el otro, algo muy importante. Por supuesto, veremos y comentaremos implementaciones en PHP y algunas de las librerías que nos pueden ayudar a agilizar aún más la implementación de estos modelos en nuestros proyectos. URL del evento: http://www.meetup.com/es-ES/PHPMad/events/234585802/

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2. STATE MACHINES AND WORKFLOW
NETS ON YOUR PHP PROJECTS
DANIEL ABAD CAMBRONERO
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3. PRESENTATION
▸ Daniel Abad Cambronero
▸ https://github.com/ruudy-es
▸ @Ruudy_es
▸ Senior Software Developer
WHO I IM
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4. INTRODUCTION
WHY?
▸ What are the three most important ideas in programming?
1. Abstraction
2. Abstraction
3. Abstraction
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5. STATE MACHINES
DEFINITION
▸ Is a computational model used to design both computer
programs and sequential logic circuits
▸ It is conceived as an abstract machine that can be in one of
a finite number of states
▸ No ambiguity is allowed, the machine does not have
human intuition and must follow instructions
▸ It can change from one state to another when triggered by
an event or condition
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6. STATE MACHINES
IMPORTANT CONCEPTS
▸ STATE
▸ TRANSITION
▸ EVENT / TRANSITION CONDITIONS
▸ ENTRY ACTION
▸ EXIT ACTION
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7. STATE MACHINES
THEY ARE AMONG US
This is not brand new, have decades of research behind them,
analyzing and simplifying them.
▸ Electronic design automation
▸ Communication protocol design
▸ Language parsing
▸ To describe neurological systems (biology)
▸ To describe simple parts of the grammars of natural language
(linguistics)
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8. STATE MACHINES
CLOSER THAN YOU THINK
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▸ SM can model a
large number of
problems:

9. STATE MACHINES
ALSO…
▸ It really helps the design process
▸ Just with a look at the drawing, most of the people will
understand what is happening there
▸ It’ll make debugging easier and help us find where the
points of failure are
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10. STATE MACHINES
WOW !
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11. WORKFLOW NETS
DEFINITION
▸ Try to represent a complex human task with an steps
process
▸ Is a subclass of Petri nets intending to model the workflow
of process activities.
Wait…..
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12. WOKFLOW NETS
PETRI NET?
▸ Place / transition net, one of the several mathematical
modelling languages for the description of distributed
systems.
▸ Arcs run from a place to a transition or vice versa, never
between places or between transitions
▸ The model never gets stuck in a transition
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13. WOKFLOW NETS
STRUCTURES
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14. WORKFLOW NETS
GO BACK TO THE DEFINITION
▸ Transitions are assigned to tasks or activities
▸ Places are assigned to the pre/post conditions
▸ Have the addition of a single input (source) place with no
previous transitions, and output place (sink) with no
following transitions.
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15. WORKFLOW NETS
IMPORTANT CONCEPTS
▸ Transitions
▸ Places
▸ Arcs
▸ Marking
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16. WORKFLOW NETS
BENEFITS
▸ Can represent an orchestrated and repeatable pattern of business
activity
▸ It can be depicted as a sequence of operations
▸ Strongly related with how people actually work and how
organizations handle information
▸ A newcomer can easily understand a program just looking at the
Workflow Definition Graph.
▸ Even more easy to debug and notice points of failure than State
Machine
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17. STATE MACHINES VS WORKFLOW NETS
SUMMARISING
STATE MACHINE
‣ Must be only on one state
‣ Has only an exclusive
gateway
‣ Can be cyclic (loop)
‣ Could have transitions
with same name
WORKFLOW NET
‣ Marking could be composed
by multiple places
‣ Has a parallel gateway,
inclusive gateway and
exclusive gateway
‣ Are usually acyclic (start to
finish)
‣ Transitions name must be
unique
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18. ENOUGH THEORY
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19. MAKE THIS USABLE
RECOGNIZING IT
▸ Our model have a state or status field
▸ We are using boolean fields (published, paid)
▸ We are using nullable timestamps (published_at, paid_at)
▸ Having records that are only valid for a given period in
time (subscriptions with start and end date)
▸ Approved / Rejected process depending of multiple
checks
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20. MAKE THIS USABLE
HAVE YOU EVER SEEN THIS?
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▸ You ever thought or see something like this?

21. MAKE THIS USABLE
OR THIS?
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22. MAKE THIS USABLE
HOW TO (PHP)
▸ Encapsulate the graph logic
▸ Design a good architecture around:
▸ Models
▸ Transition conditions
▸ Movements Logic
▸ Events / Automatization
▸ Tests / Documentation
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23. ENCAPSULATE THE GRAPH LOGIC
STATE MACHINES LIBRARIES
▸ https://github.com/winzou/state-machine
▸ https://github.com/winzou/StateMachineBundle
▸ https://github.com/yohang/Finite
▸ https://github.com/Metabor/Statemachine
▸ https://github.com/sebastianbergmann/state
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24. ENCAPSULATE THE GRAPH LOGIC
WORKFLOW NETS LIBRARIES
▸ https://github.com/symfony/workflow (3.x)
▸ https://github.com/fduch/workflow-bundle (2.x
compatibility)
▸ https://github.com/lexik/LexikWorkflowBundle (2.x)
▸ http://www.yiiframework.com/extension/simpleworkflow/
▸ https://github.com/florianv/petrinet
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25. ENCAPSULATE THE GRAPH LOGIC
JUST DO IT
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26. ENCAPSULATE THE GRAPH LOGIC
LOOKS QUITE SIMPLE
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27. EXAMPLE - GRAPHS
STATE MACHINE GRAPH
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28. EXAMPLE - GRAPHS
WORKFLOW NET GRAPH
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29. EXAMPLE - ENCAPSULATE GRAPH LOGIC
LIBRARIES CONFIGURATION
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30. EXAMPLE - DESIGN A GOOD ARCHITECTURE AROUND
MODELS
‣ Not type tables (for SM and WF)
▸ Not enum columns
▸ Easy as VARCHAR or LONGTEXT
▸ Do not try to replicate the SM / WF logic in your model
▸ SM & WF will use attributes for your model
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31. EXAMPLE - DESIGN A GOOD ARCHITECTURE AROUND
SCHEMA
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32. EXAMPLE - DESIGN A GOOD ARCHITECTURE AROUND
TRANSITIONS CONDITIONS
▸ Constraints / Validators
▸ Repositories / Models
▸ Library Events (not recommended)
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33. EXAMPLE - DESIGN A GOOD ARCHITECTURE AROUND
MOVEMENTS LOGIC
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34. EXAMPLE
DEMO TIME

35. DESIGN A GOOD ARCHITECTURE AROUND
EVENTS / AUTOMATIZATION
▸ Crons
▸ Model changes
▸ Transitions
▸ Places / States reach / leave
▸ Logs
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36. DESIGN A GOOD ARCHITECTURE AROUND
TEST & DOCUMENTATION
Is almost impossible to cover all the cases from start.
▸ What happens if an enemy die?
▸ What happens if meanwhile im evading, enemy move to
another zone?
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37. FINAL TIPS
MIX IT!
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▸ A state machine could be part of a transition in a Workflow
net
▸ The final place of a Workflow could be one of the
requirements in a State machine transaction
▸ The enemy state could be another state machine with
different reactions (kind of AI), or a second instance of the
current one, interacting each other.

38. FINAL TIPS
QUITE SIMILAR, WHY TO USE BOTH?
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39. THE END
QUESTIONS
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40. THANKS
THANK YOU!
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Demo repository:
▸ https://github.com/ruudy-es/phpmad-phpmachine-videogame