Entities Entities The Theory The Theory

Who am I Working for over 3 years on Node.js Authored >40 NPM packages Contributed to even more CTO Insight Replay Founder netscan.co @thanpolas

The MVC bankruptcy The MVC bankruptcy @thanpolas

Models represent a schema Models are FAT Business logic leaks to Controllers Handling of higher level operations MVC is not enough today The MVC bankruptcy The MVC bankruptcy @thanpolas

Active Record (Single Table) Validations Relations Methods (db related) It's an ORM configuration The MVC bankruptcy The MVC bankruptcy Models represent a schema Models represent a schema @thanpolas

You gotta see it to believe it Ok, I bet you've seen it! It's ugly It's not entirely the Model's fault Decouple The Model bankruptcy The Model bankruptcy Models are FAT (core models > 4k lines) Models are FAT (core models > 4k lines) @thanpolas

Send verification email Perform multiple table OPs Talk to services ​memcache pupsub redis The MVC bankruptcy The MVC bankruptcy Business logic leaks to Controllers Business logic leaks to Controllers @thanpolas

The MVC bankruptcy The MVC bankruptcy Business logic leaks to Controllers Business logic leaks to Controllers How do you run the operation from a Cron Job? Back office? API? CLI? How do you test? @thanpolas

Multiple tables involved Multiple Services involved Complex Auth Schemes Real Time The MVC bankruptcy The MVC bankruptcy Handling of higher level operations Handling of higher level operations @thanpolas

Way more complex flows Service oriented design SaaS / PaaS Infrastructure Multiple inputs The MVC bankruptcy The MVC bankruptcy MVC is not enough today MVC is not enough today @thanpolas

Ok, now what? Ok, now what? @thanpolas

Decouple Decouple Separate Separate Draw Lines Draw Lines @thanpolas

Meet Meet MVCe MVCe @thanpolas

@thanpolas

Think of Entities as... Think of Entities as... Pipes Data transformers Operation plexers Switches Adaptors Aggregators Entities are inspired by the Service Layer design pattern @thanpolas

Core Principles Core Principles Human readable API Normalised Input Normalised Output @thanpolas

Core Principles Core Principles Human readable API Human readable API userEnt.create(udo); userEnt.delete(uid); userEnt.sendMessage(fromId, toId, message); videoEnt.process(videoPath); Methods that make sense Think action not operation @thanpolas

Core Principles Core Principles Normalised Input Normalised Input userEnt.create({ firstName: "Thanasis", lastName: "Polychronakis", email: "thanpolas@gmail.com", }); Well documented expectations No need to be validated @thanpolas

Core Principles Core Principles Normalized Output Normalized Output console.log(udoOut); { "id": "3kdp349r7fhw", "firstName": "Thanasis", "lastName": "Polychronakis", "email": "thanpolas@gmail.com", } Aggregates datasets Normalizes db idiomacies Consistency @thanpolas

CRUD API CRUD API @thanpolas

The CRUD Primitives The CRUD Primitives create() read() readOne() readLimit() update() delete() count() @thanpolas

it depends™ it depends™ Validations Validations @thanpolas

Validations Validations Is there an ORM CRUD OP? Perform actions before or after ORM? Do you trust your input? Outside world? Internal invocation? Better not to trust anybody @thanpolas

NO NO Are entities only for Are entities only for the backend? the backend? @thanpolas

REMEMBER REMEMBER Entities are Entities are Normalizers Aggregators Pipes Your business logic @thanpolas