@ospin/fct-graph

This documentation is likely to remain sparse, as it is for internal use and under development!

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Table of Contents

• Use Overview
  • Instantiation
  • Action
  • Inspection
  • From/To JSON
  • Public Methods that Mutate
• Class Structure and Hierarchies
• Factories
• Seeders
• Contributing
• Upcoming

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Use Overview

The FCTGraph functions like a traditional graph with several features on top. Most importantly, all functionalities (nodes) have many slots, which hold data about themselves. Slots connect to other slots (if they are compatible) via dataStreams (edges).

The following is a selected showcase of the public functions on the various base objects of:

• FCTGraph (graph)
• Functionality (node)
• Slot (connection rule object)
• DataStream (edge)

Instantiation!

const { FCTGraph, functionalities, slots } = require('@ospin/FCTGraph') // or import

// first, let's set up some seed data. Functionalities (nodes) have many dataStreams (edges)...
const tempOutSlotData = { name: 'temp out', type: 'OutSlot', ... } /* see OutSlot.SCHEMA */
const tempSensorData = { slots: [ tempOutSlotData ], ... } /* see TemperatureSensor.SCHEMA */

const tempInSlotData = { name: 'temp in', type: 'InSlot', ... } /* see InSlot.SCHEMA */
const pidControllerData = { slots: [ tempInSlotData ], ... }  /* see PIDController.SCHEMA */

// ...and instantiate our FCTGraph
const fctGraph = new FCTGraph({
  functionalities: [ tempSensorData, pidControllerData ],
  ...,
}) /* see FCTGraph.SCHEMA */)

// we can also add functionalities after the fact
fctGraph.addFunctionality({ ...heaterActuatorData })

fctGraph.functionalities
// -> a temperature sensor with a temperature outslot
// -> a PID controller with a temperature in slot
// -> a heater actuator

Action!

// ...continuing from above. let's connect the temperature sensor to the PIDController
const [ tempSensor, pidController, heaterActuator ] = fctGraph.functionalities

const { slots: [ tempOutSlot, ... ] } = tempSensor
const { slots: pidControllerSlots } = pidController

// get those slots on the PIDController which are connectable to the temperature sensor
const [ connectableSlot, ... ] = tempOutSlot.filterConnectableSlots(pidControllerSlots)

// connect!
const { dataStream } = tempOutSlot.addConnectionTo(connectableSlot)
// -> dataStream { id, sourceSlotName: 'temp out', sinkSlotName: 'temp in', ... }

Inspection!

// ...continuing from above
tempSensor.isPossibleToConnectToFct(pidController)
// -> true

fctGraph.getConnectableFctsToTargetFct(pidController)
// -> [ tempSensor, ... ]


// Graph mutating public methods return a standard response object:
// response object: { error: <bool>, errorMsg: <string>, ...relevantData }

const goodFctData = /* valid data for a new functionality */
const { error, errorMsg, functionality } = fctGraph.addFunctionality(fctData)

console.log(error) // -> false
console.log(errorMsg) // -> null
console.log(functionality instanceof Functionality) // -> null

From JSON, all life flows, and returns

fctGraph.serialize()
// -> returns the nested data object (no instances)

const fctGraphJSON = JSON.stringify(fctGraph)
// -> returns valid JSON with no information lost

const fctGraphClone = FCTGraph.new(JSON.parse(fctGraphJSON))
// -> works!

Public Methods that Mutate

Where appropriate (and hopefully whenever this package is extended) public methods which mutate instances in a major way (e.g. adding functionalities to the graph, connecting slots, etc.) return a response object. Response objects are intended to be useful in cases where a caller attempts to mutate the FCTGraph (or a portion of it) in a way that would ultimately fail data validation. The response objects will return actionable information for the caller.

const failure = fctGraph.addFunctionality({ name: 123, ...validData })
// {
//   error: true,
//   errorMsg: 'Failed to add fct: <fct data>. Underlying error: name must be a string',
//   functionality: <{ ...the failed functionalities data }>,
// }

const success = fctGraph.addFunctionality({ name: 'Dr. Strangelove\'s Bunker Heater', ...validData })
// {
//   error: false,
//   errorMsg: null,
//   functionality: <the added functionality>,
// }

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Class Structure and Hierarchies

FCTGraph

// an FCTGraph has many Functionalities
Functionality (virtual)
├── Actuator (virtual)
│   └── HeaterActuator
├── Controller (virtual)
│   └── PIDController
├── InputNode (virtual)
│   └── PushIn
├── OutputNode (virtual)
│   ├── PushOut
│   └── IntervalOut
└── Sensor (virtual)
    └── TemperatureSensor

// a Functionality has many Slots
Slot (virtual)
├── InSlot
└── OutSlot

// a Slot has many DataStreams
DataStream

All non-virtual classes (e.g. HeaterActuator, InSlot, etc.) compose the JOIous module, which provides the following:

• post .constructor - asserts the instance's data against the JOI SCHEMA (which provides nested data validation) as a final step
• .serialize (virtual) - blows up - informing the user that the class that composed JOIous needs a .serialize method
• .sortAndSerialize - uses .serialize returns the (deeply) sorted object
• .toJSON - uses .sortAndSerialize
• .toString - inspects deeply for richer print outs
• [util.inspect.custom] - inspects deeply for richer print outs in Node

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Factories

Functionalities and Slots need somewhat intelligent instantiation as they are meant to be serialized to and from JSON. For this reason, Factories exist for instantiating both Functionalities and Slots. Instantiating an FCTGraph from parsed JSON will automatically delegate to the factories as it builds the hierarchy.

• FCTGraph delegates to the FunctionalityFactory when functionalities are added. The factory will attempt to find the appropriate functionality sub-class via the type and subType key values and blow up if it can not find one.

• Functionality delegates to the SlotFactory when slots are added. The factory will attempt to find the appropriate slot sub-class via the type key value and blow up if it can not find one.

Functionalities and Slots can also be created directly calling the constructors on their non-virtual classes. See Class Structure and Hierarchies

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Seeders

NOTE: Seeders are meant for testing purposes ONLY. While they carry a high test coverage %, they (likely) don't have the 100% Green™ coverage that the rest does.

The package comes with seeders which have the same class hierarchy as the primary models:

FCTGraphSeeder

FunctionalitySeeder (virtual)
├── ActuatorSeeder (virtual)
│   └── HeaterActuatorSeeder
├── ControllerSeeder (virtual)
│   └── PIDControllerSeeder
├── InputNodeSeeder (virtual)
│   └── PushInSeeder
├── OutputNodeSeeder (virtual)
│   ├── PushOutSeeder
│   └── IntervalOutSeeder
└── SensorSeeder (virtual)
    └── TemperatureSensorSeeder

SlotSeeder (virtual)
├── InSlotSeeder
└── OutSlotSeeder

All virtual seeders (e.g. HeaterActuatorSeeder, InSlotSeeder etc.) compose the FactorySeeder module, which provides the following static methods (which extend to their children):

• static get SEED_METHOD (virtual) - blows up - informing the user that the class that composed FactorySeeder needs a static .SEED_METHOD getter. This method should used to call a constructor/factory's creation method
• static generate (virtual) - blows up - informing the user that the class that composed FactorySeeder needs a static .generate method. This method should be used to create fake data which matches the class SCHEMA
• .seedOne - expects a data object. delegates to generate and SEED_METHOD
• .seedMany - expects an array of data objects
• .seedN - expects an object and a count

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Contributing

This repo employs the github action semantic-release, which, on approved PRs to main, sniffs the PR title/commit message to automatically bump the semantic versioning and publish the package to NPM.

All PRs to the main branch should indicate the semantic version change via the following rules.

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Upcoming:

• reject setting properties on the core classes that should not change throughout the lifetime of an object (type, subType, name, etc.)
• disconnect connections between slots
• dataStreams reference slots instead of just the slot name (works with instantiating from slot name) and still serialize to contain the slot names