hypeReduce 3.0

hypeReduce is a simple yet powerful State-Management Library for JS / TS - Browser & Node

The Concept

In hypeReduce everything is managed by dispatching actions, which are just pure data objects that look like

{
  type: 'MY_ACTION',
  payload: 'Do cool stuff'
}

Actions are responsible for updating application state using pure functions.

Install

npm i hypereduce

hypeReduce is broken into 2 main apis; state and route.

The state.api manages state

The route api manages url routes and interacts with the state.api

// API's

import { d, dispatch, manageState } from 'hypereduce/fns/state.api'     // For state management
import { goto, manageRoutes } from 'hypereduce/fns/route.api'           // For route-handling

...

An intro to State Management

Let's say our application state looks like...

{
  counter: 1
}

In order for hypeReduce to manage it, we wrap it in the manageState function...

manageState({
  counter: 1
})

hypeReduce lets you turn static state into dynamic state by swapping out values for dynamic-nodes. We'll swap the value of 1 for a dynamic-node...

manageState({
  counter: d()
})

And give it an initial value of 1...

manageState({
  counter: d({
    init: 1
  })
})

And tell it which actions to respond to in order to produce new state

// The following increment function takes in state and action and returns
// either state + action.payload, or if action.payload isn't provided... state + 1
const INC = (state, action) => state + (action.payload || 1)

// We can register the INC function on a dynamic-node.
// Now the node is 'listening' for actions of type 'INC'.
manageState({
  counter: d({
    init: 1,
    actions: {
      INC
    }
  })
})

To get the state of the counter out into our app somewhere, we first annotate it with connects...

const INC = (state, action) => state + (action.payload || 1)

manageState({
  counter: d({
    connects: ['counter'],
    init: 1,
    actions: {
      INC
    }
  })
})

And then register corresponding connects to it from within the app...

const INC = (state, action) => state + (action.payload || 1)

manageState({
  counter: d({
    connects: ['counter'],
    init: 1,
    actions: {
      INC
    }
  })
})

connect('counter', _ => console.log(`Got a new value ${_}`))

Now we can dispatch actions and trigger the connection to fire with the updated value...

const INC = (state, action) => state + (action.payload || 1)

manageState({
  counter: d({
    connects: ['counter'],
    init: 1,
    actions: {
      INC
    }
  })
})

connect('counter', _ => display(`Got a new value ${_}`)) // Got a new value 1
dispatch({ type: 'INC' }) // Got a new value 2
dispatch({ type: 'INC', payload: 2 }) // Got a new value 4

At the moment though, if we had two nodes listening for INC then both nodes would increment. To make actions more targeted, use the node's name as an id that can be targeted...

const INC =
  (id) =>
    (state, action) =>
      id === action.payload.id
        ? state + (action.payload.by || 1)
        : state

manageState({
  counter: d({
    connects: ['counter'],
    init: 1,
    actions: {
      INC: INC('counter')
    }
  })
})

connect('counter', _ => display(`Got a new value ${_}`)) // Got a new value 1
dispatch({ type: 'INC', payload: { id: 'counter' } }) // Got a new value 2
dispatch({ type: 'INC', payload: { id: 'counter', by: 2 } }) // Got a new value 4

$ Wildcards

If you want a node to respond to ALL actions that it recieves - use the $ wildcard.

const INC = state => state + 1

manageState({
  counter: d({
    connections: ['counter'],
    init: 1,
    $: INC('counter')
  })
})

connect('counter', _ => display(`Got a new value ${_}`))
dispatch({ type: 'ANY_ACTION' }) // Got a new value 2
dispatch({ type: 'AND_ANOTHER' }) // Got a new value 3

_ Passdowns

Let's say you have a dynamic-node that is an object. And let's say you want to be able to respond to actions at the full object level, but also at lower-down nodes...

No problem - use the _ passdown.

manageState({
  field1: d({
    connects: ['field1'],
    init: { text: 'hello', enabled: true },
    actions: {
      DISABLE_FIELD1,
      ENABLE_FIELD1
    },
    _: {
      text: d({
        actions: {
          SET_TEXT_FIELD_ONE
        }
      }),
      enabled: d({}) // we can just set this to an empty object to pass back the current state
    }
  })
})

And Remember ... State is composable

const field1 = d({
  connects: ['field1'],
  init: { text: 'hello', enabled: true },
  actions: {
    DISABLE_FIELD1,
    ENABLE_FIELD1
  },
  _: {
    text: d({
      actions: {
        SET_TEXT_FIELD_ONE
      }
    }),
    enabled: d({})
  }
})

const field2 = ...

manageState({
  view1: {
    field1,
    field2
  }
})

Type-Safety with Typescript

Here we are explicitly stating that field 1 is an object with keys text and enabled. text is either a string or a dynamic-state-node of type string. enabled is either a boolean or a dynamic-state-node of type boolean.

We can also specify the type that we expect the connection to get within the app.

  manageState({
    field1: d<{text: (string | DStateNode<string>), enabled: (boolean | DStateNode<boolean>) }>({
      connects: ['field1'],
      init: { text: 'hello', enabled: true },
      actions: {
        DISABLE_FIELD1,
        ENABLE_FIELD1
      },
      _: {
        text: d<string>({
          actions: {
            SET_TEXT_FIELD_ONE
          }
        }),
        enabled: d({}) // we can just set this to an empty object to pass back the current state,
      }
    })
  })

  connect<{text: string, enabled: boolean }>('field1', _ => display(`GOT VALUE OF ${pretty(_)}`))
  dispatch({ type: 'SET_FIELD1', payload: 'YO!' })
  dispatch({ type: 'DISABLE_FIELD1' })

Connecting to React

In a state directory...

import { d, manageState, getConnections, connect, disconnect } from 'hypereduce/lib/fns/state.api'
import { useState, useEffect } from 'react'

const INC =
  (id: string) =>
    (state: number, action: { type: string, payload: { id: string, by: number }}) =>
      id === action.payload.id
        ? state + (action.payload.by || 10)
        : state

// useConnect for REACT + HypeReduce

export const useConnect = (connectKey: string) => {
  const [state, setState] = useState(getConnections(connectKey))
  useEffect(() =>
    connect(connectKey, newValue => {
      setState(newValue)
      return disconnect(connectKey)
    })
  )
  return state
}

// HypeReduce State

export const hypeReduce = () => manageState({
  count: d<number>({
    init: 3,
    connects: [ 'count' ],
    actions: {
      INC: INC('count')
    }
  })
})

Consider wrapping dispatches into simple messages...

import { dispatch } from "hypereduce/lib/fns/state.api";

export const INC_COUNT = () => dispatch({ type: 'INC', payload: { id: 'count' } })

Then in your components...

import { hypeReduce, useConnect } from '../state'
import { INC_COUNT } from '../state/messages'

hypeReduce()

export default function Home() {
  const count = useConnect('count') // This syncs to the HypeReduce 'connect' labelled 'count'
  return <div id="app">
    <h1>Counter</h1>
    <h1>{count}</h1>
    <button onClick={INC_COUNT}>
      Click me
    </button>
  </div>
}