rehoard
v0.1.9
Published
ReHoard is a pub/sub state management tool for ReactJs or Nodejs
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Readme
REHOARD
Introduction
Rehoard (simply pub/sub) is a project built in 2015 as an alternative to redux for internal use only (never meant to be used by others, so bug and untested parts might exists).
It is a simply pub/sub for ReactJs, Vanilla JS and NodeJs. It support local/session storage with redo/undo of actions.
Some features
- Web browser, it will save everything by default using sessionStorage in case of accidental web refresh. (check settings, for changing from sessionStorage to localstorage or off)
- Allows redo/undo up to 100 values. You may increase the size and should not affect performance. Note: this is only for state value and not the subcribers. Any subscriber which is not longer subcribed, will not get the changes.
- Nodejs, storage is off by default, also no window object.
- The code tries to be LOOKUP O(1) and broadcast O(N). Note, in order to get O(N) all callbacks get assigned to a setTimout to avoid stack fragmentation so plan accordingly and do not overload with complex operations on each callback.
- Due to queuing up each callback after the broadcast happened, if your code changes the state value too fast, you might have a delayed effect on updates (You should get all messages in order)
Class methods
class ReHoard {
constructor() {
this._reHoardPubSub = new ReHoardPubSub();
}
/* Allow to change default settings.
settings = {
persist : true,
session : true,
timeAlive : 1,
undoRedo: true,
actionsHistory: true,
actionsHistoryLimit: 100,
typeMutable: false,
production: true
};
*/
changeSettings(settings) {
this._reHoardPubSub.changeSettings(settings);
}
// Allows to create the state in a more explict way, a value must be passed to determine its type.
// Dispatch will handle creation, so this is not needed.
create(stateName, stateValue) {
return this._reHoardPubSub._create(stateName, stateValue, "CREATION");
}
// dispatch changes, this will broadcast to any subscribers.
// If state does not exists, it will create it, otherwise, it will update its value.
dispatch(stateName, stateValue, actionReference = "") {
return this._reHoardPubSub.dispatch(stateName, stateValue, actionReference);
}
// subcribes to an existing state, if it does not exists it will throw an exception.
subscribe(stateName, listener, unSubscribeCB) {
return this._reHoardPubSub.subscribe(stateName, listener, unSubscribeCB);
}
// will subscribe if the state exists, otherwise will queue it up once it is created.
subscribeWhenBecomesAlive(stateName, listener, unSubscribeCB) {
return this._reHoardPubSub.subscribeWhenBecomesAlive(stateName, listener, unSubscribeCB);
}
// force a broadcast of the current value to everyone
broadcastState(stateName) {
return this._reHoardPubSub.broadcastState(stateName);
}
// returns current value of the state sync. No broadcasting happens
getCurrentState(stateName) {
return this._reHoardPubSub.getCurrentValue(stateName);
}
// Delete the current state and its listeners.
deleteState(stateName) {
return this._reHoardPubSub.deleteState(stateName);
}
// Redo the value state + action
redo(stateName) {
return this._reHoardPubSub.redo(stateName);
}
// Undo the value to previous one
undo(stateName) {
return this._reHoardPubSub.undo(stateName);
}
// Prints all states
getStatesNames(){
return this._reHoardPubSub.getStatesNames();
}
}
Installation
npm install rehoard --save
or
<script src="dist/js/rehoard.min.js"></script>
Usage
ES6
import Rehoard from 'Rehoard';
const rehoard = new Rehoard();
WWW -- HEAD SCRIPT FIRST
var rehoard = new window.Rehoard();
Code Samples
Example 1
rehoard.create("testOne", 1);
const listener1 = rehoard.subscribe("testOne", function(value) {
console.log(value);
});
rehoard.dispatch("testOne", 100); //console -> 100
rehoard.dispatch("testOne", 1000); //console -> 1000
rehoard.dispatch("testOne", 10000); //console -> 10000
listener1.unSubscribe();
rehoard.dispatch("testOne", 10); // nothing happens
Example 2 -- SUBCRIBE TO A FUTURE STATE
You may subscribe to a state which do not exists at that moment (data coming from other api's). This allows you to setup everything and respond once it exists accordingly
rehoard.subscribeWhenBecomesAlive("testOne", function(value) {
console.log(value);
});
rehoard.create("testOne", 1);
rehoard.dispatch("testOne", 100); //console -> 100
rehoard.dispatch("testOne", 1000); //console -> 1000
rehoard.dispatch("testOne", 10000); //console -> 10000
Example 3 -- DISPATCH
Dispatch will create or update the state implicitly, so Reahord.create() is useful to mark where we create the initial state if needed
rehoard.subscribeWhenBecomesAlive("testOne", function(value) {
console.log(value);
});
rehoard.dispatch("testOne", 100); //console -> 100
rehoard.dispatch("testOne", 1000); //console -> 1000
rehoard.dispatch("testOne", 10000); //console -> 10000
Example 4 -- REDO/UNDO
rehoard.subscribeWhenBecomesAlive("testOne", function(value) {
console.log(value);
});
rehoard.dispatch("testOne", 100); //console -> 100
rehoard.dispatch("testOne", 1000); //console -> 1000
rehoard.dispatch("testOne", 10000); //console -> 10000
rehoard.undo("testOne"); //console --> 1000
rehoard.undo("testOne"); //console --> 100
rehoard.undo("TestOne"); // Nothing
rehoard.redo("TestOne"); // console --> 100
Example 5 -- INMUTABILITY
By default, types cannot be mutaded. If behaviour is needed, you may change them in the settings
rehoard.subscribeWhenBecomesAlive("testOne", function(value) {
console.log(value);
});
rehoard.dispatch("testOne", 100); //console -> 100
rehoard.dispatch("testOne", "hola"); // console --> Error if type inmutability is ON, otherwise "hola"
Example 5 -- ACTION MESSAGES
You may pass Action messages to keep a history of what changed the data
rehoard.subscribeWhenBecomesAlive("testOne", function(value) {
console.log(value);
});
rehoard.dispatch("testOne", 100, "Initial"); //console -> 100
rehoard.dispatch("testOne", 1000, "New value"); //console -> 1000
rehoard.dispatch("testOne", 10000, "Last value"); //console -> 10000
Note 1: I hate the name
Note 2: Not responsible for any damage or bug, it was never intended to be used by other people
Note 3: Tests are busted at the moment, no async check. Will fix them later.