datahub

A tiny data layer for any frontend project.

Datahub suggests you to only manipulate data to make your application logic clearer and more easy to read. All you need to do is to listen&invoke data change by config each component. And each component should totally unaware others' existance.

Install

npm install datahubjs

Or you can use the file in dist, a global variable named DataHub is provided.

Data Flow

 _______                               ______________               ------------ 
|       |  hub.set("any-prop", val)   |              |   _digest() |            |
| state |  -------------------------> |   trasient   | ----------->|   updated  |
|       |                             |     state    |             |    state   |
|_______|                             |______________|             |____________|
                                          ^      |                       | 
                                          |      |                       |   invoke callbacks
                                          |_ _ _ |                       V
                                    hub.set('any-prop', val)    |------------------|
                                                                | update component |   
                                                                |------------------| 

API

####set(propName, value)

Update a specified propName as the passed-in value.

Notice: the prop will update after a digest cycle, not update immediately.

####get(propName, value)

Get a specifed propName value;

###on(props, callback)

Listen to any number of prop changes. The callback will invoke after a digest cycle only if any listened props were changed and arguments will be map to the listened props.

If props is not provided, the callback will register as a global callback. It means the callback will be invoked after each digest.

var hub = datahub.getInstance();
hub.on('hello', function(val) {
  console.log('hello is: ' + val);
});
hub.on(['hello', 'world'], function(hello, world) {
  console.log('composite: '+ hello + " , " world);
});
hub.set('hello', 1);
hub.set('world', 2)

=>

hello is: 1
composite: 1 , 2

###watch(expression, callback)

Listen to an expression and campare the newVal with the old value every digest cycle. It will invoke the callback once detect the newVal is different with the oldVal.

var hub = datahub.getInstance();
hub.watch('hello + world', function(val) {
  console.log(val);
});
hub.set('hello', 10);
hub.set('world', 3);

=>

output: 13

License

MIT