ProppyJS - Functional composition of props for components
npm install proppy
> Functional props composition for components
- Guide
- Installation
- Usage
- Single functions
- Composition
- Providers
- Subscription
- API
- withProps
- withState
- compose
- withReducer
- withHandlers
- withStateHandlers
- withObservable
- withTimer
- onChange
- map
- shouldUpdate
- didSubscribe
- willDestroy
- emit
- handleReceivedProps
- create
---
With npm:
``
$ npm install --save proppy
Via unpkg CDN:
`html
`
Let's first import a function of our choice:
`js`
import { withState } from 'proppy';
Now we can create our factory:
`js`
const P = withState('counter', 'setCounter', 0);
The factory function can now be called to get the instance:
`js`
const p = P();
Accessing props:
`js
console.log(p.props);
// { counter: 0, setCounter: Function }
p.props.setCounter(5);
console.log(p.props.counter);
// 5
`
Destroying the instance:
`js`
p.destroy();
You can also compose multiple factories together using the compose function:
`js
import { compose, withProps, withState } from 'proppy';
const P = compose(
withProps({ foo: 'foo value' }),
withState('counter', 'setCounter', 0),
withState('age', 'setAge', 20),
);
`
You can now get your instance by calling the returned function:
`js
const p = P();
console.log(p.props);
// {
// foo: 'foo value',
//
// counter: 0,
// setCounter: Function,
//
// age: 20,
// setAge: Function
// }
`
Providers are values which are made accessible to instances.
When we call our factory function to get the instance, we can optionally pass an object that will contain all our providers:
`js
import { compose, withProps } from 'proppy';
const P = compose(
// value already known
withprops({
foo: 'foo value',
}),
// value will be obtained from providers
withProps((props, providers) => ({
// props is { foo: 'foo value' } here`
bar: providers.bar,
}),
);
Now we can pass the providers object when calling P:
`js
const p = P({
bar: 'bar value',
});
console.log(p.props);
// {
// foo: 'foo value',
// bar: 'bar value',
// }
`
Subscribing to props changes:
`js`
const unsubscribe = p.subscribe(props => console.log(props));
To Unsubscribe:
`js`
unsubscribe();
> withProps(props)
> withProps((currentProps, providers) => props)
Used for generating initial props.
Examples:
Directly passing the props object:
`js`
const P = withProps({ foo: 'foo value' });
Returning the props from a function:
`js`
const P = withProps((currentProps, providers) => {
return {
foo: 'foo value'
};
});
> withState(stateName, setterName, initialState)
Used for state management.
Examples:
`js`
const P = withState('counter', 'setCounter', 0);
> compose(...factories)
Used for composing multiple factories into a single one.
Examples:
`js`
const P = compose(
withProps({ foo: 'foo value '}),
withprops({ bar: 'bar value' }),
withState('counter', 'setCounter', 0),
);
> withReducer(stateName, dispatcherNAme, reducer, initialState)
For generating props via reducer functions.
Arguments:
1. stateName (String): Name of the prop where state will be setdispatcherName
1. (String): Name of the prop for setting dispatch functionreducer
1. (Function): Accepting (state, action), and returning new stateinitialState
1. (Any): Initial state to begin with
Example:
`js
function reducer(state, action) {
switch (action.type) {
case 'INCREMENT':
return { value: state.value + 1 };
case 'DECREMENT':
return { value: state.value - 1 };
default:
return state;
}
}
const P = withReducer('counter', 'dispatch', reducer, { value: 0 });
const p = P();
p.dispatch({ type: 'INCREMENT' });
console.log(p.props.counter) // { value: 1 }
`
You can also pass functions to dispatch:
`js`
p.dispatch(function (props, providers) {
return { type: 'INCREMENT' };
});
> withHandlers(handlers)
Used for handling side-effects.
Examples:
Basic handler:
`js`
const P = withHandlers({
handleFoo: (props, providers) => () => console.log('handling foo!')
});
A better example with composition:
`js
const P = compose(
withState('counter', 'setCounter', 0),
withHandlers({
incrementBy: (props, providers) => (n) => {
props.setCounter(props.counter + n);
},
}),
);
const p = P();
p.incrementBy(1);
console.log(p.props.counter); // 1
`
> withStateHandlers(initialState, handlers)
Used for state management via handlers.
Examples:
`js
const P = withStateHandlers(
// initial state
{
counter: 0,
},
// handlers
{
incrementBy: (props, providers) => (n) => {
// return new state
return {
counter: props.counter + n,
};
}
}
);
const p = P();
p.incrementBy(5);
p.incrementBy(5);
console.log(p.props.counter); // 10
`
> withObservable((props, providers) => props$)
Used for returning an Observable of props.
Examples:
`js
import { of } from 'rxjs';
const P = withObservable((props, providers) => {
return of({
foo: 'foo value',
});
});
`
For advanced usage, look into proppy-rx package, where you can also access incoming props as an Observable.
> withTimer(timer, props)
> withTimer(timer, (props, providers) => props)
Sets props after timer has elapsed.
Examples:
`jsfoo
// prop is set after 1 second`
const P = withTimer(1000, { foo: 'foo value' });
Accessing current props and providers:
`js`
const P = withTimer(100, (props, providers) => ({
foo: 'foo value',
}));
> onChange(propName, (prop, providers) => props)
> onChange(
> (prevProps, nextProps) => true,
> (props, providers) => props
> )
> onChange(
> propName,
> (props, providers, cb) => void
> )
Detect a change in props, and return new props.
Examples:
Change foo, when counter changes:
`jschanged foo with counter ${props.counter}
const P = compose(
withProps({ foo: 'initial foo value' })
withState('counter', 'setCounter', 0),
onChange('counter', (props, providers) => ({
foo:
}))
);
const p = P();
console.log(p.props.foo); // initial foo value
p.props.setCounter(10);
console.log(p.props.foo); // changed foo with counter 10
Detecting complex changes:
`js
const P = compose(
withState('counter', 'setCounter', 0),
onChange(
// detect
(prevProps, nextProps) => true,
// return props
(props, providers) => props
)
);
`
Returning async props:
`js
const P = compose(
withState('counter', 'setCounter', 0),
onChange(
// detect
(prevProps, nextProps) => true,
// return props by callback
(props, providers, cb) => {
cb(props);
}
)
);
`
> map((props, providers) => props)
Used for mapping incoming props to returned props.
Examples:
`js`
const P = compose(
withProps({ foo: 'foo value' }),
map(props => ({ foo: props.foo.toUpperCase() })),
);
> shouldUpdate((prevProps, nextProps, providers) => true)
Used for limiting the events
Examples:
`js`
const P = compose(
withState('counter', 'setCounter', 0),
shouldUpdate((prevProps, nextProps) => {
// emit further only if counter is an even number
return nextProps.counter % 2 === 0;
});
);
> didSubscribe((props, providers) => {})
For handling side-effects upon first subscription.
Examples:
`js
const P = didSubscribe((props, providers) => {
// do something
// optionally return a function
// that will be called when instance is destroyed
return () => {};
})
`
> willDestroy((props, providers) => {})
For handling side-effects when instance is destroyed.
> emit((cb, props, providers) => {})
For emitting new props after subscription.
Examples:
`js
const P = emit((cb, props, providers) => {
cb({ foo: 'foo value' });
// optionally return a function
// that will be called when instance is destroyed
return () => {};
});
`
> handleReceivedProps(true|false)
> handleReceivedProps((receivedProps) => {})
Accept props coming from parent instances.
> create(options)
Convenience function for creating your own functions, that can return factories.
All the other functions in this library are built by using this create function internally.
Arguments:
* options.initialize (Function)options.didSubscribe
* (Function)options.willDestroy
* (Function)options.handleReceivedProps
* (Boolean|Function)
Examples:
A producer of props:
`js
function withFoo() {
return create({
initialize() {
// has access to:
// - this.props
// - this.providers
this.set({
foo: 'foo value',
});
}
});
}
`
A mapper of props:
`js``
function capitalizeFoo() {
return create({
handleReceivedProps(receivedProps) {
this.set({
...receivedProps,
foo: typeof receivedProps.foo !== 'undefined'
? receivedProps.foo.toUpperCase()
: undefined,
})
}
});
}