relegater v1.0.2
relegater
provide functions in order to delegate a property access or method call for base object to other.
Interfaces of the functions imitate delegate
method in Ruby on Rails.
example
import { delegate, $delegate } from 'relegater';
const baseObj = {
a: 1, b: 'b'
};
const delegated = {
c: () => 'c',
d: {
e: true
}
};
// delegate() create new object.
// no update to base object exist.
var result = delegate(baseObj).to(delegated, 'c', 'd').self;
result.a // 1
result.b // 'b'
result.c() // 'c'
result.d.e // true
baseObj.a // 1
baseObj.b // 'b'
baseObj.c // undefined
baseObj.d // undefined
// $delegate() modify base object destructively.
$delegate(baseObj).to(delegated, 'c', 'd');
baseObj.a // 1
baseObj.b // 'b'
baseObj.c() // 'c'
baseObj.d.e // true
baseObj is a object which receive actually property accesses or method calls.
when you want to delegate reference for baseObj to other, you should pass baseObj to delegate()
or $delegate()
.
delegate()
delegate()
create a new object which extends baseObj.
this function don't modify baseObj, so you use the created object instead of baseObj.
you can get the object from delegate({}).self
.
$delegate()
$delegate()
modify baseObj directly and destructively, but not modify prototype of baseObj.
how to delegate
delegate()/$delegate()
return object which has following property.
to(delegated, prop1, prop2, ... propX)
this method return a new object which has same interface. this method can chain. when a property is specified twice in the method chain, later is preferred.
delegated is a object which baseObj delegate some property accesses or method calls to.
- delegated must be object. if this is not object, runtime error raise.
prop1~X is variable arguments. each prop is string which presents property name in delegated;
if propX does not exist in delegated, it is ignored.
self this property exist only when you use
delegate()
.this object base on baseObj and has all properties which are specified by
to()
.
License
MIT License