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Twittercan-define
Exports the define method that defines observable properties and their behavior on a prototype object.
define(prototype, propDefinitions)
Define observable properties, type conversion, and getter/setter logic on prototype objects.
var define = require("can-define");
var Greeting = function(message){
this.message = message;
};
define(Greeting.prototype,{
message: {type: "string"}
});
Parameters
- prototype
{Object}:The prototype object of a constructor function or class. The prototype object will have getter/setters defined on it that carry out the defined behavior. The prototype will also contain all of can-event's methods.
- propDefinitions
{Object<String,PropDefinition>}:An object of properties and their definitions.
Use
can-define provides a way to create custom types with observable properties.
Where can-define/map/map and can-define/list/list provide more functionality, they also make
more assumptions on the type constructor. can-define can be used
to create completely customized types.
The following creates a
Person constructor function:
var define = require("can-define");
var Person = function(first, last){
this.first = first;
this.last = last;
};
define(Person.prototype,{
first: { type: "string" },
last: { type: "string" },
fullName: {
get: function(){
return this.first+" "+this.last;
}
}
});
This can be used to create Person instances with observable properties:
var person = new Person("Justin", "Meyer");
person.first //-> "Justin"
person.last //-> "Meyer"
person.fullName //-> "Justin Meyer"
person.on("fullName", function(ev, newVal, oldVal){
newVal //-> "Ramiya Meyer"
oldVal //-> "Justin Meyer"
});
person.first = "Ramiya"
The observable properties call Observation.add so they can be observed by can-compute.