buster-core

Version:

0.4.0 (2011-08-26)

Module:

require("buster-core");

In browsers:

buster;

A collection of utilities commonly used across Buster.JS projects. The module is stable and can be freely used when extending Buster, or for any other projects should you wish to do so.

Methods

buster.bind()

buster.bind(object, methodOrString);

Binds a function to an object, such that its this value is fixed regardless of how it’s called. The function works much like `Function.prototype.bind <https://developer.mozilla.org/en/JavaScript/Reference/Global_Objects/Function/bind>`_. It is provided here to work in environments that do not support Function.prototype.bind.

var homer = {
    name: "Homer",

    burp: function () {
        return this.name + " goes buuuuuurp";
    }
};

var func = buster.bind(homer, homer.burp);
func(); // "Homer goes buuuuuurp"

var func2 = buster.bind(homer, "burp");
func2(); // "Homer goes buuuuuurp"

buster.create()

buster.create(object);

Cross-browser implementation of Object.create.

buster.create only supports creating a new object with the specified object as its prototype. It does not support property descriptors.

buster.extend()

buster.extend(target[, source1[, source2[, ...]]]);

Extends the target object by copying all the properties of all the sources onto it. Sources as processed in order. The method also returns the target object.

var target = { id: 42, num: 0 };

target = buster.extend(target,
                       { id: 13, name: "One" },
                       { name: "Two", prop: "erty" });

//=> { id: 13, num: 0, name: "Two", prop: "erty" }

buster.nextTick()

buster.nextTick(callback);

Calls the callback on the next tick of the event loop. On Node.js this method simply delegates to process.nextTick. In the browser, nextTick is emulated by passing the callback to setTimeout(callback, 0).

buster.functionName()

buster.functionName(func);

Returns the name of the function, or an empty string if the function is a falsy value. The method tries three approaches, returning an empty string if all approaches fail:

1. Return func.displayName
2. Return func.name
3. Attempt to infer the name through func.toString()

Event emitter

A standalone Node.js and browser compatible event emitter API.

eventEmitter.create()

var emitter = buster.eventEmitter.create();

Creates a new event emitter object.

eventEmitter.addListener()

emitter.addListener(event, listener[, thisObject])

Adds the listener function to the named event. The optional thisObject will be the this of the listener when called.

emitter.addListener("myevent", function () {
    // ...
});

eventEmitter.on()

emitter.on(event, listener[, thisObject]);

Alias to addListener.

eventEmitter.once()

emitter.once(event, listener[, thisObject]);

Like addListener, but is removed after one emission.

emitter.once("myevent", function () {
    console.log("hello");
});
emitter.emit("myevent"); // Logs "hello"
emitter.emit("myevent"); // Nothing happens

eventEmitter.emit()

emitter.emit(event[, arg1, arg2, ...]);

Emits the event, triggering all the listeners with the given arguments.

emitter.addListener("myevent", function (a, b, c) {
    console.log(a, b, c);
});
emitter.emit("myevent");            // undefined, undefined, undefined
emitter.emit("myevent", {}, "foo"); // {}, "foo", undefined

eventEmitter.removeListener()

emitter.removeListener(event, listener);

Removes the listener for that event.

var mylistener = function () {};
emitter.addListener("myevent", mylistener);
emitter.removeListener("myevent", mylistener);
emitter.emit("myevent"); // Does not call 'mylistener'

eventEmitter.hasListener()

emitter.hasListener(event, listener[, thisObject]);

Tests if the event emitter has the given listener for that event, optionally a listener for the given thisObject.

var func1 = function () {};
var func2 = function () {};
var thisObj = {};

emitter.addListener("foo", func1);
emitter.addListener("bar", func2,  thisObj);

emitter.hasListener("foo", func1); // true
emitter.hasListener("foo", func2); // false

emitter.hasListener("bar", func1); // false
emitter.hasListener("bar", func2); // true

emitter.hasListener("bar", func2, {});      // false
emitter.hasListener("bar", func2, thisObj); // true