loud-accessors

LoudAccessors - JavaScript event emitting attribute accessors

LoudAccessors is a super tiny JavaScript constructor (CoffeeScript class) implementing event emitting getter and setter. It is intended to be used as a micromodule or as a base class to build upon.

It mixes in the eventspitter event micromodule and provides two additional instance methods:

• get( attr_name ) gets the value of an attribute and emits the read:attr_name event (where attr_name is the name of the attribute that was read)
• set( attr_name, attr_value ) sets the value of an attribute, and triggers the change:attr_name event

Additionally, it provides a class method:

• attrAccessor( attr_name, [attr2_name], [...] ) on environment supporting Object.defineProperty it defines getter and setter for the attribute(s), so that accessing it directly triggers the events.

Example (CoffeeScript)

class Person extends LoudAccessors
  constructor: ( name ) ->
    @set "name", name
 
john = new Person "John"
 
john.get "name"                      # => returns "John" and triggers "read:name" 
john.set "name", "Johnny"            # => sets name to "Johnny" and triggers "change:name" 
john.set "name", "Joe", silent: true # => sets name to "Joe" without triggering events 
 
# Or, where Object.defineProperty is supported: 
 
class Person extends LoudAccessors
  @attrAccessor "name"
 
john.name            # => returns "John" and triggers "read:name" 
john.name = "Johnny" # => sets name to "Johnny" and triggers "change:name"