postal.js/example/standard/js/postal.js

450 lines
No EOL
12 KiB
JavaScript
Executable file

/*
postal
Author: Jim Cowart (http://freshbrewedcode.com/jimcowart)
License: Dual licensed MIT (http://www.opensource.org/licenses/mit-license) & GPL (http://www.opensource.org/licenses/gpl-license)
Version 0.8.9
*/
/*jshint -W098 */
(function ( root, factory ) {
if ( typeof module === "object" && module.exports ) {
// Node, or CommonJS-Like environments
module.exports = function ( _ ) {
_ = _ || require( "underscore" );
return factory( _ );
};
} else if ( typeof define === "function" && define.amd ) {
// AMD. Register as an anonymous module.
define( ["underscore"], function ( _ ) {
return factory( _, root );
} );
} else {
// Browser globals
root.postal = factory( root._, root );
}
}( this, function ( _, global, undefined ) {
var postal;
/*jshint -W098 */
var ConsecutiveDistinctPredicate = function () {
var previous;
return function ( data ) {
var eq = false;
if ( _.isString( data ) ) {
eq = data === previous;
previous = data;
}
else {
eq = _.isEqual( data, previous );
previous = _.clone( data );
}
return !eq;
};
};
/*jshint -W098 */
var DistinctPredicate = function () {
var previous = [];
return function ( data ) {
var isDistinct = !_.any( previous, function ( p ) {
if ( _.isObject( data ) || _.isArray( data ) ) {
return _.isEqual( data, p );
}
return data === p;
} );
if ( isDistinct ) {
previous.push( data );
}
return isDistinct;
};
};
/* global postal, SubscriptionDefinition */
var ChannelDefinition = function ( channelName ) {
this.channel = channelName || postal.configuration.DEFAULT_CHANNEL;
};
ChannelDefinition.prototype.subscribe = function () {
return arguments.length === 1 ?
new SubscriptionDefinition( this.channel, arguments[0].topic, arguments[0].callback ) :
new SubscriptionDefinition( this.channel, arguments[0], arguments[1] );
};
ChannelDefinition.prototype.publish = function () {
var envelope = arguments.length === 1 ?
( Object.prototype.toString.call( arguments[0] ) === "[object String]" ?
{ topic : arguments[0] } :
arguments[0] ) :
{ topic : arguments[0], data : arguments[1] };
envelope.channel = this.channel;
return postal.configuration.bus.publish( envelope );
};
/* global postal */
/*jshint -W117 */
var SubscriptionDefinition = function ( channel, topic, callback ) {
this.channel = channel;
this.topic = topic;
this.callback = callback;
this.constraints = [];
this.context = null;
postal.configuration.bus.publish( {
channel : postal.configuration.SYSTEM_CHANNEL,
topic : "subscription.created",
data : {
event : "subscription.created",
channel : channel,
topic : topic
}
} );
postal.configuration.bus.subscribe( this );
};
SubscriptionDefinition.prototype = {
unsubscribe : function () {
if ( !this.inactive ) {
this.inactive = true;
postal.configuration.bus.unsubscribe( this );
postal.configuration.bus.publish( {
channel : postal.configuration.SYSTEM_CHANNEL,
topic : "subscription.removed",
data : {
event : "subscription.removed",
channel : this.channel,
topic : this.topic
}
} );
}
},
defer : function () {
var self = this;
var fn = this.callback;
this.callback = function ( data, env ) {
setTimeout( function () {
fn.call( self.context, data, env );
}, 0 );
};
return this;
},
disposeAfter : function ( maxCalls ) {
if ( _.isNaN( maxCalls ) || maxCalls <= 0 ) {
throw "The value provided to disposeAfter (maxCalls) must be a number greater than zero.";
}
var self = this;
var fn = this.callback;
var dispose = _.after( maxCalls, _.bind( function () {
this.unsubscribe();
}, this ) );
this.callback = function () {
fn.apply( self.context, arguments );
dispose();
};
return this;
},
distinctUntilChanged : function () {
this.withConstraint( new ConsecutiveDistinctPredicate() );
return this;
},
distinct : function () {
this.withConstraint( new DistinctPredicate() );
return this;
},
once : function () {
this.disposeAfter( 1 );
return this;
},
withConstraint : function ( predicate ) {
if ( !_.isFunction( predicate ) ) {
throw "Predicate constraint must be a function";
}
this.constraints.push( predicate );
return this;
},
withConstraints : function ( predicates ) {
var self = this;
if ( _.isArray( predicates ) ) {
_.each( predicates, function ( predicate ) {
self.withConstraint( predicate );
} );
}
return self;
},
withContext : function ( context ) {
this.context = context;
return this;
},
withDebounce : function ( milliseconds, immediate ) {
if ( _.isNaN( milliseconds ) ) {
throw "Milliseconds must be a number";
}
var fn = this.callback;
this.callback = _.debounce( fn, milliseconds, !!immediate );
return this;
},
withDelay : function ( milliseconds ) {
if ( _.isNaN( milliseconds ) ) {
throw "Milliseconds must be a number";
}
var self = this;
var fn = this.callback;
this.callback = function ( data, env ) {
setTimeout( function () {
fn.call( self.context, data, env );
}, milliseconds );
};
return this;
},
withThrottle : function ( milliseconds ) {
if ( _.isNaN( milliseconds ) ) {
throw "Milliseconds must be a number";
}
var fn = this.callback;
this.callback = _.throttle( fn, milliseconds );
return this;
},
subscribe : function ( callback ) {
this.callback = callback;
return this;
}
};
/*jshint -W098 */
var bindingsResolver = {
cache : {},
regex : {},
compare : function ( binding, topic ) {
var pattern, rgx, prevSegment, result = ( this.cache[ topic ] && this.cache[ topic ][ binding ] );
if ( typeof result !== "undefined" ) {
return result;
}
if ( !( rgx = this.regex[ binding ] )) {
pattern = "^" + _.map( binding.split( "." ),function ( segment ) {
var res = "";
if ( !!prevSegment ) {
res = prevSegment !== "#" ? "\\.\\b" : "\\b";
}
if ( segment === "#" ) {
res += "[\\s\\S]*";
} else if ( segment === "*" ) {
res += "[^.]+";
} else {
res += segment;
}
prevSegment = segment;
return res;
} ).join( "" ) + "$";
rgx = this.regex[ binding ] = new RegExp( pattern );
}
this.cache[ topic ] = this.cache[ topic ] || {};
this.cache[ topic ][ binding ] = result = rgx.test( topic );
return result;
},
reset : function () {
this.cache = {};
this.regex = {};
}
};
/* global postal */
var fireSub = function ( subDef, envelope ) {
if ( !subDef.inactive && postal.configuration.resolver.compare( subDef.topic, envelope.topic ) ) {
if ( _.all( subDef.constraints, function ( constraint ) {
return constraint.call( subDef.context, envelope.data, envelope );
} ) ) {
if ( typeof subDef.callback === "function" ) {
subDef.callback.call( subDef.context, envelope.data, envelope );
}
}
}
};
var pubInProgress = 0;
var unSubQueue = [];
var clearUnSubQueue = function () {
while ( unSubQueue.length ) {
unSubQueue.shift().unsubscribe();
}
};
var localBus = {
addWireTap : function ( callback ) {
var self = this;
self.wireTaps.push( callback );
return function () {
var idx = self.wireTaps.indexOf( callback );
if ( idx !== -1 ) {
self.wireTaps.splice( idx, 1 );
}
};
},
publish : function ( envelope ) {
++pubInProgress;
envelope.timeStamp = new Date();
_.each( this.wireTaps, function ( tap ) {
tap( envelope.data, envelope );
} );
if ( this.subscriptions[envelope.channel] ) {
_.each( this.subscriptions[envelope.channel], function ( subscribers ) {
var idx = 0, len = subscribers.length, subDef;
while ( idx < len ) {
if ( subDef = subscribers[idx++] ) {
fireSub( subDef, envelope );
}
}
} );
}
if ( --pubInProgress === 0 ) {
clearUnSubQueue();
}
return envelope;
},
reset : function () {
if ( this.subscriptions ) {
_.each( this.subscriptions, function ( channel ) {
_.each( channel, function ( topic ) {
while ( topic.length ) {
topic.pop().unsubscribe();
}
} );
} );
this.subscriptions = {};
}
},
subscribe : function ( subDef ) {
var channel = this.subscriptions[subDef.channel], subs;
if ( !channel ) {
channel = this.subscriptions[subDef.channel] = {};
}
subs = this.subscriptions[subDef.channel][subDef.topic];
if ( !subs ) {
subs = this.subscriptions[subDef.channel][subDef.topic] = [];
}
subs.push( subDef );
return subDef;
},
subscriptions : {},
wireTaps : [],
unsubscribe : function ( config ) {
if ( pubInProgress ) {
unSubQueue.push( config );
return;
}
if ( this.subscriptions[config.channel][config.topic] ) {
var len = this.subscriptions[config.channel][config.topic].length,
idx = 0;
while ( idx < len ) {
if ( this.subscriptions[config.channel][config.topic][idx] === config ) {
this.subscriptions[config.channel][config.topic].splice( idx, 1 );
break;
}
idx += 1;
}
}
}
};
/* global localBus, bindingsResolver, ChannelDefinition, SubscriptionDefinition, postal */
/*jshint -W020 */
postal = {
configuration : {
bus : localBus,
resolver : bindingsResolver,
DEFAULT_CHANNEL : "/",
SYSTEM_CHANNEL : "postal"
},
ChannelDefinition : ChannelDefinition,
SubscriptionDefinition : SubscriptionDefinition,
channel : function ( channelName ) {
return new ChannelDefinition( channelName );
},
subscribe : function ( options ) {
return new SubscriptionDefinition( options.channel || postal.configuration.DEFAULT_CHANNEL, options.topic, options.callback );
},
publish : function ( envelope ) {
envelope.channel = envelope.channel || postal.configuration.DEFAULT_CHANNEL;
return postal.configuration.bus.publish( envelope );
},
addWireTap : function ( callback ) {
return this.configuration.bus.addWireTap( callback );
},
linkChannels : function ( sources, destinations ) {
var result = [];
sources = !_.isArray( sources ) ? [ sources ] : sources;
destinations = !_.isArray( destinations ) ? [destinations] : destinations;
_.each( sources, function ( source ) {
var sourceTopic = source.topic || "#";
_.each( destinations, function ( destination ) {
var destChannel = destination.channel || postal.configuration.DEFAULT_CHANNEL;
result.push(
postal.subscribe( {
channel : source.channel || postal.configuration.DEFAULT_CHANNEL,
topic : sourceTopic,
callback : function ( data, env ) {
var newEnv = _.clone( env );
newEnv.topic = _.isFunction( destination.topic ) ? destination.topic( env.topic ) : destination.topic || env.topic;
newEnv.channel = destChannel;
newEnv.data = data;
postal.publish( newEnv );
}
} )
);
} );
} );
return result;
},
utils : {
getSubscribersFor : function () {
var channel = arguments[ 0 ],
tpc = arguments[ 1 ];
if ( arguments.length === 1 ) {
channel = arguments[ 0 ].channel || postal.configuration.DEFAULT_CHANNEL;
tpc = arguments[ 0 ].topic;
}
if ( postal.configuration.bus.subscriptions[ channel ] &&
Object.prototype.hasOwnProperty.call( postal.configuration.bus.subscriptions[ channel ], tpc ) ) {
return postal.configuration.bus.subscriptions[ channel ][ tpc ];
}
return [];
},
reset : function () {
postal.configuration.bus.reset();
postal.configuration.resolver.reset();
}
}
};
localBus.subscriptions[postal.configuration.SYSTEM_CHANNEL] = {};
/*jshint -W106 */
if ( global && global.hasOwnProperty( "__postalReady__" ) && _.isArray( global.__postalReady__ ) ) {
while(global.__postalReady__.length) {
global.__postalReady__.shift().onReady(postal);
}
}
/*jshint +W106 */
return postal;
} ));