Controls several instances of Request and its variants to run only one request at a time.
Request.Queue = new Class({
Implements: [Options, Events],
Binds: ['attach', 'request', 'complete', 'cancel', 'success', 'failure', 'exception'],
options: {/*
onRequest: function(argsPassedToOnRequest){},
onSuccess: function(argsPassedToOnSuccess){},
onComplete: function(argsPassedToOnComplete){},
onCancel: function(argsPassedToOnCancel){},
onException: function(argsPassedToOnException){},
onFailure: function(argsPassedToOnFailure){},
onEnd: function(){},
*/
stopOnFailure: true,
autoAdvance: true,
concurrent: 1,
requests: {}
},
initialize: function(options){
if (options){
var requests = options.requests;
delete options.requests;
}
this.setOptions(options);
this.requests = {};
this.queue = [];
this.reqBinders = {};
if (requests) this.addRequests(requests);
},
addRequest: function(name, request){
this.requests[name] = request;
this.attach(name, request);
return this;
},
addRequests: function(obj){
Object.each(obj, function(req, name){
this.addRequest(name, req);
}, this);
return this;
},
getName: function(req){
return Object.keyOf(this.requests, req);
},
attach: function(name, req){
if (req._groupSend) return this;
['request', 'complete', 'cancel', 'success', 'failure', 'exception'].each(function(evt){
if (!this.reqBinders[name]) this.reqBinders[name] = {};
this.reqBinders[name][evt] = function(){
this['on' + evt.capitalize()].apply(this, [name, req].append(arguments));
}.bind(this);
req.addEvent(evt, this.reqBinders[name][evt]);
}, this);
req._groupSend = req.send;
req.send = function(options){
this.send(name, options);
return req;
}.bind(this);
return this;
},
removeRequest: function(req){
var name = typeOf(req) == 'object' ? this.getName(req) : req;
if (!name && typeOf(name) != 'string') return this;
req = this.requests[name];
if (!req) return this;
['request', 'complete', 'cancel', 'success', 'failure', 'exception'].each(function(evt){
req.removeEvent(evt, this.reqBinders[name][evt]);
}, this);
req.send = req._groupSend;
delete req._groupSend;
return this;
},
getRunning: function(){
return Object.filter(this.requests, function(r){
return r.running;
});
},
isRunning: function(){
return !!(Object.keys(this.getRunning()).length);
},
send: function(name, options){
var q = function(){
this.requests[name]._groupSend(options);
this.queue.erase(q);
}.bind(this);
q.name = name;
if (Object.keys(this.getRunning()).length >= this.options.concurrent || (this.error && this.options.stopOnFailure)) this.queue.push(q);
else q();
return this;
},
hasNext: function(name){
return (!name) ? !!this.queue.length : !!this.queue.filter(function(q){ return q.name == name; }).length;
},
resume: function(){
this.error = false;
(this.options.concurrent - Object.keys(this.getRunning()).length).times(this.runNext, this);
return this;
},
runNext: function(name){
if (!this.queue.length) return this;
if (!name){
this.queue[0]();
} else {
var found;
this.queue.each(function(q){
if (!found && q.name == name){
found = true;
q();
}
});
}
return this;
},
runAll: function(){
this.queue.each(function(q){
q();
});
return this;
},
clear: function(name){
if (!name){
this.queue.empty();
} else {
this.queue = this.queue.map(function(q){
if (q.name != name) return q;
else return false;
}).filter(function(q){
return q;
});
}
return this;
},
cancel: function(name){
this.requests[name].cancel();
return this;
},
onRequest: function(){
this.fireEvent('request', arguments);
},
onComplete: function(){
this.fireEvent('complete', arguments);
if (!this.queue.length) this.fireEvent('end');
},
onCancel: function(){
if (this.options.autoAdvance && !this.error) this.runNext();
this.fireEvent('cancel', arguments);
},
onSuccess: function(){
if (this.options.autoAdvance && !this.error) this.runNext();
this.fireEvent('success', arguments);
},
onFailure: function(){
this.error = true;
if (!this.options.stopOnFailure && this.options.autoAdvance) this.runNext();
this.fireEvent('failure', arguments);
},
onException: function(){
this.error = true;
if (!this.options.stopOnFailure && this.options.autoAdvance) this.runNext();
this.fireEvent('exception', arguments);
}
});