Here is a working example: http://jsfiddle.net/zkuMv/
On 13 Aug., 11:43, Moo <[email protected]> wrote: > Hi T.J., > > thank you for your reply. You are right about the idle-flag, I already > renamed it :) > I followed your advice and moved up the "idle = false" thing, but it > does not work so well. > With a slow connection the code below works fine: > > var MessageQueue = Class.create({ > initialize: function(url) { > this.url = url; > this.queue = []; > this.busy = false; > }, > add: function(message) { > if (this.busy) this.queue.push(message) > else this.push(message); > }, > push: function(message) { > this.busy = true; > new Ajax.Request(this.url, { > onSuccess: function() { > alert(message); > this.busy = false; > if (this.queue.size() > 0) { > this.push("queued: " + this.queue.shift()); > } > }.bind(this) > }); > } > > }); > > var mq = new MessageQueue("/ajax_html_echo/"); > mq.add("First"); > mq.add("Second"); > mq.add("Third"); > > But when the backend is fast and you type the hell out of your > keyboard, it seems, that the part > this.push("queued: " + this.queue.shift()); > is never reached. There is no output with "queued:" > > My thought was, that when new messages arrive, while a request is in > progess, to store them until the request is finished. Then all > messages in the stack should be sent until the busy-flag is set to > false. Therefore I had it below the if-condition. > > I saw that the guys at jQuery use a sentinel "inprogress" which they > unshift/shift to/from the array. But I don't know if that would be > helpful here. > > It would be super great if you have the time, to have a second look at > it! > > Thank you so much > > On 13 Aug., 10:18, "T.J. Crowder" <[email protected]> wrote: > > > > > Hi, > > > Your "idle" flag -- which you seem to use to mean "busy processing a > > request", which I found *really* confusing at first :-) -- is getting > > cleared inappropriately whenever you pull something from your queue. I > > don't know that that's the problem, but it's probably wrong. The error > > is in your onComplete function: > > > if (this.queue.size() > 0) { > > console.log("queue-size > 0, so enqueue next item"); > > this.push("queued: " + this.queue.shift());} > > > this.idle = false; // <=== Error if `if` above was true > > > If there's something in the queue, you call `push`, which sets the > > flag, starts a new async request, and returns. But then you clear the > > flag, so the next time `add` gets called, it'll think it should call > > `push` rather than `queue.push` even though there's an outstanding > > request. > > > If you just move the `this.idle = false;` line above the `if` > > statement, it should sort out this issue. Whether it solves the > > problems you described I can't say, but I suspect it'll solve at least > > some of them. > > > HTH, > > -- > > T.J. Crowder > > Independent Software Consultant > > tj / crowder software / comwww.crowdersoftware.com > > > On Aug 12, 7:55 pm, Moo <[email protected]> wrote: > > > > Hi there, > > > > I want to ensure, that messages are posted in the order, they come in > > > the stack. My tests at jsFiddle were okay, but with a quick backend > > > (where the requests are processed very fast) the order is crap. > > > Sometimes items are posted twice. Is there anybody who can help me > > > out? Thank you all! > > > > var MessageQueue = Class.create({ > > > initialize: function(url) { > > > this.url = url; > > > this.queue = []; > > > this.idle = false; > > > }, > > > add: function(message) { > > > if (this.idle) { > > > console.log("idle, so saved to queue: " + message); > > > this.queue.push(message); > > > } else { > > > console.log("not idle, so pushed directly: " + message); > > > this.push(message); > > > } > > > }, > > > push: function(message) { > > > this.idle = true; > > > console.log("Ajax.Request will be called now!"); > > > new Ajax.Request(this.url + "&message=" + > > > encodeURIComponent(message), { > > > onComplete: function() { > > > console.log("successfully sent: " + message); > > > if (this.queue.size() > 0) { > > > console.log("queue-size > 0, so enqueue next > > > item"); > > > this.push("queued: " + this.queue.shift()); > > > } > > > this.idle = false; > > > }.bind(this) > > > }); > > > } > > > > });- Zitierten Text ausblenden - > > > - Zitierten Text anzeigen -- Zitierten Text ausblenden - > > - Zitierten Text anzeigen - -- You received this message because you are subscribed to the Google Groups "Prototype & script.aculo.us" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/prototype-scriptaculous?hl=en.
