Well yes and no. The Request object is itself not a singleton, BUT... when
you issue the send() method it does a getInstance() of a RequestQueue which
is a singleton. So technically the Request is not a singleton but it is a
single use object
/**
* Schedule this request for transport to server.
*
* The request is added to the singleton class
qx.io.remote.RequestQueue's
* list of pending requests.
*
* @return {void}
*/
send : function() {
qx.io.remote.RequestQueue.getInstance().add(this);
},
Jim
On Thu, Jun 18, 2009 at 1:41 AM, Matthew Gregory <
[email protected] <matthew%[email protected]>> wrote:
> I am quite sure that only being able to use a request object once is a
> limitation of most browsers.
>
> Also Jim I think you have got your terminolgy confused, Request objects
> aren't singletons. A singleton means you can only have one instance of
> that of object at any one time and you usually create them with
> .getInstance() rather than using 'new'.
>
> Jim Hunter wrote:
> > For one, a Request object is a singleton. By definition it can only be
> > used once. I assume they decided to make it a singleton because the life
> > of a Request is not clear cut. At any point in time you are not fully
> > sure if it is done doing it's job so that it can be used again. It was
> > easier to make it a singleton to reduce the amount of housekeeping code
> > needed to manage when it was done and could be used again. And I'm sure
> > the fact that it is asynchronous has a lot to due with it being a
> > singleton.
> >
> > Once you get over the fact that is can only be used once, and code
> > accordingly, you will find it's not that big of a deal.
> >
> > Jim
> >
> >
> >
> > On Wed, Jun 17, 2009 at 2:29 PM, aditya siram <[email protected]
> > <mailto:[email protected]>> wrote:
> >
> > Hi all,
> > It seems as though 'Request' objects can only be used once. Code
> > that tries to reuse [1] will only send the request once. Even though
> > I 'setData' on each button press subsequent sends do nothing.
> > Additionally the "completed" listener also only fires the first time.
> >
> > This is somewhat counter-intuitive and it took me a while to figure
> > out that both the request and listener have to be freshly made [2]
> > with each button press. Is this the intended usage?
> >
> > thanks ...
> > deech
> >
> >
> >
> > [1]
> > var req = new qx.io.remote.Request("/library", "POST");
> >
> > button.addListener("execute", function(e) {
> > req.setData("isbn=" + isbn.getValue());
> > this.debug(req.getData());
> > req.send();
> > });
> >
> > req.addListener("completed", function(e) {
> > resp = qx.util.Json.parseQx(e.getContent());
> > this.debug("done");
> > this.debug(resp);
> > });
> >
> > [2]
> > button.addListener("execute", function(e) {
> > var req = new qx.io.remote.Request("/library", "POST");
> > req.setData("isbn=" + isbn.getValue());
> > this.debug(req.getData());
> > req.send();
> >
> > req.addListener("completed", function(e) {
> > resp = qx.util.Json.parseQx(e.getContent());
> > this.debug("done");
> > this.debug(resp);
> > });
> > });
> >
> >
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> royalty-free distribution of the report engine for externally facing
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