Yes, HTTPService requests can be operated in async mode but what happens if the state of your database requires serialization of requests or what happens if you need to debug your server-side code and you are doing this through the use of some kind of log file - async server requests can make debugging a problem even if you have some kind of debugging system that lets you step through your server side code. I think if you think about this you might come to the same conclusion I did.
Also I found that my async HTTPService requests were failing sometimes for odd reasons until I chose to run them serially one after another through a single HTTPService Object. Since I have a lot of experience coding AJAX based systems it was very easy for me to adapt to the apparent problems I was seeing and rather than bank on the code working when it appeared to be failing I chose to run my requests one after another to facilitate debugging and maintain my database state. Keep in mind when requests are being run async it may be possible for a subsequent request to be run out of order, in case it matters what order the requests need to be run in. Maybe your async HTTPService Requests may not run into the same problems mine did or maybe yours are simpler than mine are but this is what I did to ensure mine would work. ----- Original Message ---- From: dorkie dork from dorktown <[EMAIL PROTECTED]> To: [email protected] Sent: Sunday, April 8, 2007 7:25:08 AM Subject: Re: [flexcoders] Sending multiple HTTPService requests - how to really cancel all but the last arent httpservice requests asyncronous? i thought you could have a bunch running at the same time and receive a response from each as you got them. are they returning in linear order? in an application i'm working on i make three different service request calls. i'll see if i can find out how to cancel them. On 07 Apr 2007 23:48:50 -0700, Ray Horn <[EMAIL PROTECTED] net> wrote: I too ran into this sort of problem however I chose to build a REST Serialization mechanism that guarantees I can queue-up requests as deep as I need and then execute them serially since that is the way my REST backend needs the requests in order to maintain database state. ----- Original Message ---- From: coderdude2 <[EMAIL PROTECTED] com > To: [email protected] Sent: Saturday, April 7, 2007 5:05:02 PM Subject: [flexcoders] Sending multiple HTTPService requests - how to really cancel all but the last I'm using several HTTPService calls to plain old REST API's on the backend. If the end user clicks some of the UI controls multiple times quickly, many calls to these services get queued up, and it can take a long time for all the data to be retrieved. For ex. clicking on a list box item sends requests to refresh all the data, and if the user were to use the keyboard to quickly scroll through the listbox, many many calls would get queued up. I've tried setting the concurrency= "last" on the httpservices, but it appears the only effect of that is to make the UI change only when the last dataset is received, but still all the service calls continue to be queued and there is a long delay after making many calls. I've also tried <httpservice> .disconnect( ) and .cancel() before making any new backend call but it didn't appear to have any effect as far as preventing many calls from getting queued up. Thanks in advance for any ideas. I know I could also look into retrieving all the data only once and doing local Flex filtering on it rather than getting the data fresh from the backend each time, but for now it's just easier to make the backend calls and use the DB to do the proper filtering and querying.
