It is most definitely not an "oversight"! Folks have been fussing about it since the beta, but it was a conscious decision, based, I'm sure on potential network failure scenarios. None of the RPC protocols permit synchronous calls.
In a similar vein, be aware that there is NO code blocking in Flex/FlashPlayer. "Modal" dialogs and Alert.show() are not truly modal, processing runs to the end of the function. You cannot use loops or timers or whatever. You must use events to handle this kind of functionality. Resistance is futile. Tracy ________________________________ From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Lex Sent: Tuesday, March 13, 2007 4:34 PM To: [email protected] Subject: Re: [flexcoders] Synchronous HTTPService possible? Need to verify edit inside of Edit Event.. Hi Shaun, Thanks for the note, I had found a workaround. It's too bad nonetheless, this seems a pretty serious oversight on Adobe's behalf. Every other framework I've ever worked with, include simple browser XHOR can be made to permit sync requests.. Onto the next stumbling block! Cheers. Alex ----- Original Message ----- From: shaun <mailto:[EMAIL PROTECTED]> To: [email protected] <mailto:[email protected]> Sent: Tuesday, March 13, 2007 5:03 PM Subject: Re: [flexcoders] Synchronous HTTPService possible? Need to verify edit inside of Edit Event.. Hi, Alex wrote: > Quick question, > > > I'm trying to devise a table-edit view of a set of database tables, > and am successfully pulling records using e4x etc. > > At the cell-edition stage, I'm capturing an "itemEditEnd" event on my > DataGrid, and that's going well also. > > My question however, surrounds actual edition, and the cancellation of > an edit event. > > The code should look like this: > > private function editHandler( e:DataGRidEvent ):void{ > if( e.reason == DataGridEventReason.CANCELLED ) > return; > > // get the new input > var newData:String = TextInput( > e.currentTarget.itemEditorInstance).text; > > // request the edit > ?? > > if( "edit was bad" ){ > e.preventDefault(); > // TextInput( dataGrid.itemEditorInstance ).errorString = "Invalid > input"; > } > } > > > "Requesting the edit" above, involves using HTTPService to send the edit > request to the server, which will respond with OK, or NOT OK. How can I > "wait" for an HTTPService request inside of that function, so that I can > call e.preventDefault() if required? AFAIK, the HTTPService only works > with a callback-type model? > > Can I synchronize and wait on a lock like in Java in this case? > No, I dont think you can do it like that. How about moving the "if (edit is bad)" check to the result handler of the http service. Then depending on whether you prevented the default event from happening or not in the itemEditEnd handler, update the value accordingly. It might look something like this: get the original value from the model. get the new value from the model. dispatch the validation http service event with the old and new value on result of the validation event if the result is NOT OK then set the data in the model back to the old value set the error message end if end on result I guess, depending on your architecture, you could just move your if("edit was bad" ){ } code into another method and have the component implement the IResponder interface to invoke that method when the validation service is done. Then again, there are validation classes that are probably the best place to do this rather than the itemEditEnd event handler - not sure. HTH. cheerio, shaun
