UX - List control - "conditionally" refresh data ?

[cemopolat]

Hi,

I have a UX components showing list of "Log Records" - date descending order.
I enabled timer for UX and refreshing the list data every 5 seconds.
I want to be able to refresh the data "only if there is a new record" or in other words "if list item count changes".
Otherwise it doesn't make sense (no change but continously refreshing screen)

I read "beforeontimer" description but I have no idea how to get record count of a list and "return" a boolean from it.
And I am not sure why we don't use "if then" statement in "onTimer" event instead of using "beforeOntimer".

Any help will be greatly appreciated..

Regards..

Cemo

[mixter]

Re: UX - List control - "conditionally" refresh data ?

One way to do this would be use Action Javascript and create an AJAX Callback that runs some XBasic which executes a query or stored procedure which does a row count on your log table, and outputs the single number back to javascript.

in your ontimer event, use RunAction to call the name of the Action Javascript AJAX Callback function to return the row count number into a javascript variable

{dialog.object}.runAction('NameOfMyActionJavascript');

(assumes the "NameOfMyActionJavascript" callback above is returning some JavaScript that is setting a JavaScript variable to the value returned by your row count stored procedure)


Then compare the number returned from the callback, with the previous number returned the time before

if the two numbers are different, do a list refresh in your UX

[cemopolat]

Re: UX - List control - "conditionally" refresh data ?

Hi Michael,

I was thinking there should be a more efficient way at client side, because we can put the list item count on the UX easily. So the data should be already there.

Unfortunately I have nearly no idea how to return / compare values in Java script.
Currently I am trying to understand how to pass values between Xbasic / JS and server side / client side and such basic things..

Could you please give me a little bit more detail, or sample code ?
For example, where should I store the "previous record count" to compare it to new values later on ?

Thanks in advance ..

Cemo

One way to do this would be use Action Javascript and create an AJAX Callback that runs some XBasic which executes a query or stored procedure which does a row count on your log table, and outputs the single number back to javascript.

in your ontimer event, use RunAction to call the name of the Action Javascript AJAX Callback function to return the row count number into a javascript variable

{dialog.object}.runAction('NameOfMyActionJavascript');

(assumes the "NameOfMyActionJavascript" callback above is returning some JavaScript that is setting a JavaScript variable to the value returned by your row count stored procedure)


Then compare the number returned from the callback, with the previous number returned the time before

if the two numbers are different, do a list refresh in your UX

[mixter]

Re: UX - List control - "conditionally" refresh data ?

we can put the list item count on the UX easily

you can store the current/previous values of List Count in either State Variables or maybe even using a hidden Textboxes on your UX

how to pass values between Xbasic / JS and server side / client side and such basic things..

State Variables are one way to pass values between client side and server side (State Variables are available to use in your code on both the server side XBasic and the client side JavsScript)

Another more immediate way is by creating an AJAX callback, which is JavaScript on the client calling an XBasic function on the server, and the XBasic function can return any amount of JavaScript back to the browser again.

You might also like to use executeThisThenThat to ensure that you know exactly what sequence the JavaScript side is executing parts of your code (split them into separate functions and use ExecuteThisThenThat to specify exact order things will run in (otherwise you might be surprised...!)

See this thread here
http://msgboard.alphasoftware.com/al...d.php?110895#5

which shows a few things like executeThisThenThat

and setting a State Variable (on the JavaScript side)

var obj= {daysheet: IDAYSHEET};
{dialog.object}.setStateInfo(obj);

using runAction to execute a Javascript Action by it's name,
The Javascript Action was created as an AJAX callback (which therefore runs some XBasic on the server side)

{dialog.object}.runAction('runSPtoCreateTimesheetRecordsUsingDaysheetID');

Also, another way to find more relevant information on using XBasic to and from JavaScript the client side,
search for "callback" on Alpha's youtube channel
http://www.youtube.com/user/AlphaSof...query=callback

and using state variables in JavaScript and XBasic
http://www.youtube.com/user/AlphaSof...ch?query=state

[cemopolat]

Re: UX - List control - "conditionally" refresh data ?

Michael,

Thank you very much for your detailed answer.
I think the key is to use "state variables"
I will go that way.

regards..

Cemo