[Seaside] Asynchronous update from web server

[dtrussardi at tiscali.it]

Ciao,

	thanks.

> El lun., 8 abr. 2019 a las 7:48, dtrussardi at tiscali.it
> (<dtrussardi at tiscali.it>) escribió:
> 
>>        In my case i haven't any user actions on the client.
>>        The client display some data with dynamic banner ( marquee tag )
>>        and i need to update it only when the data to display change from the server.
>>        When the data on the server relative to an banner change i need to force the clients banners update.
>>        it seems to me that your initial solution may be fine.
>> 
>>        What do you think?
> 
> Too complex for such a simple task.
> 
> Is the <marquee> tag still a thing? I though it dissapeared when
> Geocities closed. :)
> 
> See below my suggestion.
> 
> 
>>        Another solution could be to manage an client ajax request with a specific interval
>>        but  update the relative  banner div  only if the related data received from the server changed.
>>                ( But how i can manage it?
>>                 Can i not reply to an client ajax request
>>                        or respond to doing nothing and continue to view the current status )
> 
> You can have a recursive call to setInterval() that returns a script
> (javascript) that updates the mentioned banner, and if no update is
> necessary you do nothing. Doing it once per minute is nothing for the
> server, since it's a simple AJAX call, which if nothing needs
> updating, is fast to answer.
> 
> These are the key parts:
> 
> renderContentOn: html
>  self renderBannerOn: html.
>  html script: (html jQuery script: [ :script | self scriptUpdaterOn: script ])
> 
> scriptUpdaterOn: aJSScript
>  aJSScript <<
>    ((aJSScript jQuery ajax
>      script: [ :s |
>        self shouldUpdate ifTrue: [ self scriptBannerUpdateOn: s ].
>        self scriptUpdaterOn: s ]) setTimeout: 1 minute)

	The setTimeout is not implemented in my system.

	With 	timeout:    i have some   problematic.

	I change the		 scriptUpdaterOn: aJSScript	to:

	scriptUpdaterOn: aJSScript
		aJSScript <
  			 ((aJSScript jQuery ajax
   			  script: [ :s |
       					self shouldUpdate ifTrue: [ self scriptBannerUpdateOn: s ].
			]) interval: 1 minute)

	It works very well relatively to my current needs.

	Dario

> 
> scriptBannerUpdateOn: s
>  s << ((s jQuery id: 'banner') replaceWith: [ :h | self renderBannerOn: h ])
> 
> Attached to this mails goes a working example of this.
> 
> In #scriptBannerUpdateOn: I would put all the logic, even by replacing
> the whole component as a whole (sometimes the best compromise) or
> indidividual elements within it).
> 
> 
> 
> Regards,
> 
> Esteban A. Maringolo
> <EAMRecursiveTimeout.st>_______________________________________________
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