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Cant find proper method or idea how to...

 
 
Nevio
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      09-21-2008
Hi all.

Got 1 question and it's troubling me totally. I please someone to
answer me.

I'm building one project over php/javascript and it's not problem to
load practically anything but 1 thing is spending my nerves totally.

Question is:

Is it possible somehow to retrieve data in real time mode? I just
don't wan to use setTimeout or setInterval methods. Something like
data.onUpdate or something like that hehe

Thanks for helpin me out.

Cheers!
 
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SAM
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      09-21-2008
Nevio a écrit :
> Hi all.
>
> Got 1 question and it's troubling me totally. I please someone to
> answer me.
>
> I'm building one project over php/javascript and it's not problem to
> load practically anything but 1 thing is spending my nerves totally.
>
> Question is:
>
> Is it possible somehow to retrieve data in real time mode? I just
> don't wan to use setTimeout or setInterval methods. Something like
> data.onUpdate or something like that hehe
>
> Thanks for helpin me out.


and with some context ?

(when does the datas have to be updated ?
and where the new datas are ?
and where to display these last ones ?)

Ajax ?


Js :
====
var data = 'hello ';

html :
======
your name : <input on change="alert(data+this.value);">


--
sm
 
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Jorge
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      09-21-2008
On Sep 21, 12:23 pm, Nevio <(E-Mail Removed)> wrote:
>
> Question is:
>
> Is it possible somehow to retrieve data in real time mode? I just
> don't wan to use setTimeout or setInterval methods. Something like
> data.onUpdate or something like that hehe



Because a server can't initiate a transfer, one would initially think
that there's no way, but there is, yes, and a quite good one, in fact:

You just need to make sure that there's *always* a (one) pending XHR.
Upon entering (onload) of the page:

1.- Post the XHR that will receive the 'real time' data.
2.- This XHR will complete with either a timeout or because some 'real
time' data has arrived.
3.- Post inmediatly after completion ('2') another XHR (goto '1').

As you can see, whenever/if the server has some 'real time' data to
send to the client, it can do so through the currently open/pending
XHR.

The latest firefoxes can have up to six different, concurrent XHRs
ongoing, most other browsers can have up to 4. I don't know about IE,
though.
See http://preview.tinyurl.com/6mm5tm

--
Jorge.
 
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Joost Diepenmaat
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      09-21-2008
Jorge <(E-Mail Removed)> writes:

> On Sep 21, 12:23 pm, Nevio <(E-Mail Removed)> wrote:
>>
>> Question is:
>>
>> Is it possible somehow to retrieve data in real time mode? I just
>> don't wan to use setTimeout or setInterval methods. Something like
>> data.onUpdate or something like that hehe

>
>
> Because a server can't initiate a transfer, one would initially think
> that there's no way, but there is, yes, and a quite good one, in fact:
>
> You just need to make sure that there's *always* a (one) pending XHR.
> Upon entering (onload) of the page:
>
> 1.- Post the XHR that will receive the 'real time' data.
> 2.- This XHR will complete with either a timeout or because some 'real
> time' data has arrived.
> 3.- Post inmediatly after completion ('2') another XHR (goto '1').


Actually, you don't need XHR at all. It's easier to just push a <script>
tag to a hidden frame. That way, you don't need to repeat requests; you
just keep appending to a single reply (and you can do that from a
different server than your "main" page).

--
Joost Diepenmaat | blog: http://joost.zeekat.nl/ | work: http://zeekat.nl/
 
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Jorge
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      09-21-2008
On Sep 21, 10:23*pm, Joost Diepenmaat <(E-Mail Removed)> wrote:
>
> Actually, you don't need XHR at all. It's easier to just push a <script>
> tag to a hidden frame. That way, you don't need to repeat requests; you
> just keep appending to a single reply (and you can do that from a
> different server than your "main" page).
>


Sounds good, but I don't get it or I'm missing something: you request
a script, but it's not until it has been 'completely' received that it
executes (right?), it holds the wanted data, and it has to re-request
another script ?

If so, there are -as well- going to be multiple requests... or not ?

And what about security matters ? What if somebody manages to inject
one of his own scripts instead of yours ? Because one thing is getting
the wrong data and another different one is letting the door open to
code injection attacks.

--
Jorge.
 
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Nevio
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      09-21-2008
On Sep 21, 11:03*pm, Jorge <(E-Mail Removed)> wrote:
> On Sep 21, 10:23*pm, Joost Diepenmaat <(E-Mail Removed)> wrote:
>
>
>
> > Actually, you don't need XHR at all. It's easier to just push a <script>
> > tag to a hidden frame. That way, you don't need to repeat requests; you
> > just keep appending to a single reply (and you can do that from a
> > different server than your "main" page).

>
> Sounds good, but I don't get it or I'm missing something: you request
> a script, but it's not until it has been 'completely' received that it
> executes (right?), it holds the wanted data, and it has to re-request
> another script ?
>
> If so, there are -as well- going to be multiple requests... or not ?
>
> And what about security matters ? What if somebody manages to inject
> one of his own scripts instead of yours ? Because one thing is getting
> the wrong data and another different one is letting the door open to
> code injection attacks.
>
> --
> Jorge.


Oh... thanks guys for this! I will try to do it over pending XHR but
kinda
somehow i see flex ( AS ) as currently the best solution. I'm doing
some huge chat system
and kinda better is to just start with AS as I think. But for
notifiers and rest of it
ill use this pending XHR methods. Thanks Jorge and rest of you who
wanted to help me out.

I dun ever ever ever use iframe. If I need it, I use div instead lol.
That thing is old and full of security holes as I know.

Cheers
 
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