Implement AJAX in App Engine

[Shay Ben Dov]

I wonder is there a way to implement AJAX in an application like the
easy way it is done in Rails:

you write 1 line in the header to include Javascript, defaults and
other

then you issue a simple command in your HTML body like:

<div id="alerts">

</div>
<%= periodically_call_remote(:update => 'alerts',
:url => { :controller => :alerts,
:action => :listen_for_requests },
:frequency => 10 )%>
to issue a call to the server in the background.

Enabling this kind of capabilities will make life easier and speed-up
development

[David Symonds]

On Sun, Oct 12, 2008 at 7:06 PM, Shay Ben Dov <shay....@gmail.com> wrote:

> I wonder is there a way to implement AJAX in an application like the
> easy way it is done in Rails:
>
> you write 1 line in the header to include Javascript, defaults and
> other
>
> then you issue a simple command in your HTML body like:

App Engine is really a much lower level platform than that. You could
probably write your own AJAX stuff like you suggest using JavaScript,
being helped out by a library like jQuery.

Dave.

[Shay Ben Dov]

If you can point to RIA source code that updates continuously the time
or the status of inventory levels

It will be very helpful

thanks

Shay Ben Dov


On Oct 13, 9:21 pm, Davide Rognoni <davide.rogn...@gmail.com> wrote:
> "Ajax Requests"http://docs.jquery.com/Ajax
>
> "setInterval(func, interval, [args])"
> Calls the specified "func" (or aJavaScriptstatement) repeatedly per
> the "interval" interval, in milliseconds (ie: 1000=every 1 second).
> "func" must be surrounded in quotations, as if it was a string. Use
> the optional "args" to pass any number of arguments to the function.http://www.javascriptkit.com/jsref/window.shtml
>
> On Oct 13, 1:00 pm, "David Symonds" <dsymo...@gmail.com> wrote:

[Bill]

There are at least two things you'd want to do in your case:

1) Figure out the necessary javascript to periodically issue AJAX
calls. This will be dependent on the javascript framework (if any)
you chose.

2) Setup a Django template helper to insert that javascript when the
App Engine server parses your template file. See this cookbook
recipe:
http://appengine-cookbook.appspot.com/recipe/using-custom-django-template-helpers/?id=ahJhcHBlbmdpbmUtY29va2Jvb2tyjgELEgtSZWNpcGVJbmRleCI4YWhKaGNIQmxibWRwYm1VdFkyOXZhMkp2YjJ0eUZBc1NDRU5oZEdWbmIzSjVJZ1pFYW1GdVoyOE0MCxIGUmVjaXBlIjlhaEpoY0hCbGJtZHBibVV0WTI5dmEySnZiMnR5RkFzU0NFTmhkR1ZuYjNKNUlnWkVhbUZ1WjI4TTAM

A lengthy intro to template helpers is here:
http://docs.djangoproject.com/en/dev/howto/custom-template-tags/

And I recently discovered these rails helpers but haven't used them
yet:
http://code.google.com/p/django-helpers/

-Bill

[Shay Ben Dov]

Thanks for the tip.

I've developed what I've intended. I used the following:

function functionName(){

new new Ajax.Updater('div id', '/action_name', {
method: 'get'

});

}

setInterval("functionName()", 3000)

When the application will be ready I'll let you know

Again thanks

Shay Ben Dov

On Oct 13, 9:21 pm, Davide Rognoni <davide.rogn...@gmail.com> wrote:
> "Ajax Requests"http://docs.jquery.com/Ajax
>
> "setInterval(func, interval, [args])"

> Calls the specified "func" (or a JavaScript statement) repeatedly per

> the "interval" interval, in milliseconds (ie: 1000=every 1 second).
> "func" must be surrounded in quotations, as if it was a string. Use
> the optional "args" to pass any number of arguments to the function.http://www.javascriptkit.com/jsref/window.shtml
>
> On Oct 13, 1:00 pm, "David Symonds" <dsymo...@gmail.com> wrote:
>

[Shay Ben Dov]

The method I used doesn't work on IE 6.

If someone can verify that it works on IE 7 I'm not using it

or if I can get a guidance to make it compatible with IE it will be
excellent.

The reference I used is: http://www.tutorialized.com/view/tutorial/Prototype-and-AJAX-Tutorial/35281

The example is working on IE 6 the problem is probably with
setInterval

On Oct 13, 9:21 pm, Davide Rognoni <davide.rogn...@gmail.com> wrote:
> "Ajax Requests"http://docs.jquery.com/Ajax
>
> "setInterval(func, interval, [args])"
> Calls the specified "func" (or a JavaScript statement) repeatedly per
> the "interval" interval, in milliseconds (ie: 1000=every 1 second).
> "func" must be surrounded in quotations, as if it was a string. Use
> the optional "args" to pass any number of arguments to the function.http://www.javascriptkit.com/jsref/window.shtml
>
> On Oct 13, 1:00 pm, "David Symonds" <dsymo...@gmail.com> wrote:
>

[Shay Ben Dov]

************ sorry in the example I made a mistake:

It should be 1 new and not

new new Ajax.Updater('div id', '/action_name', {

now on IE 6 we don't get an error message
but it is not doing the ajax stuff with the setInterval

on Chrome Firefox and Flock it is working fine.

On Oct 25, 3:08 am, Shay Ben Dov <shay.ben...@gmail.com> wrote:
> The method I used doesn't work on IE 6.
>
> If someone can verify that it works on IE 7 I'm not using it
>
> or if I can get a guidance to make it compatible with IE it will be
> excellent.
>

> The reference I used is:http://www.tutorialized.com/view/tutorial/Prototype-and-AJAX-Tutorial...

[Arun Shanker Prasad]

Hi,
Have you tried setTimeout()? It does the same thing and it works for
me in most ie versions.

[Shay Ben Dov]

Thanks but to master GWT is not a joy.

I think part of the problem is related to CSS compatibility issues in
IE 6 you can spot that the program span <div but doesn't show the data
written by the program.

Anyhow CSS differences is also a complicated issue.

Any guidance is appreciated.

Shay Ben Dov


On Oct 25, 1:43 pm, RIAgallery <davide.rogn...@gmail.com> wrote:
> I think the best way will be:
>
> "Google Web Toolkit 1.5"http://code.google.com/docreader/#p=google-web-toolkit-doc-1-5
>
> Enjoy ;-)

[Shay Ben Dov]

Hi,

The ajax implementation works on IE 6 when I access my application on
the GAE and not on the dev_appserver.py

probably timing problem on the dev pc whenever I was trying to run 2-3
different browsers on the same pc including IE.

Thanks for the help from all of you.

The application http://cmyquest.appspot.com

See you all

Shay Ben Dov