JSON only...

[Alberto Santini]

Hello.

I would like to use Rpad (with Yahoo! User Interface - yui) as data
server provider. I would not use Rpad to embed R code in html pages,
but the Rpad server side would provide "only" the data requested from
the frontend in json format.

I am aware about json function in Rpad package and I played with Rpad
examples. Until here there is no problem.

I have been looking for a simple example about "R_process.pl" url
(post option) or "rpad.send" javascript snippet: how to re-use Rpad
framework without the high level Dojo tagging?

(I have been using the local version on Windows Vista).

Thanks in advance for your help,
Alberto

[Alberto Santini]

I found this way (using the local server on Windows Box):

http://127.0.0.1:8079/R_process.pl?&&command=R_commands&R_commands=print("hello")

returning

[1] "hello"

Of course R_commands may contain any R command or user function.
By the way in GET mode, as above, you have to encode the (complex)
params, but I will use post mode.

To receive the result in json format

...&R_commands=json(...what_you_wish...)

Or I could embed the trasformation to json format in the function I am
calling.

The pseudo-sequence diagram for that call, after you started Rpad
server with "Rpad()" is the following:
- mini1.1.tcl - see the line R_eval "processRpadCommands" in the
section R_process.pl
- LocalVersion.R - processRpadCommands() - guiSource(textcommands)
executes the commands

What I don't understand it is the double ampersand in the url: .../
R_process.pl?&&command=...

Next step it's the integration (using that template url as action of a
form, for instance) with YUI.
(I have to check too the passing of the arguments to the user
function).

Thanks in advance,
Alberto

[Short, Tom]

I don't know why you need the double ampersand. Likely a bug.

Tom Short
Electric Power Research Institute (EPRI)

[Alberto Santini]

Hello Tom.

Yes, my fault. We can delete the double ampersand. :) Of course I was
sleeping.

And below the snippet to use a json object returned by R using YUI.
Mission accomplished.

<script type="text/javascript">
YAHOO.util.Event.addListener(window, "load", function() {
YAHOO.example.XHR_JSON = new function() {
var myColumnDefs = [
{key:"a", label:"Col1"},
{key:"b", label:"Col2"},
{key:"c", label:"Col3"}
];

this.myDataSource = new YAHOO.util.DataSource("http://
127.0.0.1:8079/R_process.pl?");
this.myDataSource.connMethodPost = true;
this.myDataSource.responseType =
YAHOO.util.DataSource.TYPE_JSON;
this.myDataSource.responseSchema = {
fields: ["a","b","c"]
};

var args = encodeURIComponent("json(c(a=1, b=5, c=10))");
var postData = "command=R_commands&R_commands=" + args;
this.myDataTable = new YAHOO.widget.DataTable("json",
myColumnDefs, this.myDataSource,
{ caption:"",
draggableColumns:true,
selectionMode:"single",
initialRequest: postData
});

};
});
</script>

On Apr 8, 2:35 pm, "Short, Tom" <TSh...@epri.com> wrote:
> I don't know why you need the double ampersand. Likely a bug.
>
> Tom Short
> Electric Power Research Institute (EPRI)
>

Thanks Tom for your beautiful package.

Regards,
Alberto