Rails spinoffs - Jun 2006 - Global variables and onComplete in Ajax.Request

Hello everyone,

Just a note, I have to pass my JSON in the response body.  I''m aware
of the X-JSON header, but am passing too much data to use it.  No
problem and I have code that has it working well.

While I''m getting my JSON data back and can do whatever I''d
like with
it in "setMakeVars", I''d like to set it to a global var
"gljson"
below, but it never gets set.

Everything with the request is fine and there is data in the "json"
var in "setMakeVars", but it''s almost like
"setMakeVars" doesn''t have
access to global vars.

var gljson;
var url = ''/my/path/here'';
var ajobj = new Ajax.Request(
    url,
    {
        method: ''get'',
        onComplete: setMakeVars
    });

function setMakeVars (transport) {
   var json = eval(transport.responseText);
   gljson = json;
}

alert(gljson); // is undefined

Has anyone else run into this?  Any ideas what I can do to fix it?

Thanks for any help,
Kevin
-- 
Kevin Old
kevinold-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org

On 6/14/06, Kevin Old <kevinold-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
wrote:
> Hello everyone,
>
> Just a note, I have to pass my JSON in the response body.  I''m
aware
> of the X-JSON header, but am passing too much data to use it.  No
> problem and I have code that has it working well.
>
> While I''m getting my JSON data back and can do whatever
I''d like with
> it in "setMakeVars", I''d like to set it to a global var
"gljson"
> below, but it never gets set.
>
> Everything with the request is fine and there is data in the
"json"
> var in "setMakeVars", but it''s almost like
"setMakeVars" doesn''t have
> access to global vars.
>
> var gljson;
> var url = ''/my/path/here'';
> var ajobj = new Ajax.Request(
>     url,
>     {
>         method: ''get'',
>         onComplete: setMakeVars
>     });
>
> function setMakeVars (transport) {
>    var json = eval(transport.responseText);
>    gljson = json;
> }
>
> alert(gljson); // is undefined
>
Hi everyone,

I''ve figured out that my variable was being set with the JSON data,
but it was only "in scope" with the data inside the setMakeVars
function.  A friend said that in order to use this data I''d have to
make the subsequent calls from within setMakeVars.  I''m not sure
that''s a good idea.

Here''s what I''m trying to do.  I''m building a
multirecord (in place)
edit form and have a need for the Ajax.InPlaceSelect [1,2] lists.  It
needs the data in two arrays, one for the keys, the other the values.
Using the $H() function, I can do this, but since I plan to have 10
records per page (10 instances of the select list), it''d make sense to
fetch the data once and store it in a global variable, right?

Can this be done?

[1] http://dev.rubyonrails.org/attachment/ticket/2667/Ajax.InPlaceSelect.3.js
[2] http://wiki.script.aculo.us/scriptaculous/show/InPlaceSelect

Any help is greatly appreciated!
Kevin
-- 
Kevin Old
kevinold-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org

> > var gljson;
> > var url = ''/my/path/here'';
> > var ajobj = new Ajax.Request(
> >     url,
> >     {
> >         method: ''get'',
> >         onComplete: setMakeVars
> >     });
> >
> > function setMakeVars (transport) {
> >    var json = eval(transport.responseText);
> >    gljson = json;
> > }
> >
> > alert(gljson); // is undefined
> >
That alert is being called before the ajax request finishes (if you told
it to send it synchronously instead of asynchronously, it would wait
until it finished before it moved on to run the alert).

Test it like this:

var gljson;
var url = ''/my/path/here'';
var ajobj = new Ajax.Request(
    url,
    {
        method: ''get'',
        onComplete: setMakeVars
    });

function setMakeVars (transport) {
   var json = eval(transport.responseText);
   gljson = json;
   alert(json);
   testGlobal();
}

function testGlobal () {
   alert(gljson);
}

That should tell you if it is persisting.  The first alert lets you know
if the eval worked, then you call another function and alert the global
variable to see if it has a value.

Greg