Re: [Geoserver-users] How to use GeoServer REST GET requests in JavaScript?

[Milton J. <mi...@te...>]

Hey Justin.

Hmm, well, mysteries of the web..?

About the issue of reaching GeoServer even though the response didn't 
get to JavaScript: I just found out that it happens even when the script 
is on a different host altogether! So, it seems that the same origin 
policy blocks only the response... Weird, great security, heh? I guess 
one can just go and do all the PUTS he wants then.. :P

Cheers
Milton

Justin Deoliveira wrote:
> On 3/17/10 11:26 AM, Milton Jonathan wrote:
>> Hi Justin
>>
>> Thanks for coming in!
>>
>> I've found out: yes, it WAS the same origin policy.. But now I AM 
>> confused.
>>
>> First thing: thanks a LOT for stating that I had to put it in the www
>> directory. I had put it originally directly in the "webapps/geoserver",
>> and it WAS accessible via http:localhost:8080/geoserver/myscript.html.
>> So how would one know what's the path for the "right origin"?
> 
> Afaik same origin applies to the host + port portion of the url. So I 
> guess this should have been the same origin. Perhaps it had something to 
> do with the location.
>>
>> Second thing, and this is what most confuses me: the request WAS going
>> all the way to GeoServer and being processed! How come? Is the same
>> origin policy only applied for issuing the response?? I thought it
>> should have prevented the request from ever reaching the REST service
>> code..
> Good question. I actually don't know how browsers enforce this policy. A 
> javascript devel would know the answer. But it might have something to 
> do with the fact that your resource was actually hitting the same origin 
> (since your page is beign served up from webapps/geoserver).
> 
>>
>> Anyway, thanks a ton. I see now that the OpenLayers WFS layer I never
>> got to work is also fine (I'm still having problems setting up the
>> proxy.cgi here on Windows, maybe it's a Python problem).
>>
>> Cheers
>> Milton
>>
>>
>> Justin Deoliveira wrote:
>>> Hi Milton,
>>>
>>> Where are you serving the javascript from? The same origin policy will
>>> apply for content accessed via the REST api. You need to ensure that
>>> your javascript is being served by geoServer (www directory) or that
>>> you are proxying for geoserver on the same host that is serving your
>>> javascript.
>>>
>>> You may also find the following of interest:
>>>
>>> http://svn.codehaus.org/geoserver/trunk/src/extension/restconfig/src/client/javascript/lib/ 
>>>
>>>
>>>
>>> It was a javascript REST api that was started but never got finished.
>>>
>>> -Justin
>>>
>>>
>>> On 3/17/10 10:12 AM, Milton Jonathan wrote:
>>>> Hey there
>>>>
>>>> This is not exactly a GeoServer issue, but I thought you guys might 
>>>> tell
>>>> me if I'm on the wrong path (probably the case).
>>>>
>>>> I've recently tried to use GeoServer's REST API in JavaScript but could
>>>> not get any GET requests to work. REST is in place and working: if I
>>>> type "http://localhost:8080/geoserver/rest/layers" in the browser, it
>>>> works and I get the list of layers in the server. Using CURL also works
>>>> fine.
>>>>
>>>> However, when trying to use JavaScript, I never get these GET requests
>>>> to work: the response theat arrives in JavaScript always has an empty
>>>> response.responseText and a null response.responseXml. But its status
>>>> is OK!
>>>>
>>>> I tried both using OpenLayers.Request.GET and directly using
>>>> XMLHttpRequest. In both cases, I can see that the request arrives at
>>>> GeoServer and is processed fine (I've put a breakpoint in GeoServer's
>>>> code to make sure), so there's no proxy-like issue here (and after all,
>>>> it's all running on localhost).
>>>>
>>>> So, what am I missing? It seems that the problem is to get 
>>>> JavaScript to
>>>> correctly parse or understand the request's response. I always thought
>>>> that this kind of REST API was especially relevant for use in
>>>> JavaScript, but I keep scratching my head about how people use it.
>>>> Should I simply not do this? Is there another way to do this request 
>>>> and
>>>> get the response into JavaScript?
>>>>
>>>> Here's the code for the request using OpenLayers.Request:
>>>>
>>>> var request = OpenLayers.Request.GET({
>>>> url: "http://localhost:8080/geoserver/rest/layers",
>>>> callback: handler
>>>> });
>>>>
>>>> function handler(request) {
>>>> alert('responseXML: ' + request.responseXML);
>>>> alert('responseText: ' + request.responseText);
>>>> alert('status: ' + request.statusText);
>>>> }
>>>>
>>>>
>>>> And here's the code for the request using XMLHttpRequest:
>>>>
>>>> var xmlhttp = new XMLHttpRequest();
>>>> xmlhttp.open("GET",
>>>> "http://localhost:8080/geoserver/rest/layers",true);
>>>> xmlhttp.onreadystatechange=function() {
>>>> if (xmlhttp.readyState==4) {
>>>> alert('responseXML: ' + request.responseXML);
>>>> alert('responseText: ' + request.responseText);
>>>> alert('status: ' + request.statusText);
>>>> }
>>>> }
>>>> xmlhttp.send();
>>>>
>>>> In both cases, results are:
>>>> responseXML: null
>>>> responseText:
>>>> status: OK
>>>>
>>>>
>>>> Thanks for all
>>>> Milton
>>>>
>>>
>>>
>>
> 
> 

-- 

Milton Jonathan
Grupo GIS e Meio Ambiente
Tecgraf/PUC-Rio
Tel: +55-21-3527-2502