Hi, I'm a bit concerned about Kevins comment above that the metadata servlet is 'intended to be consumed and processed serverside' ( despite the xhr example). I am also integrating shindig generated content into a purely client-side container. Is this a totally unforseen usage of the service ? The further comment that handling the chrome , iframe generation client-side is 'unwieldy, is pure opinion, Kevin, a javascript specialist (like myself) would see it quite the other way round. Can we be assured that the metadata service will always be available for client consumption, if not it will make shindig usage for client-side containers like my own impossible.
Steve On Tue, May 13, 2008 at 11:52 PM, Kevin Brown <[EMAIL PROTECTED]> wrote: > On Tue, May 13, 2008 at 2:58 PM, Tim Thelin <[EMAIL PROTECTED]> wrote: > > > Hi Erin, > > > > I have the same issue, and I solved it (mostly) client side. Now based on > > Kevin's response it doesn't sound like what I'm about to say is the > > correct > > way, but it does work. > > > > I used jsonp as the vehicle for getting the data instead of a raw XHR, as > > jsonp lets you get json-data cross-origin: > > http://ajaxian.com/archives/jsonp-json-with-padding > > > > The idea is to dynamically create a script tag pointing to /metadata, and > > you add query parameters to specify (1) the data you want back, and (2) > > the > > callback function you want called with the new json-formatted-metadata > > > > The only problem was that script tags get the scripts using GET, not POST, > > and /metadata expects a POST. So I also modified the shindig gadget > > server > > to accept a GET to /metadata, making it do the same exact thing as the > > POST > > except to expect the args in the query params instead of post data, and to > > honor the jsonp callback. > > > > > > Kevin, > > > > Besides latency, is there anything inherently wrong with doing it this > > way? > > > The biggest problem is that the metadata request will likely contain more > than 2KB of data for any page with a significant number of gadgets (or user > preferences), and JSONP won't work for GET requests that need more than > that. > > This approach also requires you to do all of the gadget "chrome" and iframe > generation in javascript, which is unwieldy compared to server-side > templating solutions like PHP or whatnot. > > > > > > > > > > -Tim > > > > On Tue, May 13, 2008 at 2:48 PM, Kevin Brown <[EMAIL PROTECTED]> wrote: > > > > > On Tue, May 13, 2008 at 2:38 PM, Erin Hoffmann <[EMAIL PROTECTED]> > > > wrote: > > > > > > > Hello, > > > > > > > > I am trying to understand better how to use the gadget metadata > > service. > > > > I > > > > want to invoke the metadata service from my container page in order to > > > > fetch > > > > the user preference metadata and the gadget default title. Looking at > > > > sample-metadata.html and RpcServlet.java, it appears that the only way > > > to > > > > request metadata is via an XHR post. This means the request needs to > > > > originate from the same domain the gadget server is on. > > > > > > > > Unfortunately, my container page is on a different domain than my > > gadget > > > > server. Can anyone provide me some guidance as to how to do what I > > want > > > > to > > > > do? Invoking the metadata service from within the gadget iframe > > doesn't > > > > make a lot of sense from a lot of different perspectives. Invoking it > > > > from > > > > the container is currently impossible when the container and gadget > > > server > > > > are on different domains. > > > > > > > > Am I thinking about this the right way? Any help is appreciated. > > > > > > > > > The metadata servlet is intended to be consumed and processed > > server-side, > > > before you emit your output html. The sample page uses XHR in order to > > > remain implementation neutral. If your parent page was in PHP, you could > > > do > > > something like the following: > > > > > > $request = json_encode('gadgets'=>array('...'), > > 'context'=>array('...')); > > > $curl = curl_init(); > > > ...various curl setup operations... > > > $data = json_decode(curl_exec($curl)); > > > > > > foreach ($data['gadgets'] as $gadget) { > > > echo '<h2>'.htmlentities($gadget['title']).'</h2>'; > > > echo '<iframe src="... > > > } > > > > > > Similar techniques can be used in python, perl, ruby, java, or whatever > > > language you like. I'd definitely not recommend doing this client side, > > if > > > for nothing else than to avoid additional end-user latency. > > > > > > > > > > > > > > Thanks, > > > > Erin > > > > > > > > > >
