/**
* Render the gadget into a string by performing the following steps:
*
* - Retrieve gadget specification information (GadgetSpec, MessageBundle, etc.)
*
* - Fetch any preloaded data needed to handle the request, as handled by Preloader.
*
* - Perform rewriting operations on the output content, handled by Rewriter.
*
* @param gadget The gadget for the rendering operation.
* @return The rendered gadget content
* @throws RenderingException if any issues arise that prevent rendering.
*/
public String render(Gadget gadget)
{
try
{
View view = gadget.getCurrentView();
GadgetContext context = gadget.getContext();
GadgetSpec spec = gadget.getSpec();
IPreloads preloads = preloader.preload(context, spec,
PreloaderService.PreloadPhase.HTML_RENDER);
gadget.setPreloads(preloads);
String content;
if (view.getHref() == null)
{
content = view.getContent();
}
else
{
// TODO: Add current url to GadgetContext to support transitive proxying.
UriBuilder uri = new UriBuilder(view.getHref());
uri.addQueryParameter("lang", context.getLocale().getLanguage());
uri.addQueryParameter("country", context.getLocale().getCountry());
sRequest request = new sRequest(uri.toUri())
.setIgnoreCache(context.getIgnoreCache())
.setOAuthArguments(new OAuthArguments(view))
.setAuthType(view.getAuthType())
.setSecurityToken(context.getToken())
.setContainer(context.getContainer())
.setGadget(spec.getUrl());
sResponse response = DefaultHttpCache.Instance.getResponse(request);
if (response == null || response.isStale())
{
sRequest proxyRequest = createPipelinedProxyRequest(gadget, request);
response = requestPipeline.execute(proxyRequest);
DefaultHttpCache.Instance.addResponse(request, response);
}
if (response.isError())
{
throw new RenderingException("Unable to reach remote host. HTTP status " +
response.getHttpStatusCode());
}
content = response.responseString;
}
return(rewriter.rewriteGadget(gadget, content));
}
catch (GadgetException e)
{
throw new RenderingException(e.Message, e);
}
}
/**
* Injects preloads into the gadget output.
*
* If preloading fails for any reason, we just output an empty object.
*/
private static void InjectPreloads(Gadget gadget, Node scriptTag)
{
IPreloads preloads = gadget.getPreloads();
Dictionary <String, Object> preload = new Dictionary <string, object>();
foreach (PreloadedData preloaded in preloads.getData())
{
foreach (var entry in preloaded.toJson())
{
preload.Add(entry.Key, entry.Value);
}
}
Text text = scriptTag.getOwnerDocument().createTextNode("gadgets.io.preloaded_=");
text.appendData(JsonConvert.ExportToString(preload));
text.appendData(";");
scriptTag.appendChild(text);
}
/**
* Creates a proxy request by fetching pipelined data and adding it to an existing request.
*
*/
private sRequest createPipelinedProxyRequest(Gadget gadget, sRequest original)
{
sRequest request = new sRequest(original);
request.setIgnoreCache(true);
GadgetSpec spec = gadget.getSpec();
GadgetContext context = gadget.getContext();
IPreloads proxyPreloads = preloader.preload(context, spec,
PreloaderService.PreloadPhase.PROXY_FETCH);
// TODO: Add current url to GadgetContext to support transitive proxying.
// POST any preloaded content
if ((proxyPreloads != null) && proxyPreloads.getData().Count != 0)
{
JsonArray array = new JsonArray();
foreach (PreloadedData preload in proxyPreloads.getData())
{
Dictionary <String, Object> dataMap = preload.toJson();
foreach (var entry in dataMap)
{
// TODO: the existing, supported content is JSONObjects that contain the
// key already. Discarding the key is odd.
array.Put(entry.Value);
}
}
String postContent = array.ToString();
// POST the preloaded content, with a method override of GET
// to enable caching
request.setMethod("POST")
.setPostBody(Encoding.UTF8.GetBytes(postContent))
.setHeader("Content-Type", "text/json;charset=utf-8");
}
return(request);
}
/**
* @param preloads The preloads for the gadget that is being processed.
*/
public Gadget setPreloads(IPreloads preloads)
{
this.preloads = preloads;
return this;
}
/**
* @param preloads The preloads for the gadget that is being processed.
*/
public Gadget setPreloads(IPreloads preloads)
{
this.preloads = preloads;
return(this);
}
