public override bool Render(IInternalContextAdapter context, TextWriter writer, INode node)
{
IEngineContext railsContext = EngineContextLocator.Instance.LocateCurrentContext();
IViewComponentRegistry registry = railsContext.Services.GetService<IViewComponentFactory>().Registry;
IViewComponentDescriptorProvider viewDescProvider =
railsContext.Services.GetService<IViewComponentDescriptorProvider>();
ICacheProvider cacheProvider = railsContext.Services.CacheProvider;
INode compNameNode = node.GetChild(0);
if (compNameNode == null)
{
String message = String.Format("You must specify the component name on the #{0} directive", Name);
throw new ViewComponentException(message);
}
string componentName = compNameNode.FirstToken.Image;
if (componentName == null)
{
String message = String.Format("Could not obtain component name from the #{0} directive", Name);
throw new ViewComponentException(message);
}
if (componentName.StartsWith("$"))
{
String nodeContent = compNameNode.Literal.Trim('"', '\'');
SimpleNode inlineNode = runtimeServices.Parse(new StringReader(nodeContent), context.CurrentTemplateName, false);
inlineNode.Init(context, runtimeServices);
componentName = (string) Evaluate(inlineNode, context);
}
IDictionary componentParams = CreateParameters(context, node);
Type viewComptype = registry.GetViewComponent(componentName);
ViewComponentDescriptor descriptor = null;
CacheKey key = null;
if (viewComptype != null)
{
descriptor = viewDescProvider.Collect(viewComptype);
}
bool isOutputtingToCache = false;
ViewComponentCacheBag bag = null;
if (descriptor != null && descriptor.IsCacheable)
{
key = descriptor.CacheKeyGenerator.Create(componentName, componentParams, railsContext);
if (key != null)
{
ViewComponentCacheBag cachedContent = (ViewComponentCacheBag) cacheProvider.Get(key.ToString());
if (cachedContent != null)
{
// Restore entries
foreach(KeyValuePair<string, object> pair in cachedContent.ContextEntries)
{
context[pair.Key] = pair.Value;
}
// Render from cache
writer.Write(cachedContent.Content);
return true;
}
isOutputtingToCache = true;
bag = new ViewComponentCacheBag();
}
}
ViewComponent component = viewComponentFactory.Create(componentName);
if (component == null)
{
throw new MonoRailException("ViewComponentFactory returned a null ViewComponent for " + componentName + ". " +
"Please investigate the implementation: " + viewComponentFactory.GetType().FullName);
}
try
{
ASTDirective directiveNode = (ASTDirective) node;
IViewRenderer renderer = (IViewRenderer) directiveNode.Directive;
NVelocityViewContextAdapter contextAdapter = new NVelocityViewContextAdapter(componentName, node, viewEngine, renderer);
contextAdapter.Context = isOutputtingToCache ? new CacheAwareContext(context, bag) : context;
INode bodyNode = null;
if (node.ChildrenCount > 0)
{
bodyNode = node.GetChild(node.ChildrenCount - 1);
}
TextWriter output = isOutputtingToCache ? bag.CacheWriter : writer;
contextAdapter.BodyNode = bodyNode;
contextAdapter.ComponentParams = componentParams;
contextAdapter.TextWriter = output;
component.Init(railsContext, contextAdapter);
ProcessSubSections(component, contextAdapter);
const string ViewComponentContextKey = "viewcomponent";
object previousComp = context[ViewComponentContextKey];
try
{
context[ViewComponentContextKey] = component;
component.Render();
if (contextAdapter.ViewToRender != null)
{
RenderComponentView(context, contextAdapter.ViewToRender, output, contextAdapter);
}
if (isOutputtingToCache)
{
// Save output
cacheProvider.Store(key.ToString(), bag);
// Output to correct writer
writer.Write(bag.Content);
}
}
finally
{
if (previousComp != null)
{
context[ViewComponentContextKey] = previousComp;
}
else
{
context.Remove(ViewComponentContextKey);
}
}
}
finally
{
viewComponentFactory.Release(component);
}
return true;
}
public CacheAwareContext(IInternalContextAdapter context, ViewComponentCacheBag bag)
{
this.context = context;
this.bag = bag;
}