/// <summary>
/// 尝试获取缓存的输出
/// </summary>
/// <returns>缓存的输出</returns>
protected virtual ICachedResponse ResolveCache(string virtualPath)
{
var policy = HtmlServices.GetCachePolicy(HttpContext);
if (policy == null)
{
return(null);
}
CachePolicy = policy;
var clientCachePolicy = policy as IClientCacheablePolicy;
if (clientCachePolicy != null)
{
var response = clientCachePolicy.ResolveClientCache();
if (response != null)
{
return(response);
}
}
return(CachePolicy.ResolveCache());
}
/// <summary>
/// 加载 HTML 文档
/// </summary>
/// <param name="virtualPath">文档的虚拟路径</param>
/// <param name="cacheDependency">若文档已被缓存，获取缓存依赖项</param>
/// <returns>HTML 文档对象</returns>
public static IHtmlDocument LoadDocument(string virtualPath, out CacheDependency cacheDependency)
{
string cacheKey;
var result = LoadDocument(virtualPath, out cacheKey);
if (result == null)
{
cacheDependency = null;
return(result);
}
if (cacheKey != null)
{
cacheDependency = new CacheDependency(new string[0], new string[] { cacheKey });
}
else
{
cacheDependency = HtmlServices.CreateCacheDependency(virtualPath);
}
return(result);
}
/// <summary>
/// 渲染部分视图
/// </summary>
/// <param name="context">当前 HTTP 请求上下文</param>
/// <param name="virtualPath">部分视图的虚拟路径</param>
/// <returns>渲染结果</returns>
public static string RenderPartial(HttpContextBase context, string virtualPath)
{
var handler = HtmlHandlerProvider.GetHandler(virtualPath);
if (handler == null)
{
return(HtmlServices.LoadContent(virtualPath).Content);
}
var partialHandler = new JumonyPartialHandler();
return(partialHandler.RenderPartial(context, virtualPath, handler));
}
private static Uri CreateDocumentUri(string virtualPath)
{
if (virtualPath == null)
{
throw new ArgumentNullException("virtualPath");
}
if (!VirtualPathUtility.IsAppRelative(virtualPath))
{
throw HtmlServices.VirtualPathFormatError("virtualPath");
}
return(new Uri(baseUri, VirtualPathUtility.ToAbsolute(virtualPath)));
}
/// <summary>
/// 派生类可以重写此方法自定义加载虚拟路径处的文档的逻辑
/// </summary>
/// <returns></returns>
protected virtual IHtmlDocument LoadDocument(string virtualPath, out CacheDependency cacheDependency)
{
string cacheKey;
var document = HtmlServices.LoadDocument(virtualPath, out cacheKey);
if (cacheKey != null)
{
cacheDependency = new CacheDependency(new string[0], new string[] { cacheKey });
}
else
{
cacheDependency = HtmlServices.CreateCacheDependency(virtualPath);
}
return(document);
}
/// <summary>
/// 在 HTML 文档中查找 ViewHandler 路径设置。
/// </summary>
/// <param name="virtualPath">要处理的 HTML 文档的虚拟路径</param>
/// <returns>用于处理 HTML 的视图处理程序路径</returns>
public static string GetHandlerPath(string virtualPath)
{
var cacheKey = handlerPathCachePrefix + virtualPath;
var cacheItem = HttpRuntime.Cache.Get(cacheKey) as HandlerPathCacheItem;
if (cacheItem == null)
{
string cacheDependencyKey;
var document = HtmlServices.LoadDocument(virtualPath, out cacheDependencyKey);
if (document == null)
{
return(null);
}
var head = document.FindFirstOrDefault("head");
if (head == null)
{
return(null);
}
var handlerMeta = head.FindFirstOrDefault("meta[name=handler]");
if (handlerMeta == null)
{
return(null);
}
var handlerPath = handlerMeta.Attribute("value").Value();
if (cacheDependencyKey != null)
{
cacheItem = new HandlerPathCacheItem()
{
HandlerPath = handlerPath
};
HttpRuntime.Cache.Insert(cacheKey, cacheItem, new CacheDependency(new string[0], new[] { cacheDependencyKey }));
}
}
return(cacheItem.HandlerPath);
}
/// <summary>
/// 派生类重写此方法自定义加载文档的逻辑
/// </summary>
/// <param name="virtualPath">文档的虚拟路径</param>
/// <returns>加载的文档对象</returns>
protected virtual IHtmlDocument LoadDocument(string virtualPath)
{
IHtmlDocument document;
Trace("Begin load document.");
document = HtmlServices.LoadDocument(virtualPath);
if (document == null)
{
throw new HttpException(404, "加载文档失败");
}
Trace("End load document.");
return(document);
}
/// <summary>
/// 利用指定 VirtualPathProvider 将虚拟路径所指向文件当作静态文件加载。
/// </summary>
/// <param name="provider">指定的 VirtualPathProvider</param>
/// <param name="virtualPath">虚拟路径</param>
/// <returns>加载结果</returns>
public HtmlContentResult LoadContent(VirtualPathProvider provider, string virtualPath)
{
if (!VirtualPathUtility.IsAppRelative(virtualPath))
{
return(null);
}
if (!provider.FileExists(virtualPath))
{
return(null);
}
var file = provider.GetFile(virtualPath);
if (file == null)
{
return(null);
}
var key = provider.GetCacheKey(virtualPath) ?? "StaticFile_" + virtualPath;
var content = HttpRuntime.Cache.Get(key) as string;
if (content == null)
{
var dependency = HtmlServices.CreateCacheDependency(provider, virtualPath);
content = LoadContent(file);
HttpRuntime.Cache.Insert(key, content, dependency);
}
return(new HtmlContentResult(content, key));
}
public CachePolicy CreateCachePolicy(HttpContextBase context)
{
return(HtmlServices.GetCachePolicy(context));
}