public void OnActionExecuting(ActionExecutingContext filterContext)
{
// use the action in the cacheKey so that the same route can't return cache for different actions
_actionName = filterContext.ActionDescriptor.ActionName;
// apply OutputCacheAttribute logic if defined
var outputCacheAttribute = filterContext.ActionDescriptor.GetCustomAttributes(typeof (OutputCacheAttribute), true).Cast<OutputCacheAttribute>().FirstOrDefault() ;
if(outputCacheAttribute != null) {
if (outputCacheAttribute.Duration <= 0 || outputCacheAttribute.NoStore) {
Logger.Debug("Request ignored based on OutputCache attribute");
return;
}
}
// saving the current datetime
_now = _clock.UtcNow;
// before executing an action, we check if a valid cached result is already
// existing for this context (url, theme, culture, tenant)
Logger.Debug("Request on: " + filterContext.RequestContext.HttpContext.Request.RawUrl);
// don't cache POST requests
if(filterContext.HttpContext.Request.HttpMethod.Equals("POST", StringComparison.OrdinalIgnoreCase) ) {
Logger.Debug("Request ignored on POST");
return;
}
// don't cache the admin
if (AdminFilter.IsApplied(new RequestContext(filterContext.HttpContext, new RouteData()))) {
Logger.Debug("Request ignored on Admin section");
return;
}
// ignore child actions, e.g. HomeController is using RenderAction()
if (filterContext.IsChildAction){
Logger.Debug("Request ignored on Child actions");
return;
}
_workContext = _workContextAccessor.GetContext();
// don't return any cached content, or cache any content, if the user is authenticated
if (_workContext.CurrentUser != null) {
Logger.Debug("Request ignored on Authenticated user");
return;
}
// caches the default cache duration to prevent a query to the settings
_cacheDuration = _cacheManager.Get("CacheSettingsPart.Duration",
context => {
context.Monitor(_signals.When(CacheSettingsPart.CacheKey));
return _workContext.CurrentSite.As<CacheSettingsPart>().DefaultCacheDuration;
}
);
// caches the default max age duration to prevent a query to the settings
_maxAge = _cacheManager.Get("CacheSettingsPart.MaxAge",
context => {
context.Monitor(_signals.When(CacheSettingsPart.CacheKey));
return _workContext.CurrentSite.As<CacheSettingsPart>().DefaultMaxAge;
}
);
// caches the ignored urls to prevent a query to the settings
_ignoredUrls = _cacheManager.Get("CacheSettingsPart.IgnoredUrls",
context => {
context.Monitor(_signals.When(CacheSettingsPart.CacheKey));
return _workContext.CurrentSite.As<CacheSettingsPart>().IgnoredUrls;
}
);
// caches the culture setting
_applyCulture = _cacheManager.Get("CacheSettingsPart.ApplyCulture",
context => {
context.Monitor(_signals.When(CacheSettingsPart.CacheKey));
return _workContext.CurrentSite.As<CacheSettingsPart>().ApplyCulture;
}
);
// caches the ignored urls to prevent a query to the settings
_debugMode = _cacheManager.Get("CacheSettingsPart.DebugMode",
context => {
context.Monitor(_signals.When(CacheSettingsPart.CacheKey));
return _workContext.CurrentSite.As<CacheSettingsPart>().DebugMode;
}
);
CacheItem cacheItem = null;
var queryString = filterContext.RequestContext.HttpContext.Request.QueryString;
var parameters = new Dictionary<string, object>(filterContext.ActionParameters);
foreach(var key in queryString.AllKeys) {
parameters[key] = queryString[key];
}
// compute the cache key
_cacheKey = ComputeCacheKey(filterContext, parameters);
// create a tag which doesn't care about querystring
_invariantCacheKey = ComputeCacheKey(filterContext, null);
// don't retrieve cache content if refused
// in this case the result of the action will update the current cached version
if (filterContext.RequestContext.HttpContext.Request.Headers["Cache-Control"] != "no-cache") {
// fetch cached data
cacheItem = _cacheStorageProvider.GetCacheItem(_cacheKey);
if(cacheItem == null) {
Logger.Debug("Cached version not found");
}
}
else {
Logger.Debug("Cache-Control = no-cache requested");
}
var response = filterContext.HttpContext.Response;
// render cached content
if (cacheItem != null)
{
Logger.Debug("Cache item found, expires on " + cacheItem.ValidUntilUtc);
var output = cacheItem.Output;
/*
*
* There is no need to replace the AntiForgeryToken as it is not used for unauthenticated requests
* and at this point, the request can't be authenticated
*
*
// replace any anti forgery token with a fresh value
if (output.Contains(AntiforgeryBeacon))
{
var viewContext = new ViewContext
{
HttpContext = filterContext.HttpContext,
Controller = filterContext.Controller
};
var htmlHelper = new HtmlHelper(viewContext, new ViewDataContainer());
var siteSalt = _workContext.CurrentSite.SiteSalt;
var token = htmlHelper.AntiForgeryToken(siteSalt);
output = output.Replace(AntiforgeryBeacon, token.ToString());
}
*/
// adds some caching information to the output if requested
if (_debugMode)
{
output += "\r\n<!-- Cached on " + cacheItem.CachedOnUtc + " (UTC) until " + cacheItem.ValidUntilUtc + " (UTC) -->";
response.AddHeader("X-Cached-On", cacheItem.CachedOnUtc.ToString("r"));
response.AddHeader("X-Cached-Until", cacheItem.ValidUntilUtc.ToString("r"));
}
filterContext.Result = new ContentResult
{
Content = output,
ContentType = cacheItem.ContentType
};
response.StatusCode = cacheItem.StatusCode;
ApplyCacheControl(cacheItem, response, output);
return;
}
// no cache content available, intercept the execution results for caching
response.Filter = _filter = new CapturingResponseFilter(response.Filter);
}
public void OnActionExecuted(ActionExecutedContext filterContext)
{
// ignore error results from cache
if (filterContext.HttpContext.Response.StatusCode != (int)HttpStatusCode.OK) {
_filter = null;
return;
}
// if the result of a POST is a Redirect, remove any Cache Item for this url
// so that the redirected client gets a fresh result
// also add a random token to the query string so that public cachers (IIS, proxies, ...) don't return cached content
// i.e., Comment creation
// ignore in admin
if (AdminFilter.IsApplied(new RequestContext(filterContext.HttpContext, new RouteData()))) {
return;
}
_workContext = _workContextAccessor.GetContext();
// ignore authenticated requests
if (_workContext.CurrentUser != null) {
return;
}
if (filterContext.HttpContext.Request.HttpMethod.Equals("POST", StringComparison.OrdinalIgnoreCase)
&& filterContext.Result is RedirectResult) {
Logger.Debug("Redirect on POST");
var redirectUrl = ((RedirectResult)filterContext.Result).Url;
if (!VirtualPathUtility.IsAbsolute(redirectUrl)) {
var applicationRoot = filterContext.HttpContext.Request.ToRootUrlString();
if (redirectUrl.StartsWith(applicationRoot, StringComparison.OrdinalIgnoreCase)) {
redirectUrl = redirectUrl.Substring(applicationRoot.Length);
}
}
// querystring invariant key
var invariantCacheKey = ComputeCacheKey(
_shellSettings.Name,
redirectUrl,
() => _workContext.CurrentCulture,
_themeManager.GetRequestTheme(filterContext.RequestContext).Id,
null
);
_cacheService.RemoveByTag(invariantCacheKey);
// adding a refresh key so that the next request will not be cached
var epIndex = redirectUrl.IndexOf('?');
var qs = new NameValueCollection();
if (epIndex > 0) {
qs = HttpUtility.ParseQueryString(redirectUrl.Substring(epIndex));
}
var refresh = _now.Ticks;
qs.Remove(RefreshKey);
qs.Add(RefreshKey, refresh.ToString("x"));
var querystring = "?" + string.Join("&", Array.ConvertAll(qs.AllKeys, k => string.Format("{0}={1}", HttpUtility.UrlEncode(k), HttpUtility.UrlEncode(qs[k]))));
if (epIndex > 0) {
redirectUrl = redirectUrl.Substring(0, epIndex) + querystring;
}
else {
redirectUrl = redirectUrl + querystring;
}
filterContext.Result = new RedirectResult(redirectUrl, ((RedirectResult)filterContext.Result).Permanent);
filterContext.HttpContext.Response.Cache.SetCacheability(HttpCacheability.NoCache);
}
}
