private void HandleBeginRequest(object sender, EventArgs e)
{
var application = (HttpApplication)sender;
var context = application.Context;
var relativeFilePath = context.Request.AppRelativeCurrentExecutionFilePath.TrimStart('~');
// Check whether the current request URL contains information about a preview mode
if (HandleVirtualContext(ref relativeFilePath))
{
// Validate integrity of preview information (including the unique identifier generated by Kentico) in the current request URL
if (!VirtualContext.ValidatePreviewHash(relativeFilePath) || !ValidatePreviewGuid(VirtualContext.GetItem(VirtualContext.PARAM_WF_GUID)))
{
VirtualContext.Reset();
throw new HttpException(404, "The preview link is not valid.");
}
// Disable same origin policy for a preview mode as Kentico displays preview in a frame
AntiForgeryConfig.SuppressXFrameOptionsHeader = true;
// Do not cache response in a preview mode, it has to contain current data
context.Response.Cache.SetNoServerCaching();
context.Response.Cache.SetNoStore();
// Remove preview mode information from the request URL
context.RewritePath("~" + relativeFilePath, context.Request.PathInfo, context.Request.Url.Query.TrimStart('?'));
}
var previewFeature = new PreviewFeature();
context.Kentico().SetFeature <IPreviewFeature>(previewFeature);
}
/// <summary>
/// Handles the virtual context for the request.
/// </summary>
/// <param name="relativePath">Relative path. If loading succeeded, returns updated virtual path without the context values.</param>
/// <returns>True, if loading of the virtual context succeeded and the request is a virtual context request, otherwise false.</returns>
/// <exception cref="HttpException">When virtual context is invalid.</exception>
private static bool HandleVirtualContext(ref string relativePath)
{
try
{
return(VirtualContext.HandleVirtualContext(ref relativePath));
}
catch (InvalidVirtualContextException ex)
{
VirtualContext.Reset();
throw new HttpException(404, "The preview link is not valid.", ex);
}
}