/// <summary>
/// Executes a view asynchronously.
/// </summary>
/// <param name="viewContext">The <see cref="ViewContext"/> associated with the current request.</param>
/// <param name="contentType">
/// The content-type header value to set in the response. If <c>null</c>,
/// <see cref="DefaultContentType"/> will be used.
/// </param>
/// <param name="statusCode">
/// The HTTP status code to set in the response. May be <c>null</c>.
/// </param>
/// <returns>A <see cref="Task"/> which will complete when view execution is completed.</returns>
protected async Task ExecuteAsync(
ViewContext viewContext,
string contentType,
int?statusCode)
{
if (viewContext == null)
{
throw new ArgumentNullException(nameof(viewContext));
}
var response = viewContext.HttpContext.Response;
string resolvedContentType;
Encoding resolvedContentTypeEncoding;
ResponseContentTypeHelper.ResolveContentTypeAndEncoding(
contentType,
response.ContentType,
DefaultContentType,
out resolvedContentType,
out resolvedContentTypeEncoding);
response.ContentType = resolvedContentType;
if (statusCode != null)
{
response.StatusCode = statusCode.Value;
}
using (var writer = WriterFactory.CreateWriter(response.Body, resolvedContentTypeEncoding))
{
var view = viewContext.View;
var oldWriter = viewContext.Writer;
try
{
viewContext.Writer = writer;
DiagnosticSource.BeforeView(view, viewContext);
await view.RenderAsync(viewContext);
DiagnosticSource.AfterView(view, viewContext);
}
finally
{
viewContext.Writer = oldWriter;
}
// Perf: Invoke FlushAsync to ensure any buffered content is asynchronously written to the underlying
// response asynchronously. In the absence of this line, the buffer gets synchronously written to the
// response as part of the Dispose which has a perf impact.
await writer.FlushAsync();
}
}
/// <summary>
/// Executes a view asynchronously.
/// </summary>
/// <param name="actionContext">The <see cref="ActionContext"/> associated with the current request.</param>
/// <param name="view">The <see cref="IView"/>.</param>
/// <param name="viewData">The <see cref="ViewDataDictionary"/>.</param>
/// <param name="tempData">The <see cref="ITempDataDictionary"/>.</param>
/// <param name="contentType">
/// The content-type header value to set in the response. If <c>null</c>, <see cref="DefaultContentType"/> will be used.
/// </param>
/// <param name="statusCode">
/// The HTTP status code to set in the response. May be <c>null</c>.
/// </param>
/// <returns>A <see cref="Task"/> which will complete when view execution is completed.</returns>
public virtual async Task ExecuteAsync(
ActionContext actionContext,
IView view,
ViewDataDictionary viewData,
ITempDataDictionary tempData,
MediaTypeHeaderValue contentType,
int?statusCode)
{
if (actionContext == null)
{
throw new ArgumentNullException(nameof(actionContext));
}
if (view == null)
{
throw new ArgumentNullException(nameof(view));
}
var services = actionContext.HttpContext.RequestServices;
if (viewData == null)
{
var metadataProvider = services.GetRequiredService <IModelMetadataProvider>();
viewData = new ViewDataDictionary(metadataProvider);
}
if (tempData == null)
{
tempData = services.GetRequiredService <ITempDataDictionary>();
}
var response = actionContext.HttpContext.Response;
if (contentType != null && contentType.Encoding == null)
{
// Do not modify the user supplied content type, so copy it instead
contentType = contentType.Copy();
contentType.Encoding = Encoding.UTF8;
}
// Priority list for setting content-type:
// 1. passed in contentType (likely set by the user on the result)
// 2. response.ContentType (likely set by the user in controller code)
// 3. ViewExecutor.DefaultContentType (sensible default)
response.ContentType = contentType?.ToString() ?? response.ContentType ?? DefaultContentType.ToString();
if (statusCode != null)
{
response.StatusCode = statusCode.Value;
}
var encoding = contentType?.Encoding ?? DefaultContentType.Encoding;
using (var writer = WriterFactory.CreateWriter(response.Body, encoding))
{
var viewContext = new ViewContext(
actionContext,
view,
viewData,
tempData,
writer,
ViewOptions.HtmlHelperOptions);
DiagnosticSource.BeforeView(view, viewContext);
await view.RenderAsync(viewContext);
DiagnosticSource.AfterView(view, viewContext);
// Perf: Invoke FlushAsync to ensure any buffered content is asynchronously written to the underlying
// response asynchronously. In the absence of this line, the buffer gets synchronously written to the
// response as part of the Dispose which has a perf impact.
await writer.FlushAsync();
}
}
/// <summary>
/// Executes a view asynchronously.
/// </summary>
/// <param name="actionContext">The <see cref="ActionContext"/> associated with the current request.</param>
/// <param name="view">The <see cref="IView"/>.</param>
/// <param name="viewData">The <see cref="ViewDataDictionary"/>.</param>
/// <param name="tempData">The <see cref="ITempDataDictionary"/>.</param>
/// <param name="contentType">
/// The content-type header value to set in the response. If <c>null</c>,
/// <see cref="DefaultContentType"/> will be used.
/// </param>
/// <param name="statusCode">
/// The HTTP status code to set in the response. May be <c>null</c>.
/// </param>
/// <returns>A <see cref="Task"/> which will complete when view execution is completed.</returns>
public virtual async Task ExecuteAsync(
ActionContext actionContext,
IView view,
ViewDataDictionary viewData,
ITempDataDictionary tempData,
string contentType,
int?statusCode)
{
if (actionContext == null)
{
throw new ArgumentNullException(nameof(actionContext));
}
if (view == null)
{
throw new ArgumentNullException(nameof(view));
}
if (viewData == null)
{
viewData = new ViewDataDictionary(_modelMetadataProvider, actionContext.ModelState);
}
if (tempData == null)
{
tempData = TempDataFactory.GetTempData(actionContext.HttpContext);
}
var response = actionContext.HttpContext.Response;
string resolvedContentType = null;
Encoding resolvedContentTypeEncoding = null;
ResponseContentTypeHelper.ResolveContentTypeAndEncoding(
contentType,
response.ContentType,
DefaultContentType,
out resolvedContentType,
out resolvedContentTypeEncoding);
response.ContentType = resolvedContentType;
if (statusCode != null)
{
response.StatusCode = statusCode.Value;
}
using (var writer = WriterFactory.CreateWriter(response.Body, resolvedContentTypeEncoding))
{
var viewContext = new ViewContext(
actionContext,
view,
viewData,
tempData,
writer,
ViewOptions.HtmlHelperOptions);
DiagnosticSource.BeforeView(view, viewContext);
await view.RenderAsync(viewContext);
DiagnosticSource.AfterView(view, viewContext);
// Perf: Invoke FlushAsync to ensure any buffered content is asynchronously written to the underlying
// response asynchronously. In the absence of this line, the buffer gets synchronously written to the
// response as part of the Dispose which has a perf impact.
await writer.FlushAsync();
}
}
