private async Task RenderLayoutAsync(ViewContext context,
RazorTextWriter bodyWriter)
{
// A layout page can specify another layout page. We'll need to continue
// looking for layout pages until they're no longer specified.
var previousPage = _page;
while (!string.IsNullOrEmpty(previousPage.Layout))
{
var layoutPage = _pageFactory.CreateInstance(previousPage.Layout);
if (layoutPage == null)
{
var message = Resources.FormatLayoutCannotBeLocated(previousPage.Layout);
throw new InvalidOperationException(message);
}
layoutPage.PreviousSectionWriters = previousPage.SectionWriters;
layoutPage.RenderBodyDelegate = bodyWriter.CopyTo;
bodyWriter = await RenderPageAsync(layoutPage, context, executeViewStart : false);
// Verify that RenderBody is called, or that RenderSection is called for all sections
layoutPage.EnsureBodyAndSectionsWereRendered();
previousPage = layoutPage;
}
await bodyWriter.CopyToAsync(context.Writer);
}
private async Task RenderLayoutAsync(ViewContext context,
RazorTextWriter bodyWriter)
{
// A layout page can specify another layout page. We'll need to continue
// looking for layout pages until they're no longer specified.
var previousPage = _razorPage;
while (!string.IsNullOrEmpty(previousPage.Layout))
{
if (!bodyWriter.IsBuffering)
{
// Once a call to RazorPage.FlushAsync is made, we can no longer render Layout pages - content has
// already been written to the client and the layout content would be appended rather than surround
// the body content. Throwing this exception wouldn't return a 500 (since content has already been
// written), but a diagnostic component should be able to capture it.
var message = Resources.FormatLayoutCannotBeRendered("FlushAsync");
throw new InvalidOperationException(message);
}
var layoutPage = _pageFactory.CreateInstance(previousPage.Layout);
if (layoutPage == null)
{
var message = Resources.FormatLayoutCannotBeLocated(previousPage.Layout);
throw new InvalidOperationException(message);
}
// Notify the previous page that any writes that are performed on it are part of sections being written
// in the layout.
previousPage.IsLayoutBeingRendered = true;
layoutPage.PreviousSectionWriters = previousPage.SectionWriters;
layoutPage.RenderBodyDelegate = bodyWriter.CopyTo;
bodyWriter = await RenderPageAsync(layoutPage, context, executeViewStart : false);
// Verify that RenderBody is called, or that RenderSection is called for all sections
layoutPage.EnsureBodyAndSectionsWereRendered();
previousPage = layoutPage;
}
if (bodyWriter.IsBuffering)
{
// Only copy buffered content to the Output if we're currently buffering.
await bodyWriter.CopyToAsync(context.Writer);
}
}
private async Task RenderLayoutAsync(ViewContext context,
RazorTextWriter bodyWriter)
{
// A layout page can specify another layout page. We'll need to continue
// looking for layout pages until they're no longer specified.
var previousPage = _page;
while (!string.IsNullOrEmpty(previousPage.Layout))
{
var layoutPage = _pageFactory.CreateInstance(previousPage.Layout);
if (layoutPage == null)
{
var message = Resources.FormatLayoutCannotBeLocated(previousPage.Layout);
throw new InvalidOperationException(message);
}
layoutPage.PreviousSectionWriters = previousPage.SectionWriters;
layoutPage.RenderBodyDelegate = bodyWriter.CopyTo;
bodyWriter = await RenderPageAsync(layoutPage, context, executeViewStart: false);
// Verify that RenderBody is called, or that RenderSection is called for all sections
layoutPage.EnsureBodyAndSectionsWereRendered();
previousPage = layoutPage;
}
await bodyWriter.CopyToAsync(context.Writer);
}
