Rendering multiple Razor pages to Html - asp.net-core

Question

I have an application that uses Markdown in Razor Pages (compiled using a custom TagHelper) to display static content. There are about 300 pages worth.
I'm trying to render these Razor pages to html so that I can index the content using Lucene.net, in order to provide full text search.
I've managed to create some code (see below) that works, but prepends previously rendered content whenever subsequent pages are rendered. That is, when I render the first page it works perfectly but, when I render another page the first page's content is also included and, when I render a third page the first two pages content are included.
I have tried creating the dependencies manually within the method, and I have tried creating a new instance of this class for each page, but always with the same result.
What am I missing?
public class RazorPageRenderer
{
private readonly IRazorViewEngine razorViewEngine;
private readonly ITempDataProvider tempDataProvider;
private readonly IHttpContextAccessor httpContextAccessor;
private readonly IActionContextAccessor actionContextAccessor;
private readonly IRazorPageActivator razorPageActivator;
private readonly ILogger logger;
public RazorPageRenderer(
IRazorViewEngine razorViewEngine,
ITempDataProvider tempDataProvider,
IHttpContextAccessor httpContextAccessor,
IActionContextAccessor actionContextAccessor,
IRazorPageActivator razorPageActivator,
ILogger<RazorPageRenderer> logger)
{
this.razorViewEngine = razorViewEngine;
this.tempDataProvider = tempDataProvider;
this.httpContextAccessor = httpContextAccessor;
this.actionContextAccessor = actionContextAccessor;
this.razorPageActivator = razorPageActivator;
this.logger = logger;
}
public async Task<string> RenderAsync(IRazorPage razorPage) => await RenderAsync<object>(razorPage, null);
public async Task<string> RenderAsync<T>(IRazorPage razorPage, T model)
{
try
{
var viewDataDictionary = CreateViewDataDictionary(razorPage.GetType(), model);
await using var writer = new StringWriter();
var view = new RazorView(
razorViewEngine,
razorPageActivator,
Array.Empty<IRazorPage>(),
razorPage,
HtmlEncoder.Default,
new DiagnosticListener(nameof(RazorPageRenderer)));
var viewContext = new ViewContext(
actionContextAccessor.ActionContext,
view,
viewDataDictionary,
new TempDataDictionary(
httpContextAccessor.HttpContext,
tempDataProvider),
writer,
new HtmlHelperOptions());
if (razorPage is Page page)
{
page.PageContext = new PageContext(actionContextAccessor.ActionContext)
{
ViewData = viewContext.ViewData
};
}
razorPage.ViewContext = viewContext;
razorPageActivator.Activate(razorPage, viewContext);
await razorPage.ExecuteAsync();
return writer.ToString();
}
catch (Exception exception)
{
logger.LogError(
"An exception occured while rendering page: {Page}. Exception: {Exception}",
razorPage.Path,
exception);
}
return null;
}
private static ViewDataDictionary CreateViewDataDictionary(Type pageType, object model)
{
var dictionaryType = typeof(ViewDataDictionary<>)
.MakeGenericType(pageType);
var ctor = dictionaryType.GetConstructor(new[]
{typeof(IModelMetadataProvider), typeof(ModelStateDictionary)});
var viewDataDictionary = (ViewDataDictionary)ctor?.Invoke(
new object[] {new EmptyModelMetadataProvider(), new ModelStateDictionary()});
if (model != null && viewDataDictionary != null)
{
viewDataDictionary.Model = model;
}
return viewDataDictionary;
}
}