/// <summary>
/// Writes the specified <paramref name="value"/> with HTML encoding to given <paramref name="content"/>.
/// </summary>
/// <param name="content">The <see cref="TagHelperContent"/> to write to.</param>
/// <param name="encoder">The <see cref="IHtmlEncoder"/> to use when encoding <paramref name="value"/>.</param>
/// <param name="encoding">The character encoding in which the <paramref name="value"/> is written.</param>
/// <param name="value">The <see cref="object"/> to write.</param>
/// <returns><paramref name="content"/> after the write operation has completed.</returns>
/// <remarks>
/// <paramref name="value"/>s of type <see cref="Html.Abstractions.IHtmlContent"/> are written using
/// <see cref="Html.Abstractions.IHtmlContent.WriteTo(System.IO.TextWriter, IHtmlEncoder)"/>.
/// For all other types, the encoded result of <see cref="object.ToString"/>
/// is written to the <paramref name="content"/>.
/// </remarks>
public static TagHelperContent Append(
this TagHelperContent content,
IHtmlEncoder encoder,
Encoding encoding,
object value)
{
if (content == null)
{
throw new ArgumentNullException(nameof(content));
}
if (encoder == null)
{
throw new ArgumentNullException(nameof(encoder));
}
if (encoding == null)
{
throw new ArgumentNullException(nameof(encoding));
}
using (var writer = new TagHelperContentWrapperTextWriter(encoding, content))
{
RazorPage.WriteTo(writer, encoder, value, escapeQuotes: true);
}
return content;
}
/// <summary>
/// Writes the specified <paramref name="value"/> with HTML encoding to given <paramref name="content"/>.
/// </summary>
/// <param name="content">The <see cref="TagHelperContent"/> to write to.</param>
/// <param name="encoder">The <see cref="IHtmlEncoder"/> to use when encoding <paramref name="value"/>.</param>
/// <param name="encoding">The character encoding in which the <paramref name="value"/> is written.</param>
/// <param name="value">The <see cref="object"/> to write.</param>
/// <returns><paramref name="content"/> after the write operation has completed.</returns>
/// <remarks>
/// <paramref name="value"/>s of type <see cref="Rendering.HtmlString"/> are written without encoding and
/// <see cref="HelperResult.WriteTo"/> is invoked for <see cref="HelperResult"/> types. For all other types,
/// the encoded result of <see cref="object.ToString"/> is written to the <paramref name="content"/>.
/// </remarks>
public static TagHelperContent Append(
[NotNull] this TagHelperContent content,
[NotNull] IHtmlEncoder encoder,
[NotNull] Encoding encoding,
object value)
{
using (var writer = new TagHelperContentWrapperTextWriter(encoding, content))
{
RazorPage.WriteTo(writer, encoder, value, escapeQuotes: true);
}
return content;
}
public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
{
output.TagName = null;
var partialResult = _viewEngine.FindPartialView(ViewContext, Name);
if (partialResult != null && partialResult.Success)
{
var partialViewData = new ViewDataDictionary(ViewContext.ViewData, Model);
var partialWriter = new TagHelperContentWrapperTextWriter(ViewContext.Writer.Encoding, output.Content);
var partialViewContext = new ViewContext(ViewContext, partialResult.View, partialViewData, partialWriter);
await partialResult.View.RenderAsync(partialViewContext);
}
}
/// <summary>
/// Ends the current writing scope that was started by calling <see cref="StartTagHelperWritingScope"/>.
/// </summary>
/// <returns>The <see cref="TextWriter"/> that contains the content written to the <see cref="Output"/> or
/// <see cref="ViewContext.Writer"/> during the writing scope.</returns>
public TagHelperContent EndTagHelperWritingScope()
{
if (_writerScopes.Count == 0)
{
throw new InvalidOperationException(Resources.RazorPage_ThereIsNoActiveWritingScopeToEnd);
}
var writer = _writerScopes.Pop();
if (_writerScopes.Count > 0)
{
ViewContext.Writer = _writerScopes.Peek();
}
else
{
ViewContext.Writer = _originalWriter;
// No longer a base writer
_originalWriter = null;
}
var tagHelperContentWrapperTextWriter = new TagHelperContentWrapperTextWriter(Output.Encoding);
var razorWriter = writer as RazorTextWriter;
if (razorWriter != null)
{
razorWriter.CopyTo(tagHelperContentWrapperTextWriter);
}
else
{
var stringCollectionTextWriter = writer as StringCollectionTextWriter;
if (stringCollectionTextWriter != null)
{
stringCollectionTextWriter.CopyTo(tagHelperContentWrapperTextWriter);
}
else
{
tagHelperContentWrapperTextWriter.Write(writer.ToString());
}
}
return(tagHelperContentWrapperTextWriter.Content);
}
