Files
blog.terrible.dev/src/TerribleDev.Blog.Web/MarkExtension/ExternalLinkParser.cs
2019-01-22 09:07:40 -05:00

72 lines
2.4 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Threading.Tasks;
using Markdig.Syntax.Inlines;
namespace TerribleDev.Blog.Web.MarkExtension
{
using System;
using System.Collections.Generic;
using System.Linq;
using Markdig;
using Markdig.Renderers;
using Markdig.Renderers.Html;
using Markdig.Renderers.Html.Inlines;
using Markdig.Syntax.Inlines;
namespace TerribleDev.Blog.Web.ExternalLinkParser
{
/// <summary>
/// Extension for extending image Markdown links in case a video or an audio file is linked and output proper link.
/// </summary>
/// <seealso cref="Markdig.IMarkdownExtension" />
public class TargetLinkExtension : IMarkdownExtension
{
public void Setup(MarkdownPipelineBuilder pipeline)
{
}
public void Setup(MarkdownPipeline pipeline, IMarkdownRenderer renderer)
{
var htmlRenderer = renderer as HtmlRenderer;
if (htmlRenderer != null)
{
var inlineRenderer = htmlRenderer.ObjectRenderers.FindExact<LinkInlineRenderer>();
if (inlineRenderer != null)
{
inlineRenderer.TryWriters.Remove(TryLinkInlineRenderer);
inlineRenderer.TryWriters.Add(TryLinkInlineRenderer);
}
}
}
private bool TryLinkInlineRenderer(HtmlRenderer renderer, LinkInline linkInline)
{
if (linkInline.Url == null)
{
return false;
}
Uri uri;
// Only process absolute Uri
if (!Uri.TryCreate(linkInline.Url, UriKind.RelativeOrAbsolute, out uri) || !uri.IsAbsoluteUri)
{
return false;
}
RenderTargetAttribute(uri, renderer, linkInline);
return false;
}
private void RenderTargetAttribute(Uri uri, HtmlRenderer renderer, LinkInline linkInline)
{
linkInline.SetAttributes(new HtmlAttributes() { Properties = new List<KeyValuePair<string, string>>() { new KeyValuePair<string, string>("target", "_blank"), new KeyValuePair<string, string>("rel", "noopener"), } });
}
}
}
}