Merge pull request #347 from crupest/markdown

Markdown post auto translate data url.

1 files changed, 52 insertions, 0 deletions

diff --git a/BackEnd/Timeline/Services/MarkdownProcessor.cs b/BackEnd/Timeline/Services/MarkdownProcessor.cs
new file mode 100644
index 00000000..f34432cd
--- /dev/null
+++ b/BackEnd/Timeline/Services/MarkdownProcessor.cs
@@ -0,0 +1,52 @@
+using System;

+using System.IO;

+using System.Linq;

+using System.Text;

+using Markdig;

+using Markdig.Renderers.Normalize;

+using Markdig.Syntax;

+using Markdig.Syntax.Inlines;

+using Microsoft.AspNetCore.Mvc;

+using Timeline.Controllers;

+

+namespace Timeline.Services

+{

+    public class MarkdownProcessor

+    {

+        public string Process(string text, Func<long, string> urlGenerator)

+        {

+            MarkdownDocument markdown = Markdown.Parse(text);

+            foreach (var link in markdown.Descendants().Where(e => e is LinkInline).Cast<LinkInline>())

+            {

+                if (int.TryParse(link.Url, out var dataIndex))

+                {

+                    link.Url = urlGenerator(dataIndex);

+                }

+            }

+

+            var writer = new StringWriter();

+            NormalizeRenderer renderer = new NormalizeRenderer(writer);

+            renderer.Render(markdown);

+

+            return writer.ToString();

+        }

+

+        /// <summary>Convert data url to true url with post id.</summary>

+        public string Process(string text, IUrlHelper url, string timeline, long post)

+        {

+            return Process(

+                text,

+                dataIndex => url.ActionLink(

+                    nameof(TimelinePostController.DataGet),

+                    nameof(TimelinePostController)[0..^nameof(Controller).Length],

+                    new { timeline, post, data_index = dataIndex }

+                )

+            );

+        }

+

+        public byte[] Process(byte[] data, IUrlHelper url, string timeline, long post)

+        {

+            return Encoding.UTF8.GetBytes(Process(Encoding.UTF8.GetString(data), url, timeline, post));

+        }

+    }

+}