Add button to switch between source and rendered blob

- Adds a button to switch between the source blob and the rendered blob.
Currently these buttons are only shown for markdown files, it is the only blob
that can be shown rendered and shown source without having to show raw
binary code.
- Resolves go-gitea#11259

Author: Gusted

options/locale/locale_en-US.ini

@@ -1027,6 +1027,8 @@ file_view_source = View Source
 file_view_rendered = View Rendered
 file_view_raw = View Raw
 file_permalink = Permalink
+file_view_source_blob = View Source Blob
+file_view_rendered_blob = View Rendered Blob
 file_too_large = The file is too large to be shown.
 bidi_bad_header = `This file contains unexpected Bidirectional Unicode characters!`
 bidi_bad_description = `This file contains unexpected Bidirectional Unicode characters that may be processed differently from what appears below. If your use case is intentional and legitimate, you can safely ignore this warning. Use the Escape button to reveal hidden characters.`

routers/web/repo/view.go

@@ -489,9 +489,14 @@ func renderFile(ctx *context.Context, entry *git.TreeEntry, treeLink, rawLink st
 		}
 
 		rd := charset.ToUTF8WithFallbackReader(io.MultiReader(bytes.NewReader(buf), dataRc))
-		readmeExist := markup.IsReadmeFile(blob.Name())
+		shouldRenderMarkdown := !ctx.FormBool("plain")
+		readmeExist := markup.IsReadmeFile(blob.Name()) && shouldRenderMarkdown
 		ctx.Data["ReadmeExist"] = readmeExist
-		if markupType := markup.Type(blob.Name()); markupType != "" {
+
+		markupType := markup.Type(blob.Name())
+		ctx.Data["IsMarkdownBlob"] = markupType != ""
+
+		if markupType != "" && shouldRenderMarkdown {
 			ctx.Data["IsMarkup"] = true
 			ctx.Data["MarkupType"] = markupType
 			var result strings.Builder

templates/repo/view_file.tmpl

@@ -39,6 +39,12 @@
 			{{end}}
 			{{if not .ReadmeInList}}
 				<div class="ui buttons mr-2">
+					{{if and .IsMarkdownBlob .IsMarkup}}
+						<a class="ui mini basic button" href="{{.RepoLink}}/src/{{.BranchNameSubURL}}/{{PathEscapeSegments .TreePath}}?plain=1">{{.i18n.Tr "repo.file_view_source_blob"}}</a>
+					{{end}}
+					{{if and .IsMarkdownBlob (not .IsMarkup)}}
+						<a class="ui mini basic button" href="{{.RepoLink}}/src/{{.BranchNameSubURL}}/{{PathEscapeSegments .TreePath}}">{{.i18n.Tr "repo.file_view_rendered_blob"}}</a>
+					{{end}}
 					<a class="ui mini basic button" href="{{$.RawFileLink}}">{{.i18n.Tr "repo.file_raw"}}</a>
 					{{if not .IsViewCommit}}
 						<a class="ui mini basic button" href="{{.RepoLink}}/src/commit/{{PathEscape .CommitID}}/{{PathEscapeSegments .TreePath}}">{{.i18n.Tr "repo.file_permalink"}}</a>