feat: HTML file preview — render .html as pages, not source (Phase 1.1)

Co-authored-by: Cursor <cursoragent@cursor.com>

routers/web/repo/view_file.go

@@ -153,6 +153,19 @@ func handleFileViewRenderImage(ctx *context.Context, fInfo *fileInfo, prefetchBu
 	return true
 }
 
+func handleFileViewRenderHTML(ctx *context.Context, fInfo *fileInfo) bool {
+	if !strings.HasSuffix(strings.ToLower(ctx.Repo.TreePath), ".html") {
+		return false
+	}
+	// Allow toggling to source view
+	if ctx.FormString("display") == "source" {
+		return false
+	}
+	ctx.Data["IsHTMLFile"] = true
+	ctx.Data["HasSourceRenderedToggle"] = true
+	return true
+}
+
 func prepareFileView(ctx *context.Context, entry *git.TreeEntry) {
 	ctx.Data["IsViewFile"] = true
 	ctx.Data["HideRepoInfo"] = true
@@ -239,6 +252,7 @@ func prepareFileView(ctx *context.Context, entry *git.TreeEntry) {
 	case fInfo.blobOrLfsSize >= setting.UI.MaxDisplayFileSize:
 		ctx.Data["IsFileTooLarge"] = true
 	case handleFileViewRenderMarkup(ctx, buf, contentReader):
+	case handleFileViewRenderHTML(ctx, fInfo):
 	case handleFileViewRenderSource(ctx, attrs, fInfo, contentReader):
 		// it also sets ctx.Data["FileContent"] and more
 		ctx.Data["IsDisplayingSource"] = true

templates/repo/view_file.tmpl

@@ -125,11 +125,13 @@
 						<video controls src="{{$.RawFileLink}}">
 							<strong>{{ctx.Locale.Tr "repo.video_not_supported_in_browser"}}</strong>
 						</video>
-					{{else if .IsAudioFile}}
-						<audio controls src="{{$.RawFileLink}}">
-							<strong>{{ctx.Locale.Tr "repo.audio_not_supported_in_browser"}}</strong>
-						</audio>
-					{{else}}
+				{{else if .IsAudioFile}}
+					<audio controls src="{{$.RawFileLink}}">
+						<strong>{{ctx.Locale.Tr "repo.audio_not_supported_in_browser"}}</strong>
+					</audio>
+				{{else if .IsHTMLFile}}
+					<iframe src="{{$.RawFileLink}}" class="html-preview-iframe" style="width:100%;min-height:600px;border:none;" sandbox="allow-scripts allow-same-origin"></iframe>
+				{{else}}
 						<div class="file-view-render-container">
 							<div class="file-view-raw-prompt tw-p-4">
 								<a href="{{$.RawFileLink}}" rel="nofollow">{{ctx.Locale.Tr "repo.file_view_raw"}}</a>