Fix relative link URL in Markdown output (#1189)

assets/js/hooks/markdown_renderer.js

@@ -13,7 +13,9 @@ const MarkdownRenderer = {
   mounted() {
     this.props = this.getProps();
 
-    const markdown = new Markdown(this.el, "");
+    const markdown = new Markdown(this.el, "", {
+      baseUrl: this.props.sessionPath,
+    });
 
     this.handleEvent(
       `markdown_renderer:${this.props.id}:content`,
@@ -26,6 +28,7 @@ const MarkdownRenderer = {
   getProps() {
     return {
       id: getAttributeOrThrow(this.el, "data-id"),
+      sessionPath: getAttributeOrThrow(this.el, "data-session-path"),
     };
   },
 };

lib/livebook_web/live/output.ex

@@ -47,8 +47,12 @@ defmodule LivebookWeb.Output do
     """
   end
 
-  defp render_output({:markdown, markdown}, %{id: id}) do
+  defp render_output({:markdown, markdown}, %{id: id, session_id: session_id}) do
-    live_component(Output.MarkdownComponent, id: id, content: markdown)
+    live_component(Output.MarkdownComponent,
+      id: id,
+      session_id: session_id,
+      content: markdown
+    )
   end
 
   defp render_output({:image, content, mime_type}, %{id: id}) do

lib/livebook_web/live/output/markdown_component.ex

@@ -17,7 +17,8 @@ defmodule LivebookWeb.Output.MarkdownComponent do
     <div class="markdown"
       id={"markdown-renderer-#{@id}"}
       phx-hook="MarkdownRenderer"
-      data-id={@id}>
+      data-id={@id}
+      data-session-path={Routes.session_path(@socket, :page, @session_id)}>
     </div>
     """
   end