Add SVG rendering in reaction detail tab

app.py

@@ -326,27 +326,26 @@ def _build_dataset_plot(detail: ReactionDetail) -> go.Figure | None:
     return fig
 
 
-def render_reaction_svg(reaction_text: str):
-    reaction_text = (reaction_text or "").strip()
-    if not reaction_text:
-        return gr.update(value=""), "⚠️ Enter a reaction SMILES/SMARTS string (e.g. CH4.O>>CO2)."
-    if ">>" not in reaction_text:
-        return gr.update(value=""), "⚠️ Reaction input must include '>>' separating reactants and products."
+def _render_smiles_to_svg(smiles_text: str) -> str | None:
+    """Helper to render a SMILES/SMARTS reaction string to SVG."""
+    smiles_text = (smiles_text or "").strip()
+    if not smiles_text or ">>" not in smiles_text:
+        return None
 
     try:
-        reaction = rdChemReactions.ReactionFromSmarts(reaction_text, useSmiles=True)
-    except Exception as exc:  # pragma: no cover - RDKit parsing issues
-        return gr.update(value=""), f"🚨 Could not parse reaction: {exc}"
+        reaction = rdChemReactions.ReactionFromSmarts(smiles_text, useSmiles=True)
+    except Exception:
+        return None
 
     if reaction is None or (reaction.GetNumReactantTemplates() == 0 and reaction.GetNumProductTemplates() == 0):
-        return gr.update(value=""), "⚠️ RDKit returned an empty reaction."
+        return None
 
     try:
         svg = Draw.ReactionToImage(reaction, subImgSize=(220, 220), useSVG=True)
-    except Exception as exc:  # pragma: no cover - RDKit drawing issues
-        return gr.update(value=""), f"🚨 Failed to render reaction: {exc}"
+    except Exception:
+        return None
 
-    if isinstance(svg, tuple):  # Some RDKit versions return (svg, legend)
+    if isinstance(svg, tuple):
         svg = svg[0]
     if hasattr(svg, "data"):
         svg = svg.data
@@ -354,33 +353,59 @@ def render_reaction_svg(reaction_text: str):
         svg = svg.decode("utf-8", errors="ignore")
 
     if not isinstance(svg, str) or "<svg" not in svg:
-        svg = f"<pre>{svg}</pre>"
+        return None
 
-    status = (
-        f"Rendered reaction with {reaction.GetNumReactantTemplates()} reactant templates "
-        f"and {reaction.GetNumProductTemplates()} product templates."
-    )
+    return svg
+
+
+def render_reaction_svg(reaction_text: str):
+    reaction_text = (reaction_text or "").strip()
+    if not reaction_text:
+        return "", "⚠️ Enter a reaction SMILES/SMARTS string (e.g. CH4.O>>CO2)."
+    if ">>" not in reaction_text:
+        return "", "⚠️ Reaction input must include '>>' separating reactants and products."
+
+    svg = _render_smiles_to_svg(reaction_text)
+    if not svg:
+        return "", "🚨 Could not parse or render the reaction."
+
+    status = "✅ Reaction rendered successfully."
     return svg, status
 
 
 def fetch_detail(selected_url: str, manual_url: str):
     detail_url = (manual_url or "").strip() or (selected_url or "").strip()
     if not detail_url:
-        return "ℹ️ Select a reaction above or paste a detail URL.", [], None
+        return "ℹ️ Select a reaction above or paste a detail URL.", [], None, ""
 
     try:
         detail = client.fetch_reaction_detail(detail_url)
     except Exception as exc:  # pragma: no cover - network/parsing issues
-        return f"🚨 Could not load detail: {exc}", [], None
+        return f"🚨 Could not load detail: {exc}", [], None, ""
 
     markdown = _format_detail_markdown(detail, detail_url)
     table = _datasets_to_table(detail)
     if not table:
         markdown += "\n\n_No kinetics datasets were returned for this reaction._"
-        return markdown, table, None
+        return markdown, table, None, ""
 
     plot_fig = _build_dataset_plot(detail)
-    return markdown, table, plot_fig
+    
+    # Try to render the reaction title as SVG
+    reaction_svg = ""
+    if detail.title:
+        # Extract SMILES-like patterns from title (heuristic)
+        title = detail.title.strip()
+        # Look for patterns like "A + B → C" or "A >> B"
+        if " → " in title:
+            parts = title.split(" → ")
+            if len(parts) == 2:
+                smiles_attempt = parts[0].replace(" + ", ".") + ">>" + parts[1].replace(" + ", ".")
+                svg = _render_smiles_to_svg(smiles_attempt)
+                if svg:
+                    reaction_svg = svg
+    
+    return markdown, table, plot_fig, reaction_svg
 
 
 def _parse_points(text: str) -> Tuple[List[float], List[float], List[str]]:
@@ -542,6 +567,7 @@ def build_interface() -> gr.Blocks:
                 wrap=True,
             )
             reaction_plot = gr.Plot()
+            reaction_svg = gr.HTML()
 
         search_button.click(
             fn=perform_search,
@@ -552,7 +578,7 @@ def build_interface() -> gr.Blocks:
         detail_button.click(
             fn=fetch_detail,
             inputs=[selection, manual_url],
-            outputs=[detail_markdown, dataset_table, reaction_plot],
+            outputs=[detail_markdown, dataset_table, reaction_plot, reaction_svg],
         )
 
         with gr.Tab("Reaction SVG"):