fix links + prevent duplication

app.py

@@ -98,6 +98,14 @@ def submit_entry(
         errors.append("Approximate size must be a non-negative number.")
     if not field.strip():
         errors.append("Please provide a field.")
+    
+    # Check for existing dataset URL and name
+    existing_records = read_all_records()
+    for record in existing_records:
+        if record.get("dataset_url", "").strip().lower() == dataset_url.strip().lower():
+            errors.append(f"Dataset URL already exists: {record.get('dataset_url')}")
+        if record.get("dataset_name", "").strip().lower() == dataset_name.strip().lower():
+            errors.append(f"Dataset name already exists: {record.get('dataset_name')}")
 
     if errors:
         return gr.update(value=f"Submission failed:\n- " + "\n- ".join(errors), visible=True), gr.update(visible=False)
@@ -121,7 +129,7 @@ def submit_entry(
     ok = f"Thanks, {user_display}. Your entry has been saved locally and will sync to the Hub within ~{COMMIT_EVERY_MIN} minutes."
     updated = read_all_records()
     rows = [
-        [r["dataset_name"], r["dataset_url"], r["description"], f"{r['approx_size']} {r['size_unit']}", r["field"], r["user"], r["created_at"]]
+        [r["dataset_name"], f'<a href="{r["dataset_url"]}" target="_blank">{r["dataset_url"]}</a>', r["description"], f"{r['approx_size']} {r['size_unit']}", r["field"], r["user"], r["created_at"]]
         for r in updated
     ]
     return gr.update(value=ok, visible=True), rows
@@ -131,7 +139,7 @@ def refresh_table(field: str, search: str):
     data = read_all_records()
     data = filter_records(data, field, search)
     rows = [
-        [r["dataset_name"], r["dataset_url"], r["description"], f"{r['approx_size']} {r['size_unit']}", r["field"], r["user"], r["created_at"]]
+        [r["dataset_name"], f'<a href="{r["dataset_url"]}" target="_blank">{r["dataset_url"]}</a>', r["description"], f"{r['approx_size']} {r['size_unit']}", r["field"], r["user"], r["created_at"]]
         for r in data
     ]
     return rows
@@ -164,7 +172,7 @@ with gr.Blocks(title="Community Dataset Index", css=".wrap {max-width: 1200px; m
                 refresh = gr.Button("Refresh")
             table = gr.Dataframe(
                 headers=["Name", "URL", "Description", "Size", "Field", "User", "Created"],
-                datatype=["str", "str", "str", "str", "str", "str", "str"],
+                datatype=["str", "html", "str", "str", "str", "str", "str"],
                 interactive=False,
                 wrap=True,
             )