add check for empty input and show info/error

app.py

@@ -1,3 +1,4 @@
+import base64
 from collections import Counter
 
 import graphviz
@@ -18,83 +19,94 @@ with st.form("input data"):
     src_lang = lang_col.selectbox(label="Language", options=list(LANGUAGES.keys()), index=0)
     submitted = st.form_submit_button("Submit")
 
+error_ct = st.empty()
 if submitted:
-    multilingual = src_lang != "English"
-    model, tokenizer, logitsprocessor = get_resources(multilingual)
-    gen_kwargs = {
-        "max_length": model.config.max_length,
-        "num_beams": model.config.num_beams,
-        "logits_processor": LogitsProcessorList([logitsprocessor])
-    }
-
-    linearized = translate(text, src_lang, model, tokenizer, **gen_kwargs)
-    penman_str = linearized2penmanstr(linearized)
-
-    try:
-        graph = penman.decode(penman_str, model=NoOpModel())
-    except Exception as exc:
-        st.write(f"The generated graph is not valid so it cannot be visualized correctly. Below is the closest attempt"
-                 f" to a valid graph but note that this is invalid Penman.")
-        st.code(penman_str)
-
-        with st.expander("Error trace"):
-            st.write(exc)
+    text = text.strip()
+    if not text:
+        error_ct.error("Text cannot be empty!", icon="⚠️")
     else:
-        visualized = graphviz.Digraph(node_attr={"color": "#3aafa9", "style": "rounded,filled", "shape": "box",
-                                                 "fontcolor": "white"})
-
-        # Count which names occur multiple times, e.g. t/talk-01 t2/talk-01
-        nodename_c = Counter([item[2] for item in graph.triples if item[1] == ":instance"])
-        # Generated initial nodenames for each variable, e.g. {"t": "talk-01",  "t2": "talk-01"}
-        nodenames = {item[0]: item[2] for item in graph.triples if item[1] == ":instance"}
-
-        # Modify nodenames, so that the values are unique, e.g. {"t": "talk-01 (1)",  "t2": "talk-01 (2)"}
-        # but only the value occurs more than once
-        nodename_str_c = Counter()
-        for varname in nodenames:
-            nodename = nodenames[varname]
-            if nodename_c[nodename] > 1:
-                nodename_str_c[nodename] += 1
-                nodenames[varname] = f"{nodename} ({nodename_str_c[nodename]})"
-
-        def get_node_name(item: str):
-            return nodenames[item] if item in nodenames else item
+        error_ct.info("Generating abstract meaning representation (AMR)...", icon="💻")
+        multilingual = src_lang != "English"
+        model, tokenizer, logitsprocessor = get_resources(multilingual)
+        gen_kwargs = {
+            "max_length": model.config.max_length,
+            "num_beams": model.config.num_beams,
+            "logits_processor": LogitsProcessorList([logitsprocessor])
+        }
+
+        linearized = translate(text, src_lang, model, tokenizer, **gen_kwargs)
+        penman_str = linearized2penmanstr(linearized)
+        error_ct.empty()
 
         try:
-            for triple in graph.triples:
-                if triple[1] == ":instance":
-                    continue
-                else:
-                    visualized.edge(get_node_name(triple[0]), get_node_name(triple[2]), label=triple[1])
+            graph = penman.decode(penman_str, model=NoOpModel())
         except Exception as exc:
-            st.write("The generated graph is not valid so it cannot be visualized correctly. Below is the closest attempt"
-                     " to a valid graph but note that this is probably invalid Penman.")
+            st.write(f"The generated graph is not valid so it cannot be visualized correctly. Below is the closest attempt"
+                     f" to a valid graph but note that this is invalid Penman.")
             st.code(penman_str)
-            st.write("The initial linearized output of the model was:")
-            st.code(linearized)
 
             with st.expander("Error trace"):
                 st.write(exc)
         else:
-            st.subheader("Graph visualization")
-            st.graphviz_chart(visualized, use_container_width=True)
-
-            # Download
-            img = visualized.pipe(format="png")
-            st.download_button("Download graph", img, mime="image/png")
-
-            # Additional info
-            st.subheader("Model output and Penman graph")
-            st.write("The linearized output of the model (after some post-processing) is:")
-            st.code(linearized)
-            st.write("When converted into Penman, it looks like this:")
-            st.code(penman.encode(graph))
+            visualized = graphviz.Digraph(node_attr={"color": "#3aafa9", "style": "rounded,filled", "shape": "box",
+                                                     "fontcolor": "white"})
+
+            # Count which names occur multiple times, e.g. t/talk-01 t2/talk-01
+            nodename_c = Counter([item[2] for item in graph.triples if item[1] == ":instance"])
+            # Generated initial nodenames for each variable, e.g. {"t": "talk-01",  "t2": "talk-01"}
+            nodenames = {item[0]: item[2] for item in graph.triples if item[1] == ":instance"}
+
+            # Modify nodenames, so that the values are unique, e.g. {"t": "talk-01 (1)",  "t2": "talk-01 (2)"}
+            # but only the value occurs more than once
+            nodename_str_c = Counter()
+            for varname in nodenames:
+                nodename = nodenames[varname]
+                if nodename_c[nodename] > 1:
+                    nodename_str_c[nodename] += 1
+                    nodenames[varname] = f"{nodename} ({nodename_str_c[nodename]})"
+
+            def get_node_name(item: str):
+                return nodenames[item] if item in nodenames else item
+
+            try:
+                for triple in graph.triples:
+                    if triple[1] == ":instance":
+                        continue
+                    else:
+                        visualized.edge(get_node_name(triple[0]), get_node_name(triple[2]), label=triple[1])
+            except Exception as exc:
+                st.write("The generated graph is not valid so it cannot be visualized correctly. Below is the closest attempt"
+                         " to a valid graph but note that this is probably invalid Penman.")
+                st.code(penman_str)
+                st.write("The initial linearized output of the model was:")
+                st.code(linearized)
+
+                with st.expander("Error trace"):
+                    st.write(exc)
+            else:
+                st.subheader("Graph visualization")
+                st.graphviz_chart(visualized, use_container_width=True)
+
+                # Download link
+                def create_download_link(img_bytes: bytes):
+                    encoded = base64.b64encode(img_bytes).decode("utf-8")
+                    return f'<a href="data:image/png;charset=utf-8;base64,{encoded}" download="amr-graph.png">Download graph</a>'
+
+                img = visualized.pipe(format="png")
+                st.markdown(create_download_link(img), unsafe_allow_html=True)
+
+                # Additional info
+                st.subheader("Model output and Penman graph")
+                st.write("The linearized output of the model (after some post-processing) is:")
+                st.code(linearized)
+                st.write("When converted into Penman, it looks like this:")
+                st.code(penman.encode(graph))
 
 
 ########################
 # Information, socials #
 ########################
-st.markdown("## Project: SignON 🤟")
+st.header("Project: SignON 🤟")
 
 st.markdown("""
 <div style="display: flex">
@@ -108,7 +120,7 @@ st.markdown("""
 """, unsafe_allow_html=True)
 
 
-st.markdown("## Contact ✒️")
+st.header("Contact ✒️")
 
 st.markdown("Would you like  additional functionality in the demo? Or just want to get in touch?"
             " Give me a shout on [Twitter](https://twitter.com/BramVanroy)"