add: Display rendered System and User prompts

README.md

@@ -124,6 +124,9 @@ using **comma** as the separator, and enclosing values (where needed) in **doubl
 ### Using input data in prompts
 
 The user/system prompt textboxes support [Jinja](https://jinja.palletsprojects.com/) templates. 
+Don't worry if you're new to Jinja -- Prompterator can show you a real-time "compiled" preview of 
+your prompts to help you write the templates.
+
 Given a column named `text` in your uploaded CSV data, you can include values from this column by 
 writing the simple `{{text}}` template in your prompt.
 

prompterator/constants.py

@@ -112,5 +112,6 @@ def call(self, input, **kwargs):
 DEFAULT_ROW_NO = 0
 DATA_POINT_TEXT_AREA_HEIGHT = 180
 PROMPT_TEXT_AREA_HEIGHT = 300
+PROMPT_PREVIEW_TEXT_AREA_HEIGHT = 200
 
 DATAFILE_FILTER_ALL = "all"

prompterator/main.py

@@ -68,6 +68,7 @@ def initialise_session_from_uploaded_file(df):
 
     st.session_state["df"] = df
     st.session_state[c.COLS_TO_SHOW_KEY] = [c.TEXT_ORIG_COL]
+    st.session_state.row = st.session_state.df.iloc[c.DEFAULT_ROW_NO]
 
     if st.session_state.responses_generated_externally:
         st.session_state.enable_labelling = True
@@ -432,17 +433,36 @@ def set_up_ui_generation():
         height=c.PROMPT_TEXT_AREA_HEIGHT,
         disabled=not model_supports_user_prompt,
     )
-    col1, col2 = st.columns([1, 2])
+
     if "df" in st.session_state:
-        cols_for_interpolation = set(st.session_state.df.columns).difference(
-            c.COLS_NOT_FOR_PROMPT_INTERPOLATION
+        prompt_parsing_error_message_area = st.empty()
+        col1, col2 = st.columns([3, 1])
+        cols_for_interpolation = list(
+            set(st.session_state.df.columns).difference(c.COLS_NOT_FOR_PROMPT_INTERPOLATION)
         )
         col1.write(
             f"These are the columns available in the data, feel free to include them in "
-            f"your prompt: {cols_for_interpolation}"
+            f"your prompt(s): `{'`, `'.join(cols_for_interpolation)}`."
         )
+        with col2:
+            st.toggle(label="show prompt preview", value=False, key="show_prompt_preview")
+
+        if st.session_state.show_prompt_preview:
+            col1, col2 = st.columns([3, 2])
+            set_up_prompt_preview(
+                col1,
+                st.session_state.system_prompt,
+                prompt_parsing_error_message_area,
+                prompt_kind="system",
+            )
+            set_up_prompt_preview(
+                col2,
+                st.session_state.user_prompt,
+                prompt_parsing_error_message_area,
+                prompt_kind="user",
+            )
 
-    col2.button(
+    st.button(
         label="Run prompt",
         on_click=run_prompt,
         kwargs={"progress_ui_area": progress_ui_area},
@@ -488,29 +508,64 @@ def _get_coloured_patch(patch):
     )
 
 
-def set_up_prompt_attrs_area(st_container):
-    env = u.jinja_env()
-    parsed_content = env.parse(st.session_state.system_prompt)
-    vars = meta.find_undeclared_variables(parsed_content)
+def set_up_prompt_vars_area(st_container, error_container):
+    try:
+        parsed_content = u.jinja_env().parse(
+            st.session_state.system_prompt + st.session_state.user_prompt
+        )
+        used_vars = meta.find_undeclared_variables(parsed_content)
+    except Exception as e:
+        traceback = u.format_traceback_for_markdown(tb.format_exc())
+        error_container.error(
+            f"Couldn't parse the Jinja templates in the prompt(s). Ensure the "
+            f"templates are valid. Short error message: {e}\n\n"
+            f"Full error message:\n\n{traceback}"
+        )
+        used_vars = set()
 
-    if c.TEXT_ORIG_COL in vars:
-        vars.remove(c.TEXT_ORIG_COL)
+    if c.TEXT_ORIG_COL in used_vars:
+        used_vars.remove(c.TEXT_ORIG_COL)
 
-    if len(vars) > 0:
+    if len(used_vars) > 0:
         # create text of used prompt's variables and their values
         vars_values = ""
-        for var in vars:
+        for var in used_vars:
             vars_values += var + ":\n    " + st.session_state.row.get(var, "none") + "\n"
 
         st_container.text_area(
-            label=f"Attributes used in a prompt",
+            label=f"Attributes other than `{c.TEXT_ORIG_COL}` used in the prompt(s)",
             key="attributes",
             value=vars_values,
             disabled=True,
             height=c.DATA_POINT_TEXT_AREA_HEIGHT,
         )
 
 
+def set_up_prompt_preview(st_container, prompt, error_container, prompt_kind="system"):
+    if "row" in st.session_state:
+        try:
+            prompt = u.jinja_env().from_string(prompt).render(**st.session_state.row.to_dict())
+        except Exception as e:
+            traceback = u.format_traceback_for_markdown(tb.format_exc())
+            error_container.error(
+                f"Couldn't show {prompt_kind} prompt preview due to an error "
+                f"when parsing and rendering the Jinja templates. Ensure that "
+                f"your templates are valid. Short error message: {e}\n\n"
+                f"Full error message:\n\n{traceback}"
+            )
+            prompt = "ERROR"
+    else:
+        prompt = ""
+
+    st_container.text_area(
+        label=f"{prompt_kind.title()} prompt preview",
+        key=f"{prompt_kind}_prompt_jinja2",
+        value=prompt,
+        disabled=True,
+        height=c.PROMPT_PREVIEW_TEXT_AREA_HEIGHT,
+    )
+
+
 def display_image(st_container, base64_str):
     st_container.markdown(
         f"""
@@ -592,15 +647,16 @@ def _handle_skip_past_label_rows_toggle():
 
 
 def set_up_ui_labelling():
+    prompt_parsing_error_message_area = st.empty()
     col1_orig, col2_orig = st.columns([1, 1])
     text_orig_length = len(st.session_state.get("text_orig", ""))
     col1_orig.text_area(
-        label=f"Original text ({text_orig_length} chars)",
+        label=f"Original text (`{c.TEXT_ORIG_COL}` column) ({text_orig_length} chars)",
         key="text_orig",
         disabled=True,
         height=c.DATA_POINT_TEXT_AREA_HEIGHT,
     )
-    set_up_prompt_attrs_area(col2_orig)
+    set_up_prompt_vars_area(col2_orig, prompt_parsing_error_message_area)
 
     if "image" in st.session_state.row:
         display_image(col2_orig, st.session_state.row["image"])