Simplify interface for getting contexts.

src/codehelp/helper.py

@@ -26,7 +26,6 @@
 )
 from gened.classes import switch_class
 from gened.contexts import (
-    ContextNotFoundError,
     get_available_contexts,
     get_context_by_name,
 )
@@ -55,21 +54,20 @@ def help_form(query_id: int | None = None, class_id: int | None = None, ctx_name
         success = switch_class(class_id)
         if not success:
             # Can't access the specified context
-            flash(f"Cannot access class and context.  Make sure you are logged in correctly before using this link.", "danger")
+            flash("Cannot access class and context.  Make sure you are logged in correctly before using this link.", "danger")
             return make_response(render_template("error.html"), 400)
 
     # we may select a context from a given ctx_name, from a given query_id, or from the user's most recently-used context
     selected_context_name = None
     query_row = None
     if ctx_name is not None:
         # see if the given context is part of the current class (whether available or not)
-        try:
-            context = get_context_by_name(CodeHelpContext, ctx_name)
-            contexts_list = [context]  # this will be the only context in this page -- no other options
-            selected_context_name = ctx_name
-        except ContextNotFoundError:
+        context = get_context_by_name(CodeHelpContext, ctx_name)
+        if context is None:
             flash(f"Context not found: {ctx_name}", "danger")
             return make_response(render_template("error.html"), 404)
+        contexts_list = [context]  # this will be the only context in this page -- no other options
+        selected_context_name = ctx_name
     else:
         contexts_list = get_available_contexts(CodeHelpContext)  # all *available* contexts will be shown
         if query_id is not None:
@@ -86,11 +84,11 @@ def help_form(query_id: int | None = None, class_id: int | None = None, ctx_name
 
         # verify the context is real and part of the current class
         if selected_context_name is not None:
-            try:
-                context = get_context_by_name(CodeHelpContext, selected_context_name)
-                contexts_list.append(context)  # add this context to the list - may be hidden - if duplicate, dict comprehension will automatically filter
-            except ContextNotFoundError:
+            context = get_context_by_name(CodeHelpContext, selected_context_name)
+            if context is None:
                 selected_context_name = None
+            else:
+                contexts_list.append(context)  # add this context to the list - may be hidden - if duplicate, dict comprehension will automatically filter
 
     # turn contexts into format we can pass to js via JSON
     contexts = {ctx.name: ctx.desc_html() for ctx in contexts_list}
@@ -229,9 +227,8 @@ def record_response(query_id: int, responses: list[dict[str, str]], texts: dict[
 @with_llm()
 def help_request(llm_dict: LLMDict) -> Response:
     if 'context' in request.form:
-        try:
-            context = get_context_by_name(CodeHelpContext, request.form['context'])
-        except ContextNotFoundError:
+        context = get_context_by_name(CodeHelpContext, request.form['context'])
+        if context is None:
             flash(f"Context not found: {request.form['context']}")
             return make_response(render_template("error.html"), 400)
     else:

src/codehelp/tutor.py

@@ -19,7 +19,6 @@
 from gened.admin import register_admin_link
 from gened.auth import get_auth, login_required
 from gened.contexts import (
-    ContextNotFoundError,
     get_available_contexts,
     get_context_by_name,
 )
@@ -72,11 +71,14 @@ def tutor_form() -> str:
 @with_llm()
 def start_chat(llm_dict: LLMDict) -> Response:
     topic = request.form['topic']
-    try:
+
+    if 'context' in request.form:
         context = get_context_by_name(CodeHelpContext, request.form['context'])
-    except ContextNotFoundError:
-        flash(f"Context not found: {request.form['context']}")
-        return make_response(render_template("error.html"), 400)
+        if context is None:
+            flash(f"Context not found: {request.form['context']}")
+            return make_response(render_template("error.html"), 400)
+    else:
+        context = None
 
     chat_id = create_chat(topic, context)
 
@@ -116,16 +118,22 @@ def chat_interface(chat_id: int) -> str | Response:
     return render_template("tutor_view.html", chat_id=chat_id, topic=topic, context_name=context_name, chat=chat, chat_history=chat_history)
 
 
-def create_chat(topic: str, context: CodeHelpContext) -> int:
+def create_chat(topic: str, context: CodeHelpContext | None) -> int:
+    db = get_db()
     auth = get_auth()
     user_id = auth['user_id']
     role_id = auth['role_id']
-    context_string_id = record_context_string(context.prompt_str())
 
-    db = get_db()
+    if context is not None:
+        context_name = context.name
+        context_string_id = record_context_string(context.prompt_str())
+    else:
+        context_name = None
+        context_string_id = None
+
     cur = db.execute(
         "INSERT INTO chats (user_id, role_id, topic, context_name, context_string_id, chat_json) VALUES (?, ?, ?, ?, ?, ?)",
-        [user_id, role_id, topic, context.name, context_string_id, json.dumps([])]
+        [user_id, role_id, topic, context_name, context_string_id, json.dumps([])]
     )
     new_row_id = cur.lastrowid
 

src/gened/contexts.py

@@ -309,11 +309,10 @@ def get_available_contexts(ctx_class: type[T]) -> list[T]:
     return [ctx_class.from_row(row) for row in context_rows]
 
 
-class ContextNotFoundError(Exception):
-    pass
-
-
-def get_context_config_by_id(ctx_class: type[T], ctx_id: int) -> T:
+def get_context_config_by_id(ctx_class: type[T], ctx_id: int) -> T | None:
+    """ Return a context object of the given class based on the specified id
+        or return None if no context exists with that name.
+    """
     assert _context_class is not None
 
     db = get_db()
@@ -324,12 +323,15 @@ def get_context_config_by_id(ctx_class: type[T], ctx_id: int) -> T:
     context_row = db.execute("SELECT * FROM contexts WHERE class_id=? AND id=?", [class_id, ctx_id]).fetchone()
 
     if not context_row:
-        raise ContextNotFoundError
+        return None
 
     return ctx_class.from_row(context_row)
 
 
-def get_context_by_name(ctx_class: type[T], ctx_name: str) -> T:
+def get_context_by_name(ctx_class: type[T], ctx_name: str) -> T | None:
+    """ Return a context object of the given class based on the specified name
+        or return None if no context exists with that name.
+    """
     assert _context_class is not None
 
     db = get_db()
@@ -340,6 +342,6 @@ def get_context_by_name(ctx_class: type[T], ctx_name: str) -> T:
     context_row = db.execute("SELECT * FROM contexts WHERE class_id=? AND name=?", [class_id, ctx_name]).fetchone()
 
     if not context_row:
-        raise ContextNotFoundError
+        return None
 
     return ctx_class.from_row(context_row)