Fix: Response not iterable on trigger expansion

[kundansable]

Summary

Fixes #10117 — expanding a Trigger node under a Table to view its trigger function throws 'Response' object is not iterable, crashing the tree instead of showing the function (or a clean error).

Root Cause

Two separate bugs on the same code path, TriggerView.get_children_nodes():

1. The reported crash: get_children_nodes() can legitimately return a Flask Response instead of a list — e.g. gone("Could not find the specified trigger function") when the trigger's function has no matching row in the trigger-function node query (see #2). NodeView.children() / PGChildNodeView.children() unconditionally called sorted(...) on whatever get_children_nodes() returned, so a Response blew up with 'Response' object is not iterable instead of being passed through.
2. A masked regression found while testing the fix for ISSUE2277-Internal server error displayed if table name contains long character #1: the render_template() call that builds the trigger-function node.sql query never passed conn= into the template context, even though the template quotes fnid via {{ fnid|qtLiteral(conn) }}. This call site predates qtLiteral requiring a connection; after qtLiteral was hardened (in 658bb585d) to raise ValueError instead of silently degrading when conn is missing, this call started raising on every trigger expansion (not just the internal-language case), which is what actually surfaced while verifying fix ISSUE2277-Internal server error displayed if table name contains long character #1 — before that, it looked like every trigger's function node was broken with a qtLiteral requires a connection 500 error, masking the narrower, real 'Response' object is not iterable #10117 repro underneath.

Fix

1. In NodeView.children() and PGChildNodeView.children() (web/pgadmin/browser/utils.py), check isinstance(children, flask.Response) before sorting/iterating, and return the Response as-is when it is one.
2. In TriggerView.get_children_nodes() (web/pgadmin/browser/server_groups/servers/databases/schemas/tables/triggers/__init__.py), pass conn=self.conn into the node.sql render call, matching every other render_template call site in the file.

Test Steps

1. Run the following against a test database — it creates a table with two triggers, one using a genuine PostgreSQL built-in internal-language trigger function, and one using a normal plpgsql trigger function:

   CREATE TABLE trigger_bug_test (id int PRIMARY KEY, val text);
   
   -- Built into every PostgreSQL server since 9.0, LANGUAGE internal.
   CREATE FUNCTION my_redundant_trigger() RETURNS trigger LANGUAGE internal
     AS 'suppress_redundant_updates_trigger';
   CREATE TRIGGER trg_suppress_redundant BEFORE UPDATE ON trigger_bug_test
     FOR EACH ROW EXECUTE FUNCTION my_redundant_trigger();
   
   -- A normal, ordinary plpgsql trigger function.
   CREATE FUNCTION trg_normal_plpgsql_fn() RETURNS trigger LANGUAGE plpgsql AS $$
   BEGIN
       NEW.val := coalesce(NEW.val, '') || '_touched';
       RETURN NEW;
   END;
   $$;
   CREATE TRIGGER trg_normal_plpgsql BEFORE INSERT ON trigger_bug_test
     FOR EACH ROW EXECUTE FUNCTION trg_normal_plpgsql_fn();

2. In the Object Explorer, expand trigger_bug_test > Triggers > trg_suppress_redundant.
   • Before the fix: 'Response' object is not iterable.
   • After the fix: a clean "Could not find the specified trigger function" message — expected, since pgAdmin can't browse internal-language function source; no crash.
3. Expand trigger_bug_test > Triggers > trg_normal_plpgsql.
   • Before the conn=self.conn fix: qtLiteral requires a connection 500 error.
   • After the fix: expands normally and shows the trg_normal_plpgsql_fn() function node.
4. Regression: expand a trigger on any other existing table in the test database and confirm its function node still displays correctly.

Summary by CodeRabbit

• Bug Fixes
  • Improved error handling when loading browser tree nodes, ensuring error responses are displayed correctly instead of causing additional processing failures.
  • Improved trigger-function detail loading for database trigger nodes.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro Plus

Run ID: ed441c7b-edeb-4fc9-86c3-9a7fe711b8aa

📥 Commits

Reviewing files that changed from the base of the PR and between b15c745 and fdfd6ff.

📒 Files selected for processing (2)

• web/pgadmin/browser/server_groups/servers/databases/schemas/tables/triggers/__init__.py
• web/pgadmin/browser/utils.py

---

Walkthrough

Trigger-function SQL rendering now receives the active connection. Browser child-node methods detect Flask responses and return them directly, while preserving sorting and JSON response handling for normal node lists.

Changes

Trigger response handling

Layer / File(s)	Summary
Trigger query connection context web/pgadmin/browser/server_groups/servers/databases/schemas/tables/triggers/__init__.py	The trigger SQL template receives self.conn together with the function identifier.
Response-safe child traversal web/pgadmin/browser/utils.py	NodeView.children and PGChildNodeView.children return Flask Response objects directly and continue sorting and wrapping normal node lists as JSON.

Estimated code review effort: 2 (Simple) | ~10 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly summarizes the main fix for trigger expansion returning a Response.
Linked Issues check	✅ Passed	The changes address issue #10117 by returning Response objects directly and fixing trigger-function rendering.
Out of Scope Changes check	✅ Passed	No unrelated code changes are evident; both modifications support the trigger expansion fix.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands.}