ALTER PAGE: set Title = '…' returns success but does not update page title

[ako]

Summary

Page-level set Title = '…' in an ALTER PAGE block reports Altered page … but the title in BSON is unchanged. describe page after the SET still shows the old title.

Reproduction

create or replace page Demo.Foo (
  Title: 'Old Title',
  Layout: Atlas_Core.Atlas_Default
) {
  layoutgrid lg1 {
    row r1 {
      column c1 (DesktopWidth: AutoFill) {
        container c (Class: 'x')
      }
    }
  }
};

alter page Demo.Foo {
  set Title = 'New Title'
};

Then:

./bin/mxcli -p app.mpr -c "describe page Demo.Foo"

Output still shows Title: 'Old Title'. The ALTER reports Altered page Demo.Foo so there's no error surfaced.

Root cause (suspected)

mdl/backend/mpr/page_mutator.go:1536 applyPageLevelSetMut handles Title by calling setTranslatableText(rawData, "Title", value). The title in page BSON is stored as a translatable text structure (Texts$Text with Translations[]); setTranslatableText likely needs to either:

• Find the existing Translation entry for the default language and update its Text
• Or replace the entire Title BSON with a new TranslatableText

I haven't dug into setTranslatableText to confirm — could also be hitting the FormCall branch incorrectly (line 1539: if formCall := dGetDoc(rawData, "FormCall"); formCall != nil { setTranslatableText(formCall, "Title", value) }), but pages do have a FormCall wrapper.

Workaround

Re-issue the page with create or replace page and the new title.

Notes

• set Url = '…' is documented but not tested in this repro — may have a similar issue.
• The skill .claude/skills/mendix/alter-page.md documents set title = 'Edit Customer' as supported (line 66 row).

Discovered

While building mdl-examples/doctype-tests/33-alter-page-examples.mdl (commit 01ad80e0); AP01 was originally set Title = 'Products' and was silently no-op'd, prompting removal of that step.

[github-actions]

Issue Triage

Summary
The ALTER PAGE … set Title = '…' command reports success but does not actually update the page title in the BSON data.

Checklist of required bug‑report information

Required info	Present?	Details
mxcli version	❌	Not mentioned
Mendix version	❌	Not mentioned
Scenario (what was tried)	✅	MDL script with ALTER PAGE and mxcli describe page command
Expected output	✅	Title should change to the new value
Experienced output	✅	Title remains unchanged; command reports “Altered page …”
AI bug report (mxcli diag --bundle or session log)	❌	Not provided

What’s missing
To help us investigate, could you please add:

1. The version of mxcli you’re using (output of mxcli --version or commit/build info).
2. The Mendix version of the project you’re editing (e.g., 10.6.0, 9.24.1).
3. If possible, run mxcli diag --bundle and attach the resulting archive, or at least share the session log from the command that failed.

Once we have those details we’ll be able to reproduce the issue and work on a fix. Thank you for reporting this!

---

Automated triage via OpenRouter — workflow source

[ako]

Fixed in commit f005ae14.

Same shape of bug as #560 — two layers had to be peeled back:

1. Wrong parent for Title — applyPageLevelSetMut switched parent to FormCall when present, then wrote Title there. But Title lives at the top level of the Forms$Page document (parallel to FormCall, not nested inside it), so the write landed on a FormCall that has no Title field. The function returned nil, caller saw success.

2. Wrong array name inside the Title doc — Even with the right parent, setTranslatableText was navigating Translations[]. The actual BSON is a Texts$Text doc with Items[] of Texts$Translation entries (LanguageCode + Text).

Fixed by stopping the FormCall wrapping and using a new updateTextsTextValue helper that correctly updates the en_US Translation in Items[] (creating one if none exists). Pattern mirrors updateClientTemplateText from #560.

Verified: set Title = 'New Title' now changes the BSON and describe page reflects it. AP01 in 33-alter-page-examples.mdl exercises this end-to-end.