ALTER PAGE: column property aliases are case-sensitive (caption fails, Caption works)

[ako]

Summary

ALTER PAGE column property SET fails for lowercase property names — set caption = '…' on grid.col returns column property "caption" not found, while set Caption = '…' on grid.col works. The columnPropertyAliases map in mdl/backend/mpr/page_mutator.go is case-sensitive on the MDL-facing side, but the skill docs and natural MDL style use lowercase.

Reproduction

alter page MyMod.Product_Overview {
  set caption = 'Name' on dgProducts.Name
};

Error:

Error: failed to set: failed to set caption on dgProducts.Name: column property "caption" not found

Works:

alter page MyMod.Product_Overview {
  set Caption = 'Name' on dgProducts.Name
};

Mismatch with docs

.claude/skills/mendix/alter-page.md (line 135) shows:

-- SET a column property
set caption = 'Product SKU' on dgProducts.Code

The skill example doesn't work; the actual implementation requires Caption.

Root cause

mdl/backend/mpr/page_mutator.go:1437 — columnPropertyAliases is keyed by capitalized MDL names mapping to lowercase BSON property keys:

var columnPropertyAliases = map[string]string{
    "Caption":       "header",       // MDL → BSON
    "Visible":       "visible",
    "Alignment":     "alignment",
    "ShowContentAs": "showContentAs",
    // …
}

The lookup at line 1454 is exact-match, so caption (lowercase) falls through to internalKey = "caption" and doesn't resolve to the internal header key.

Suggested fix

The BSON-internal property keys (right side of the map) must stay case-sensitive — those are dictated by the DataGrid2 widget schema (header, visible, showContentAs, etc.) and cannot be changed.

The MDL-facing property names (left side) should be case-insensitive. Users will reasonably type either caption or Caption. Fix:

// One-time init: build lowercase-keyed alias map for case-insensitive lookup.
var columnPropertyAliasesCI = func() map[string]string {
    m := make(map[string]string, len(columnPropertyAliases))
    for k, v := range columnPropertyAliases {
        m[strings.ToLower(k)] = v
    }
    return m
}()

func setColumnPropertyMut(...) error {
    internalKey := columnPropertyAliasesCI[strings.ToLower(propName)]
    if internalKey == "" {
        internalKey = propName
    }
    // …
}

BSON storage stays exactly as-is; only the lookup becomes case-insensitive.

Discovered

While building `mdl-examples/doctype-tests/33-alter-page-examples.mdl` (commit 01ad80e0).

[github-actions]

Issue Triage

Summary
The ALTER PAGE command fails to set lowercase column properties (e.g., caption) because the property‑alias lookup is case‑sensitive, while the documentation and natural MDL style use lowercase.

Checklist of required bug‑report information

Required info	Present?	Notes
mxcli version	❌	Not mentioned
Mendix version	❌	Not mentioned
Scenario (what the user was trying to do)	✅	MDL alter page … set caption = … shown
Expected output	✅	Property should be set without error
Experienced output (error message, etc.)	✅	Error: column property "caption" not found
AI bug report (mxcli diag --bundle or session log)	❌	Not provided

What’s missing
To help us reproduce and fix the issue, could you please add:

1. The version of mxcli you’re using (mxcli --version or commit/build info).
2. The Mendix version of the project you’re processing (e.g., 10.6, 9.24).
3. A diagnostic bundle or at least the session log from mxcli diag --bundle (or the relevant log excerpt).

Once we have those details, we’ll be able to investigate further. Thanks for reporting this!

---

Automated triage via OpenRouter — workflow source

[ako]

Fixed in commit e2ec894a.

Turned out to be two bugs once the first was unblocked:

1. Case-sensitive alias lookup — added columnPropertyAliasesCI (lowercase-keyed view of columnPropertyAliases) so MDL accepts caption, Caption, CAPTION interchangeably. BSON-internal PropertyKeys (header, visible, …) stay case-sensitive as before.

2. TextTemplate values weren't actually being updated — once the lookup worked, set caption = 'X' succeeded silently but the BSON didn't change. The column header is stored in a nested Forms$ClientTemplate → Texts$Text → Items[Translation].Text structure; the setter was only writing PrimitiveValue. setColumnPropertyMut now detects TextTemplate-valued properties and updates the nested Translation (creating an en_US entry if none exists).

Verified end-to-end with mdl-examples/doctype-tests/33-alter-page-examples.mdl: lowercase set caption = '…' on grid.col now changes the BSON and describe page reflects the new caption.