DataGridHasOneColumn offers include/exclude on an empty has-one cell and filters on a placeholder id

[matej21]

Summary

DataGridHasOneColumn offers the include/exclude filter actions on a cell whose nullable has-one relation is empty. The actions filter on the relation's disconnected placeholder id (__placeholder_…), so „Exclude" sends { not: { <field>: { id: { eq: "__placeholder_…" } } } }. A Contember engine rejects that value as an invalid id, and the grid fails to load.

Environment

• @contember/bindx@0.1.52 / @contember/bindx-ui@0.1.52 (version installed in the reporting project); the code is unchanged in 0.1.53
• Reproduces on contember/bindx@main as of 7ae3d15
• Failing test: tests/react/dataview/hasOneColumnEmptyCellFilter.test.tsx
• Branch: bug/has-one-column-empty-cell-filter

Reproduction

// Article.author is hasOne('Author', { nullable: true }); one row has author: null
<DataGrid entity={schema.Article}>
	{it => (
		<>
			<DataGridHasOneColumn field={it.author} header="Author">
				{author => author.name.value ?? '—'}
			</DataGridHasOneColumn>
			<DataGridAutoTable />
		</>
	)}
</DataGrid>

The test asserts that the connected cell has a [data-bindx-tooltip] trigger and the empty cell has none. The second assertion fails.

Expected behavior

A cell with no related entity renders its content without the filter affordance. This is what the if (!id) return content branch in renderCellWrapper intends. A filter value must be an id the server knows.

Actual behavior

The empty cell („—") is wrapped in DataGridHasOneTooltip with id="__placeholder_<uuid>". Hovering it shows „Filter" / „Exclude". Clicking „Exclude" stores notId: ["__placeholder_<uuid>"]. The has-one filter handler turns it into { not: { author: { id: { eq: "__placeholder_<uuid>" } } } }, which the engine rejects (not a UUID). „Filter" produces the same invalid eq condition.

Suspected root cause

packages/bindx-ui/src/datagrid/columns/has-one-column.tsx:108-110:

renderCellWrapper: ({ content, item, fieldName, filterName, fieldRef }: RelationCellWrapperContext) => {
	const id = getRelatedAccessor(item, fieldName)?.id ?? null
	if (!id) return content

For a disconnected has-one, getRelatedAccessor returns the relation handle, and HasOneHandle.id (packages/bindx/src/handles/HasOneHandle.ts:292-299) returns the placeholder id, which is truthy. So the guard never triggers.

has-many-column.tsx has the same code, but a has-many handle exposes no id, so that wrapper returns content for every cell and this bug does not affect it.

Suggested fix

Guard on a persisted id. Select.tsx and select-field.tsx already check isPlaceholderId for the same reason:

const id = getRelatedAccessor(item, fieldName)?.id
if (!id || !isPersistedId(id)) return content

isPersistedId also excludes a temporary id, which the server cannot filter on either. The empty value stays filterable through the column's „N/A" (null) filter.

Workaround shipped downstream

None. The reporting project waits for a release with the fix; a PR with the fix follows.