admin: associate inline field errors with their inputs

network assignment rows, activity filters, and the settings password pair now mark the offending input with aria-invalid and point it at the error text with aria-describedby. the prefix validator returns the row and field it is about, and any row mutation clears a message that named a position. settings numeric fields carry aria-invalid on an unparseable value.

admin/src/features/clients/NetworkAssignments.tsx

@@ -4,7 +4,15 @@ import * as stylex from "@stylexjs/stylex";
 import { clientPrefixesPutMutation } from "@/lib/queries";
 import type { ClientPrefix, Group } from "@/lib/types";
 import { defaultGroupId } from "@/lib/defaultGroup";
-import { firstProblem, initPrefixEditor, isDirty, prefixEditorReducer, toInputs } from "./prefixEditor";
+import {
+	firstProblem,
+	initPrefixEditor,
+	isDirty,
+	prefixEditorReducer,
+	toInputs,
+	type PrefixEditorAction,
+	type PrefixProblem,
+} from "./prefixEditor";
 import InlineError from "@/lib/InlineError";
 import AuthorityGate from "@/features/configuration/AuthorityGate";
 import Select from "@/ui/Select";
@@ -16,6 +24,9 @@ interface Props {
 	groups: Group[];
 }
 
+/** The editor is rendered once per page, so the message can hold a fixed id. */
+const VALIDATION_ID = "network-assignments-validation";
+
 const styles = stylex.create({
 	section: {
 		marginTop: "2.5rem",
@@ -162,12 +173,24 @@ function AssignmentsTable({ prefixes }: { prefixes: ClientPrefix[] }) {
 function AssignmentsEditor({ prefixes, groups }: Props) {
 	const queryClient = useQueryClient();
 	const mutation = useMutation(clientPrefixesPutMutation(queryClient));
-	const [state, dispatch] = useReducer(prefixEditorReducer, prefixes, initPrefixEditor);
-	const [validation, setValidation] = useState<string | null>(null);
+	const [state, apply] = useReducer(prefixEditorReducer, prefixes, initPrefixEditor);
+	const [validation, setValidation] = useState<PrefixProblem | null>(null);
 	const dirty = isDirty(state);
 	const fallbackGroupId = defaultGroupId(groups);
 	const groupOptions = groups.map((group) => ({ value: String(group.id), label: group.name }));
 
+	// A problem names a row by position, and every action here can move, add or
+	// delete a position. The message describes the rows Save read, so it dies
+	// with them rather than drifting onto whatever row inherits the index.
+	const dispatch = (action: PrefixEditorAction) => {
+		setValidation(null);
+		apply(action);
+	};
+
+	/** True for the one input the current message is about; nothing else is marked. */
+	const invalid = (index: number, field: PrefixProblem["field"]): true | undefined =>
+		validation !== null && validation.index === index && validation.field === field ? true : undefined;
+
 	const save = () => {
 		const problem = firstProblem(state.rows);
 		setValidation(problem);
@@ -188,6 +211,8 @@ function AssignmentsEditor({ prefixes, groups }: Props) {
 							<input
 								type="text"
 								aria-label={`Range ${index + 1}`}
+								aria-invalid={invalid(index, "prefix")}
+								aria-describedby={invalid(index, "prefix") && VALIDATION_ID}
 								placeholder="192.168.1.0/24"
 								value={row.prefix}
 								onChange={(event) =>
@@ -208,6 +233,8 @@ function AssignmentsEditor({ prefixes, groups }: Props) {
 								type="text"
 								inputMode="numeric"
 								aria-label={`Priority for range ${index + 1}`}
+								aria-invalid={invalid(index, "priority")}
+								aria-describedby={invalid(index, "priority") && VALIDATION_ID}
 								placeholder="100"
 								value={row.priority}
 								onChange={(event) =>
@@ -227,8 +254,8 @@ function AssignmentsEditor({ prefixes, groups }: Props) {
 				</ul>
 			)}
 			{validation !== null && (
-				<p role="alert" {...stylex.props(styles.validation)}>
-					{validation}
+				<p id={VALIDATION_ID} role="alert" {...stylex.props(styles.validation)}>
+					{validation.message}
 				</p>
 			)}
 			<InlineError error={mutation.error} />
@@ -251,10 +278,7 @@ function AssignmentsEditor({ prefixes, groups }: Props) {
 				{dirty && (
 					<button
 						type="button"
-						onClick={() => {
-							setValidation(null);
-							dispatch({ type: "reset", prefixes });
-						}}
+						onClick={() => dispatch({ type: "reset", prefixes })}
 						{...stylex.props(shared.button, shared.focusRing)}
 					>
 						Discard changes