Skip to content
Mateu

Compare and merge records

Status: ✅ Implemented · @Experimental

Two duplicate guest profiles side by side, the rows that differ highlighted

Intent

Section titled “Intent”

Some decisions are taken field by field over two versions of the same thing: merging duplicate customer profiles, resolving an edit conflict (your version against the stored one), reviewing what a sync is about to overwrite. A form with one radio per attribute works, but it reads like a form; the screen people know shows the records in columns, marks what differs and lets them pick a side for each row.

Solution

Section titled “Solution”

Return a RecordMerge anywhere in the page’s components: one MergeRecord per column, one MergeField per row with the row’s value in each record (in the records’ order), and the action that merges.

RecordMerge.builder()
        .title("Guest profiles 1021 and 3388 look like the same person")
        .records(List.of(
                new MergeRecord("1021", "Profile 1021", "Created 3 Mar 2021 · 12 stays"),
                new MergeRecord("3388", "Profile 3388", "Created 9 Sep 2026 · 1 stay")))
        .fields(List.of(
                MergeField.of("lastName", "Last name", "García López", "Garcia"),
                MergeField.of("email", "Email", null, "ana.garcia@example.com"),
                MergeField.of("phone", "Phone", "+34 600 111 222", "+34 699 333 444").withEditable(true),
                MergeField.of("address", "Address", "C/ Mayor 1", "Calle Mayor 1, 07001 Palma")
                        .withEditable(true).withChosen("3388")))
        .mergeActionId("mergeProfiles")
        .mergeLabel("Merge into profile 1021")
        .parameters(Map.of("survivor", "1021", "duplicate", "3388"))
        .build()

The merge action receives the picks next to the component’s own parameters:

ParameterValue
_mergedfieldId → value: the resulting record
_choicesfieldId → record id it was taken from, or "custom" when it was typed
public Object mergeProfiles(HttpRequest httpRequest) {
    var parameters = httpRequest.runActionRq().parameters();
    var merged = (Map<String, Object>) parameters.get("_merged");
    customers.merge((String) parameters.get("survivor"), (String) parameters.get("duplicate"), merged);
    return new Message("Profiles merged");
}

The server settles what every renderer would otherwise compute on its own: each row is padded (or cut) to one value per record, a row differs when its values are not all the same (compared as trimmed text; a missing value is blank), and the value picked to begin with is the one withChosen names or else the first record with a value. The picks themselves are client-side state — nothing reaches the server until the merge.

Options

Section titled “Options”
ParameterEffect
recordsthe columns, in order — two or more
fieldsthe rows; MergeField.of(id, label, values…), withChosen(recordId), withEditable(true)
differencesOnlythe Show only differences switch starts on
mergeLabelthe button’s label (default Merge)
parameterssent with the merge action, next to _merged / _choices

Accessibility

Section titled “Accessibility”

Each row is a native radio group, so it works with the keyboard as is: Tab moves between rows, the arrow keys pick within one. Every pick has a full name — “Use value from Profile 3388 for Email” — and a differing row says differs in text, not only in colour. The summary under the result (“7 fields: 5 differ; 1 typed by hand”) is a polite live region.

Where it works

Section titled “Where it works”
  • Vaadin — the shared mateu-record-merge element (a table, scrolling sideways when the records do not fit).
  • Redwood (Oracle VB) — the RecordMerge atom on Redwood tokens.
  • React Native — one card per field (columns do not fit a phone), the same picks and summary.
  • IntelliJ plugin — a Swing grid with a button group per row.
  • Also from the C# (new RecordMerge { … }) and Python (RecordMerge(...)) backends, and from YAML (type: RecordMerge).

Demo: demo-admin-panel → /record-merge-demo (also F9, or MRG in the command center).

Section titled “Related”