CanConnectOptions

Options for the validateConnection prop of <Paper> — declarative rules that toggle the common connection constraints (self-loops, link-to-link, duplicate links, root connections) and optionally layer your own check on top. Reach for this object instead of a ValidateConnection callback when the built-in rules already cover what you need.

Example

import { GraphProvider, Paper } from '@joint/react';

<GraphProvider>
  <Paper
    validateConnection={{
      allowSelfLoops: true,
      validate: ({ target }) => target.port === 'in',
    }}
    renderElement={() => <rect width={80} height={40} />}
  />
</GraphProvider>;

Properties

allowLinkToLink?

readonly optional allowLinkToLink?: boolean;

Allow links to start or end on another link, not just on elements.

Default

false

---

allowRootConnection?

readonly optional allowRootConnection?: boolean | "auto";

Whether a link may attach to an element's root (its body) instead of a port or magnet.

• true — always allow root connections.
• false — never allow them; require a port or magnet.
• 'auto' — allow a root connection only when the element has no ports.

Default

'auto'

---

allowSelfLoops?

readonly optional allowSelfLoops?: boolean;

Allow a cell to connect to itself.

Default

false

---

linkLimit?

readonly optional linkLimit?: "none" | "one-per-direction" | "one-per-pair";

How many links may connect the same source+port and target+port. Matching is port/magnet aware, so links on different ports never collide.

• 'none' — no limit; any number of links, in either direction.
• 'one-per-direction' — one link each way: a second A→B is blocked, but the reverse B→A is allowed.
• 'one-per-pair' — one link per element pair: A→B blocks both another A→B and the reverse B→A.

Default

'one-per-direction'

---

validate?

readonly optional validate?: (context) => boolean;

Extra check run only after every built-in rule passes; receives the same ValidateConnectionParams context as ValidateConnection.

Parameters

Parameter	Type
context	ValidateConnectionParams

Returns

boolean