tldraw SDK

Table of contents

migrations
props
type
editor
Properties
Methods

abstract class BindingUtil<
  Binding extends TLUnknownBinding = TLUnknownBinding,
> {}

Constructor

Constructs a new instance of the BindingUtil class

Parameters

Name	Description
`editor`	`Editor`

Properties

migrations

staticoptional

static migrations?: TLPropsMigrations

props

staticoptional

static props?: RecordProps<TLUnknownBinding>

type

static

The type of the binding util, which should match the binding's type.

static type: string

editor

editor: Editor

Methods

getDefaultProps()

Get the default props for a binding.

abstract getDefaultProps(): Partial<Binding['props']>

onAfterChange()

optional

Called after a binding has been changed. See BindingOnChangeOptions for details.

Note that this only fires when the binding record is changing, not when the shapes associated change. Use BindingUtil.onAfterChangeFromShape and BindingUtil.onAfterChangeToShape for that.

onAfterChange?(options: BindingOnChangeOptions<Binding>): void

Parameters

Name	Description
`options`	`BindingOnChangeOptions<Binding>`

Returns

void

onAfterChangeFromShape()

optional

Called after the shape referenced in a binding's fromId is changed. Use this to propagate any changes to the binding itself or the other shape as needed. See BindingOnShapeChangeOptions for details.

onAfterChangeFromShape?(options: BindingOnShapeChangeOptions<Binding>): void

Parameters

Name	Description
`options`	`BindingOnShapeChangeOptions<Binding>`

Returns

void

onAfterChangeToShape()

optional

Called after the shape referenced in a binding's toId is changed. Use this to propagate any changes to the binding itself or the other shape as needed. See BindingOnShapeChangeOptions for details.

onAfterChangeToShape?(options: BindingOnShapeChangeOptions<Binding>): void

Parameters

Name	Description
`options`	`BindingOnShapeChangeOptions<Binding>`

Returns

void

onAfterCreate()

optional

Called after a binding has been created. See BindingOnCreateOptions for details.

onAfterCreate?(options: BindingOnCreateOptions<Binding>): void

Parameters

Name	Description
`options`	`BindingOnCreateOptions<Binding>`

Returns

void

onAfterDelete()

optional

Called after a binding has been deleted. See BindingOnDeleteOptions for details.

onAfterDelete?(options: BindingOnDeleteOptions<Binding>): void

Parameters

Name	Description
`options`	`BindingOnDeleteOptions<Binding>`

Returns

void

onBeforeChange()

optional

Called when a binding is about to be changed. See BindingOnChangeOptions for details.

Note that this only fires when the binding record is changing, not when the shapes associated change. Use BindingUtil.onAfterChangeFromShape and BindingUtil.onAfterChangeToShape for that.

You can optionally return a new binding to replace the one being changed - for example, to enforce constraints on the binding's props.

onBeforeChange?(options: BindingOnChangeOptions<Binding>): Binding | void

Parameters

Name	Description
`options`	`BindingOnChangeOptions<Binding>`

Returns

Binding | void

onBeforeCreate()

optional

Called when a binding is about to be created. See BindingOnCreateOptions for details.

You can optionally return a new binding to replace the one being created - for example, to set different initial props.

onBeforeCreate?(options: BindingOnCreateOptions<Binding>): Binding | void

Parameters

Name	Description
`options`	`BindingOnCreateOptions<Binding>`

Returns

Binding | void

onBeforeDelete()

optional

Called when a binding is about to be deleted. See BindingOnDeleteOptions for details.

onBeforeDelete?(options: BindingOnDeleteOptions<Binding>): void

Parameters

Name	Description
`options`	`BindingOnDeleteOptions<Binding>`

Returns

void

onBeforeDeleteFromShape()

optional

Called before the shape referenced in a binding's fromId is about to be deleted. Use this with care - you may want to use BindingUtil.onBeforeIsolateToShape instead. See BindingOnShapeDeleteOptions for details.

onBeforeDeleteFromShape?(options: BindingOnShapeDeleteOptions<Binding>): void

Parameters

Name	Description
`options`	`BindingOnShapeDeleteOptions<Binding>`

Returns

void

onBeforeDeleteToShape()

optional

Called before the shape referenced in a binding's toId is about to be deleted. Use this with care - you may want to use BindingUtil.onBeforeIsolateFromShape instead. See BindingOnShapeDeleteOptions for details.

onBeforeDeleteToShape?(options: BindingOnShapeDeleteOptions<Binding>): void

Parameters

Name	Description
`options`	`BindingOnShapeDeleteOptions<Binding>`

Returns

void

onBeforeIsolateFromShape()

optional

Called before the shape referenced in a binding's fromId is about to be isolated from the shape referenced in toId. See BindingOnShapeIsolateOptions for discussion on what isolation means, and when/how to use this callback.

onBeforeIsolateFromShape?(
  options: BindingOnShapeIsolateOptions<Binding>
): void

Parameters

Name	Description
`options`	`BindingOnShapeIsolateOptions<Binding>`

Returns

void

onBeforeIsolateToShape()

optional

Called before the shape referenced in a binding's toId is about to be isolated from the shape referenced in fromId. See BindingOnShapeIsolateOptions for discussion on what isolation means, and when/how to use this callback.

onBeforeIsolateToShape?(options: BindingOnShapeIsolateOptions<Binding>): void

Parameters

Name	Description
`options`	`BindingOnShapeIsolateOptions<Binding>`

Returns

void

onOperationComplete()

optional

Called whenever a store operation involving this binding type has completed. This is useful for working with networks of related bindings that may need to update together.

onOperationComplete?(): void

Example

class MyBindingUtil extends BindingUtil<MyBinding> {
  changedBindingIds = new Set<TLBindingId>()

  onOperationComplete() {
    doSomethingWithChangedBindings(this.changedBindingIds)
    this.changedBindingIds.clear()
  }

  onAfterChange({ bindingAfter }: BindingOnChangeOptions<MyBinding>) {
    this.changedBindingIds.add(bindingAfter.id)
  }
}