IDeltaHandler Interface

Handler provided by shared data structure to process requests from the runtime.

This API is provided for existing users, but is not recommended for new users.

To use, import via @fluidframework/datastore-definitions/legacy.

For more information about our API support guarantees, see here.

Signature

export interface IDeltaHandler

Properties

Property	Alerts	Type	Description
processMessages	Beta	(messageCollection: IRuntimeMessageCollection) => void	Process messages for this channel. The messages here are contiguous messages for this channel in a batch.

Methods

Method	Alerts	Modifiers	Return Type	Description
applyStashedOp(message)	Beta		void	Apply changes from an op just as if a local client has made the change, including submitting the op. Used when rehydrating an attached container with pending changes. This prepares the SharedObject for seeing an ACK for the op or resubmitting the op upon reconnection.
reSubmit(message, localOpMetadata, squash)	Beta		void	Called when the runtime asks the client to resubmit an op. This may be because the Container reconnected and this op was not acked. The client can choose to resubmit the same message, submit different / multiple messages or not submit anything at all.
rollback(message, localOpMetadata)	Beta	optional	void	Revert a local op.
setConnectionState(connected)	Beta		void	State change events to indicate changes to the delta connection

Property Details

processMessages

Process messages for this channel. The messages here are contiguous messages for this channel in a batch.

This API is provided for existing users, but is not recommended for new users.

For more information about our API support guarantees, see here.

Signature

processMessages: (messageCollection: IRuntimeMessageCollection) => void;

Type: (messageCollection: IRuntimeMessageCollection) => void

Method Details

applyStashedOp

Apply changes from an op just as if a local client has made the change, including submitting the op. Used when rehydrating an attached container with pending changes. This prepares the SharedObject for seeing an ACK for the op or resubmitting the op upon reconnection.

This API is provided for existing users, but is not recommended for new users.

For more information about our API support guarantees, see here.

Signature

applyStashedOp(message: any): void;

Parameters

Parameter	Type	Description
message	any

Returns

Should return void.

reSubmit

Called when the runtime asks the client to resubmit an op. This may be because the Container reconnected and this op was not acked. The client can choose to resubmit the same message, submit different / multiple messages or not submit anything at all.

This API is provided for existing users, but is not recommended for new users.

For more information about our API support guarantees, see here.

Signature

reSubmit(message: any, localOpMetadata: unknown, squash?: boolean): void;

Parameters

Parameter	Modifiers	Type	Description
message		any	The original message that was submitted.
localOpMetadata		unknown	The local metadata associated with the original message.
squash	optional	boolean	If true, the DDS should avoid resubmitting any "unnecessary intermediate state" created by this message. This includes any content which this message created but has since been changed or removed by subsequent messages. For example, if this message (call it A) inserts content into a DDS that a subsequent op (call it B) removes, resubmission of this message (call it A') should avoid inserting that content, and resubmission of the subsequent op that removed it (B') would account for the fact that A' never inserted content.

rollback

Revert a local op.

This API is provided for existing users, but is not recommended for new users.

For more information about our API support guarantees, see here.

Signature

rollback?(message: any, localOpMetadata: unknown): void;

Parameters

Parameter	Type	Description
message	any	The original message that was submitted.
localOpMetadata	unknown	The local metadata associated with the original message.

setConnectionState

State change events to indicate changes to the delta connection

This API is provided for existing users, but is not recommended for new users.

For more information about our API support guarantees, see here.

Signature

setConnectionState(connected: boolean): void;

Parameters

Parameter	Type	Description
connected	boolean	true if connected, false otherwise