class DynamoGetItem (construct)

Language	Type name
.NET	Amazon.CDK.AWS.StepFunctions.Tasks.DynamoGetItem
Java	software.amazon.awscdk.services.stepfunctions.tasks.DynamoGetItem
Python	aws_cdk.aws_stepfunctions_tasks.DynamoGetItem
TypeScript (source)	@aws-cdk/aws-stepfunctions-tasks » DynamoGetItem

Implements IConstruct, IConstruct, IDependable, IChainable, INextable

A StepFunctions task to call DynamoGetItem.

Example

declare const myTable: dynamodb.Table;
new tasks.DynamoGetItem(this, 'Get Item', {
  key: { messageId: tasks.DynamoAttributeValue.fromString('message-007') },
  table: myTable,
});

Initializer

new DynamoGetItem(scope: Construct, id: string, props: DynamoGetItemProps)

Parameters

• scope Construct
• id string
• props DynamoGetItemProps

Construct Props

Name	Type	Description
key	{ [string]: DynamoAttributeValue }	Primary key of the item to retrieve.
table	ITable	The name of the table containing the requested item.
comment?	string	An optional description for this state.
consistentRead?	boolean	Determines the read consistency model: If set to true, then the operation uses strongly consistent reads;
expressionAttributeNames?	{ [string]: string }	One or more substitution tokens for attribute names in an expression.
heartbeat?	Duration	Timeout for the heartbeat.
inputPath?	string	JSONPath expression to select part of the state to be the input to this state.
integrationPattern?	IntegrationPattern	AWS Step Functions integrates with services directly in the Amazon States Language.
outputPath?	string	JSONPath expression to select select a portion of the state output to pass to the next state.
projectionExpression?	DynamoProjectionExpression[]	An array of DynamoProjectionExpression that identifies one or more attributes to retrieve from the table.
resultPath?	string	JSONPath expression to indicate where to inject the state's output.
resultSelector?	{ [string]: any }	The JSON that will replace the state's raw result and become the effective result before ResultPath is applied.
returnConsumedCapacity?	DynamoConsumedCapacity	Determines the level of detail about provisioned throughput consumption that is returned in the response.
timeout?	Duration	Timeout for the state machine.

---

key

Type: { [string]: DynamoAttributeValue }

Primary key of the item to retrieve.

For the primary key, you must provide all of the attributes. For example, with a simple primary key, you only need to provide a value for the partition key. For a composite primary key, you must provide values for both the partition key and the sort key.

See also: https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_GetItem.html#DDB-GetItem-request-Key

---

table

Type: ITable

The name of the table containing the requested item.

---

comment?

Type: string (optional, default: No comment)

An optional description for this state.

---

consistentRead?

Type: boolean (optional, default: false)

Determines the read consistency model: If set to true, then the operation uses strongly consistent reads;

otherwise, the operation uses eventually consistent reads.

---

expressionAttributeNames?

Type: { [string]: string } (optional, default: No expression attributes)

One or more substitution tokens for attribute names in an expression.

See also: https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_GetItem.html#DDB-GetItem-request-ExpressionAttributeNames

---

heartbeat?

Type: Duration (optional, default: None)

Timeout for the heartbeat.

---

inputPath?

Type: string (optional, default: The entire task input (JSON path '$'))

JSONPath expression to select part of the state to be the input to this state.

May also be the special value JsonPath.DISCARD, which will cause the effective input to be the empty object {}.

---

integrationPattern?

Type: IntegrationPattern (optional, default: IntegrationPattern.REQUEST_RESPONSE for most tasks. IntegrationPattern.RUN_JOB for the following exceptions: BatchSubmitJob, EmrAddStep, EmrCreateCluster, EmrTerminationCluster, and EmrContainersStartJobRun.)

AWS Step Functions integrates with services directly in the Amazon States Language.

You can control these AWS services using service integration patterns

See also: https://docs.aws.amazon.com/step-functions/latest/dg/connect-to-resource.html#connect-wait-token

---

outputPath?

Type: string (optional, default: The entire JSON node determined by the state input, the task result, and resultPath is passed to the next state (JSON path '$'))

JSONPath expression to select select a portion of the state output to pass to the next state.

May also be the special value JsonPath.DISCARD, which will cause the effective output to be the empty object {}.

---

projectionExpression?

Type: DynamoProjectionExpression[] (optional, default: No projection expression)

An array of DynamoProjectionExpression that identifies one or more attributes to retrieve from the table.

These attributes can include scalars, sets, or elements of a JSON document.

See also: https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_GetItem.html#DDB-GetItem-request-ProjectionExpression

---

resultPath?

Type: string (optional, default: Replaces the entire input with the result (JSON path '$'))

JSONPath expression to indicate where to inject the state's output.

May also be the special value JsonPath.DISCARD, which will cause the state's input to become its output.

---

resultSelector?

Type: { [string]: any } (optional, default: None)

The JSON that will replace the state's raw result and become the effective result before ResultPath is applied.

You can use ResultSelector to create a payload with values that are static or selected from the state's raw result.

See also: https://docs.aws.amazon.com/step-functions/latest/dg/input-output-inputpath-params.html#input-output-resultselector

---

returnConsumedCapacity?

Type: DynamoConsumedCapacity (optional, default: DynamoConsumedCapacity.NONE)

Determines the level of detail about provisioned throughput consumption that is returned in the response.

See also: https://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_GetItem.html#DDB-GetItem-request-ReturnConsumedCapacity

---

timeout?

Type: Duration (optional, default: None)

Timeout for the state machine.

Properties

Name	Type	Description
endStates	INextable[]	Continuable states of this Chainable.
id	string	Descriptive identifier for this chainable.
node	ConstructNode	The construct tree node associated with this construct.
startState	State	First state of this Chainable.
stateId	string	Tokenized string that evaluates to the state's ID.
taskMetrics?	TaskMetricsConfig
taskPolicies?	PolicyStatement[]

---

endStates

Type: INextable[]

Continuable states of this Chainable.

---

id

Type: string

Descriptive identifier for this chainable.

---

node

Type: ConstructNode

The construct tree node associated with this construct.

---

startState

Type: State

First state of this Chainable.

---

stateId

Type: string

Tokenized string that evaluates to the state's ID.

---

taskMetrics?

Type: TaskMetricsConfig (optional)

---

taskPolicies?

Type: PolicyStatement[] (optional)

Methods

Name	Description
addCatch(handler, props?)	Add a recovery handler for this state.
addPrefix(x)	Add a prefix to the stateId of this state.
addRetry(props?)	Add retry configuration for this state.
bindToGraph(graph)	Register this state as part of the given graph.
metric(metricName, props?)	Return the given named metric for this Task.
metricFailed(props?)	Metric for the number of times this activity fails.
metricHeartbeatTimedOut(props?)	Metric for the number of times the heartbeat times out for this activity.
metricRunTime(props?)	The interval, in milliseconds, between the time the Task starts and the time it closes.
metricScheduleTime(props?)	The interval, in milliseconds, for which the activity stays in the schedule state.
metricScheduled(props?)	Metric for the number of times this activity is scheduled.
metricStarted(props?)	Metric for the number of times this activity is started.
metricSucceeded(props?)	Metric for the number of times this activity succeeds.
metricTime(props?)	The interval, in milliseconds, between the time the activity is scheduled and the time it closes.
metricTimedOut(props?)	Metric for the number of times this activity times out.
next(next)	Continue normal execution with the given state.
toStateJson()	Return the Amazon States Language object for this state.
toString()	Returns a string representation of this construct.

---

addCatch(handler, props?)

public addCatch(handler: IChainable, props?: CatchProps): TaskStateBase

Parameters

• handler IChainable
• props CatchProps

Returns

• TaskStateBase

Add a recovery handler for this state.

When a particular error occurs, execution will continue at the error handler instead of failing the state machine execution.

---

addPrefix(x)

public addPrefix(x: string): void

Parameters

• x string

Add a prefix to the stateId of this state.

---

addRetry(props?)

public addRetry(props?: RetryProps): TaskStateBase

Parameters

• props RetryProps

Returns

• TaskStateBase

Add retry configuration for this state.

This controls if and how the execution will be retried if a particular error occurs.

---

bindToGraph(graph)

public bindToGraph(graph: StateGraph): void

Parameters

• graph StateGraph

Register this state as part of the given graph.

Don't call this. It will be called automatically when you work with states normally.

---

metric(metricName, props?)

public metric(metricName: string, props?: MetricOptions): Metric

Parameters

• metricName string
• props MetricOptions

Returns

• Metric

Return the given named metric for this Task.

---

metricFailed(props?)

public metricFailed(props?: MetricOptions): Metric

Parameters

• props MetricOptions

Returns

• Metric

Metric for the number of times this activity fails.

---

metricHeartbeatTimedOut(props?)

public metricHeartbeatTimedOut(props?: MetricOptions): Metric

Parameters

• props MetricOptions

Returns

• Metric

Metric for the number of times the heartbeat times out for this activity.

---

metricRunTime(props?)

public metricRunTime(props?: MetricOptions): Metric

Parameters

• props MetricOptions

Returns

• Metric

The interval, in milliseconds, between the time the Task starts and the time it closes.

---

metricScheduleTime(props?)

public metricScheduleTime(props?: MetricOptions): Metric

Parameters

• props MetricOptions

Returns

• Metric

The interval, in milliseconds, for which the activity stays in the schedule state.

---

metricScheduled(props?)

public metricScheduled(props?: MetricOptions): Metric

Parameters

• props MetricOptions

Returns

• Metric

Metric for the number of times this activity is scheduled.

---

metricStarted(props?)

public metricStarted(props?: MetricOptions): Metric

Parameters

• props MetricOptions

Returns

• Metric

Metric for the number of times this activity is started.

---

metricSucceeded(props?)

public metricSucceeded(props?: MetricOptions): Metric

Parameters

• props MetricOptions

Returns

• Metric

Metric for the number of times this activity succeeds.

---

metricTime(props?)

public metricTime(props?: MetricOptions): Metric

Parameters

• props MetricOptions

Returns

• Metric

The interval, in milliseconds, between the time the activity is scheduled and the time it closes.

---

metricTimedOut(props?)

public metricTimedOut(props?: MetricOptions): Metric

Parameters

• props MetricOptions

Returns

• Metric

Metric for the number of times this activity times out.

---

next(next)

public next(next: IChainable): Chain

Parameters

• next IChainable

Returns

• Chain

Continue normal execution with the given state.

---

toStateJson()

public toStateJson(): json

Returns

• json

Return the Amazon States Language object for this state.

---

toString()

public toString(): string

Returns

• string

Returns a string representation of this construct.