EvaluateExpression
Task runners call EvaluateExpression to evaluate a string in the context of the specified object.
For example, a task runner can evaluate SQL queries stored in Amazon S3.
Request Syntax
{
"expression": "string",
"objectId": "string",
"pipelineId": "string"
}Request Parameters
For information about the parameters that are common to all actions, see Common Parameters.
The request accepts the following data in JSON format.
- expression
-
The expression to evaluate.
Type: String
Length Constraints: Minimum length of 0. Maximum length of 20971520.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*Required: Yes
- objectId
-
The ID of the object.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 1024.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\n\t]*Required: Yes
- pipelineId
-
The ID of the pipeline.
Type: String
Length Constraints: Minimum length of 1. Maximum length of 1024.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\n\t]*Required: Yes
Response Syntax
{
"evaluatedExpression": "string"
}Response Elements
If the action is successful, the service sends back an HTTP 200 response.
The following data is returned in JSON format by the service.
- evaluatedExpression
-
The evaluated expression.
Type: String
Length Constraints: Minimum length of 0. Maximum length of 20971520.
Pattern:
[\u0020-\uD7FF\uE000-\uFFFD\uD800\uDC00-\uDBFF\uDFFF\r\n\t]*
Errors
For information about the errors that are common to all actions, see Common Errors.
- InternalServiceError
-
An internal service error occurred.
HTTP Status Code: 500
- InvalidRequestException
-
The request was not valid. Verify that your request was properly formatted, that the signature was generated with the correct credentials, and that you haven't exceeded any of the service limits for your account.
HTTP Status Code: 400
- PipelineDeletedException
-
The specified pipeline has been deleted.
HTTP Status Code: 400
- PipelineNotFoundException
-
The specified pipeline was not found. Verify that you used the correct user and account identifiers.
HTTP Status Code: 400
- TaskNotFoundException
-
The specified task was not found.
HTTP Status Code: 400
Examples
Example
This example illustrates one usage of EvaluateExpression.
Sample Request
POST / HTTP/1.1
Content-Type: application/x-amz-json-1.1
X-Amz-Target: DataPipeline.DescribePipelines
Content-Length: 164
Host: datapipeline.us-east-1.amazonaws.com
X-Amz-Date: Mon, 12 Nov 2012 17:49:52 GMT
Authorization: AuthParams
{"pipelineId": "df-08785951KAKJEXAMPLE",
"objectId": "Schedule",
"expression": "Transform started at #{startDateTime} and finished at #{endDateTime}"}
Sample Response
x-amzn-RequestId: 02870eb7-0736-11e2-af6f-6bc7a6be60d9
Content-Type: application/x-amz-json-1.1
Content-Length: 103
Date: Mon, 12 Nov 2012 17:50:53 GMT
{"evaluatedExpression": "Transform started at 2012-12-12T00:00:00 and finished at 2012-12-21T18:00:00"}
See Also
For more information about using this API in one of the language-specific AWS SDKs, see the following:
