TSL Child Asset Lookup¶

This stage queries the child node of a specified asset on an asset tree. The functions of this stage include:

Specifying the asset tree by asset tree tags.
Querying the child node of the asset related to the input point.
Querying only 1 level of child node on the asset tree by default.
Supporting the querying of the child node of a specified node on the asset tree.
Attaching queried results in the /attr/tslChildLookup field.
If the queried node has no associated child nodes, a list of length 1 will still be output in /attr/tslChildLookup, encapsulating treeId information.

Configuration¶

The configuration tabs for this stage are General, Basic, Input/Output, and Criteria.

Name	Required?	Description
Name	Yes	The name of the stage.
Description	No	The description of the stage.
Stage Library	Yes	The streaming operator library to which the stage belongs.
Required Fields	No	The fields that the data records must contain. If the specified fields are not included, the record will be filtered out.
Preconditions	No	The conditions that must be satisfied by the data records. Records that do not meet the conditions will be filtered out. For example, `${record:value('/value') > 0}`. For the syntax of EL expressions, see `Expression Language https://docs.streamsets.com/portal/datacollector/latest/help/datacollector/UserGuide/Expression_Language/ExpressionLanguage_overview.html>`__.
On Record Error	Yes	The processing method for error data. Discard: Error data will be discarded and ignored Send to Error: Error messages will be reported Stop Pipeline: The pipeline will be stopped

Name	Required?	Description
Quality Filter	No	Filter the data according to the data quality. Only records that meet the quality conditions will be processed by this stage.

Name	Required?	Description
Input/Output	Yes	The child asset metadata that is attached to each record. Specify the input points that hold the child asset metadata, and the output points that receive the queried results.
Input Point	Yes	Specify the input point that holds the child asset metadata, using the format {modelId}::{pointId}.
Output Point	Yes	Specify the output point that receives the queried results, using the format {modelId}::{pointId}.

Name	Required?	Description
Tree Tag	Yes	Specify the tag of the asset tree, using the format {tag key}::{tag value}.
Attribute	No	Specify whether to query the child asset metadata by the asset attribute keys.
Tag	No	Specify whether to query the child asset metadata by the asset tags.
Extra	No	Specify whether to query the child asset metadata by other information, such as the OU, modelId, modelIdPath, tslInstanceName, tslInstanceDesc, label, timezone, and extraInfo.

The output results of this stage are included in the attr struct. The description of the fields are as follows:

Name	Data Type	Description
/attr/tslChildLookup	List<Child>	The child asset metadata object.
List index	Int	The index of the child asset.
treeId	String	The ID of the asset tree to which the child asset is bound.
assetId	String	The asset ID of the child asset.
attributes	List<attributeId>	The list of child asset attributes.
tags	List<tagId>	The list of child asset tags.
timezone	String	The timezone of the child asset.