tHMap properties - 6.1

Talend Components Reference Guide

EnrichVersion
6.1
EnrichProdName
Talend Big Data
Talend Big Data Platform
Talend Data Fabric
Talend Data Integration
Talend Data Management Platform
Talend Data Services Platform
Talend ESB
Talend MDM Platform
Talend Open Studio for Big Data
Talend Open Studio for Data Integration
Talend Open Studio for Data Quality
Talend Open Studio for ESB
Talend Open Studio for MDM
Talend Real-Time Big Data Platform
task
Data Governance
Data Quality and Preparation
Design and Development
EnrichPlatform
Talend Studio

Component family

Processing

 

Function

tHMap transforms data from a wide range of sources to a wide range of destinations. If you want to use multiple inputs and/or outputs, you must use Talend Data Mapper I/O functions. For more information, see Talend Data Mapper User Guide.

Purpose

tHMap executes transformations (called maps) between different sources and destinations by harnessing the capabilities of Talend Data Mapper, available in the Mapping perspective.

Basic settings

Open Map Editor

Click the [...] button to open the tHMap Structure Generate/Select wizard where you can either have the hierarchical mapper structure generated automatically based on the schema, or select an existing hierarchical mapper structure. You must do this for both the input and output sides of your Map.

 

Map Path

Specifies the map to be executed.

If the map was automatically created using the wizard described above, this is path is set automatically.

If you want to use an existing map, click the [...] button next to the Map Path field to open a dialog box in which you can select the map you want to use, then click the [...] button next to Open Map Editor to work with the map selected. Note that this map must have previously been created in the Mapping perspective.

Read Input As

Select the radio button which corresponds to how you want the input to be read. Depending on your map, only some of the options may be available.

  • Data Integration columns (default): Use this option if you are working with Talend Data Integration metadata.

  • Single column: Use this option if you are working with Talend Data Mapper metadata.

Write Output As

Select the radio button which corresponds to how you want the output to be written. Depending on your map, only some of the options may be available.

  • Data Integration columns (default): Use this option if you are working with Talend Data Integration metadata.

  • String (single column): Use this option if the data in the output column is to be a String.

  • Byte array (single column): Use this option if the data in the output column is to be a Byte array.

  • InputStream (single column): Use this option if you are working with Talend Data Mapper metadata and the input data is a stream.

  • Document (single column); Use this option if the output column is to be a Document.

Advanced settings

Map Variable

In this field, enter a context variable that you can use to define the absolute path to a map file. This can be useful in cases where you want to use multiple maps without creating a new Job each time.

In the Contexts tab, the value must be an absolute path and the required items (Structures, Maps, and so on) must all be present in the same Talend project. This can be a different project from the current project, but everything must be present in the same project.

For further information on working with context variables, see Talend Studio User Guide.

Log Level

From the drop-down list, select how often you want events to be logged.

  • Infrequent: Logs only events related to startup, shutdown and exceptions.

  • Frequent (default): Logs events related to startup, shutdown and exceptions, and once per map execution.

  • Info: Logs all events at an informational level or higher.

  • All: Logs all events.

  • None: Logs nothing.

 

Exception Threshold

Talend Data Mapper returns an execution status with an severity value which can be OK, Info, Warning, Error or Fatal. By setting the exception threshold, you can specify the severity level at which an exception is thrown, thus enabling downstream components to detect the error in cases other than the default value of Fatal.

From the drop-down list, select the severity level at which an exception may be thrown during the execution of a map.

  • Fatal (default): An exception is thrown when a fatal error occurs.

  • Error: An exception is thrown when an error (or higher) occurs.

  • Warning: An exception is thrown when a warning (or higher) occurs.

Note that, in order to help you diagnose problems with your map, when you test the map in the Studio, any errors that occur which are at warning level or above will be printed in the console window, regardless of the setting of the Exception Threshold.

 tStatCatcher Statistics

Select this check box to gather the Job processing metadata at the Job level as well as at each component level.

Global Variables

ERROR_MESSAGE: the error message generated by the component when an error occurs. This is an After variable and it returns a string. This variable functions only if the Die on error check box is cleared, if the component has this check box.

EXECUTION_STATUS: the pointer to the ExecutionStatus object, which is returned whenever tHMap executes a Talend Data Mapper map. This is an After variable and it returns a string.

EXECUTION_SEVERITY: the Overall Severity numeric value. This is an After variable and it returns an integer.

A Flow variable functions during the execution of a component while an After variable functions after the execution of the component.

To fill up a field or expression with a variable, press Ctrl + Space to access the variable list and choose the variable to use from it.

For further information about variables, see Talend Studio User Guide.

Usage

tHMap is used for Jobs that require complex data mapping from a variety of different sources.

The input and output connections can use Talend Data Mapper metadata, Talend Data Integration metadata, or a combination of the two. Each connection is independent.

When you open the Map Editor for the first time for each connection, it either generates a Talend Data Mapper structure definition based on the schema of the Talend Data Integration component, or allows you to select an existing Talend Data Mapper structure if you are using Talend Data Mapper metadata. It then creates a map with the structure selected or generated.

This component can be used in several ways:

Limitation

n/a

Note

For further information about performing transformations using Talend Data Mapper, see Talend Data Mapper User Guide.