tHMap Standard properties
These properties are used to configure tHMap running in the Standard Job framework.
The Standard tHMap component belongs to the Processing family.
This component is available in Talend Data Management Platform, Talend Big Data Platform, Talend Real-Time Big Data Platform, Talend Data Services Platform, Talend MDM Platform and in Talend Data Fabric.
Basic settings
Open Map Editor |
Click the [...] button to open the Structure Generate/Select wizard. You can first select the type of map to create:
Information noteNote: This option is available only if you have installed the
R2023-10 Studio monthly update or a later one delivered by Talend. For more information, check with your administrator.
Then 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. The following lists the options for the output structure:
If Talend Studio detects multiple output connections available, the window displays both output structure options without the support for multiple output connections check boxes. If neither input nor output connection exists, the Structure Selection page is displayed. |
Synchronize map with schema connections |
Select this check box if you want to automatically regenerate
your map's input and output structures after one of the following changes:
If this check box is selected, the map is automatically
synchronized when opened from the component after a change. If not, a dialog appears to
ask whether you want to synchronize.
Information noteNote: For structures with multiple
connections, the map can only be synchronized if the structures have the same form
as the ones generated by the component configuration wizard. For example, flattening
maps with multiple outputs cannot be synchronized automatically.
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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.
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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.
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Advanced settings
Map Variable |
In this field, enter a context variable or a global variable that contains a path to a map. For instance, if you enter context.mymapfile, then mymapfile can point to different map files at runtime. This can be useful in cases where you want to use multiple maps without creating a new Job each time. The value of the variable must be a relative path. For instance, assuming you have a map called mapA in the folder Maps/FolderA, your variable should contain the value "FolderA/mapA.xml". You can write the path to the file with or without the .xml extension. Note that all maps that might be referenced by the variable must be present in the same project. This way, when the Job is built, it will contain all candidate maps and it will be possible to switch from one to another at runtime. For further information on working with context variables, see Using contexts and variables in the Talend Studio User Guide. |
Alternate contextual Map(s) |
From the drop-down list, select a map or several maps that can be referenced by the context variable added in the Map Variable at runtime. The alternate maps selected must have the same map type (standard or DSQL) as the original map. When the Job is built, it contains the selected alternate contextual map or maps. For an example scenario on using Alternate contextual Map(s), see Specifying a map variable and alternate map in tHMap |
Map each row (disable virtual component) |
Select this check box to have tHMap process the input as a single output row. This prevents tHMap from buffering the input rows before delivering them downstream. This can be useful, for example, when you use the tHMap component with tSAPIDocReceiver as the input component and any schema-aware component as the output component, because telling the tSAPIDocReceiver component to keep listening forever would otherwise lead to rows never being delivered. If the tHMap is used with an input component that can remain open to continuously receive inputs, such as the tRestRequest, this option should be selected. It allows the tHMap to directly process the input received. |
Emit empty payload | Select this check box to send an empty row in the
output connection when there is no output data. This can happen if there is
no input or if the entire input is filtered out in the map. If this check
box is cleared, no rows are sent to the output connection. This option is applied only when the Map each row check box is cleared. |
Use old Eclipse runtime (deprecated) |
Select this check box to include the old Eclipse runtime in
your Job.
Information noteNote: This option is available only if you have installed the
R2024-03 Talend Studio monthly update or a later one delivered by Talend. For more information, check with your administrator.
|
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.
To help you diagnose problems with your map, when you test the map in Talend 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
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. MapExecutionStatus: returns an object of the org.talend.transform.runtime.common.MapExecutionStatus class 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 more information about variables, see Using contexts and variables. |
Usage
Usage rule |
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:
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Advanced use case |
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Limitations |
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Usage with Talend Runtime | If you want to deploy a Job or Route containing a data mapping component with Talend Runtime, you first need to install the Talend Data Mapper feature. For more information, see Using Talend Data Mapper with Talend Runtime. |
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For further information about performing transformations using Talend Data Mapper , see this documentation.
- When using representations other than Map, CSV, Avro, XML, and Cobol, running this component with the old Eclipse-based Runtime may create temporary folders, which are not automatically removed after stopping the Runtime. If you frequently run Talend Data Mapper, these files may pile up and eventually lead to a disk full error. When the error occurs, the runtime fails. To avoid this, ensure that you perform periodical cleaning. For more information, see Cleaning up temporary folders and files.