# 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 Talend Data Fabric. ## 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. The following
lists the options for the output structure:

Generate hierarchical mapper structure based on the schema option: When you connect multiple output connections to the tHMap, the page displays a confirmation message that informs you that the mapper structures are generated based on the output connections.
Select an existing hierarchical mapper structure option: You can connect multiple outputs that are payload-based connections to the tHMap. If there is a single payload-type connection, you can select the Allow support for multiple output connections check box. The generated output map inherits from the existing payload 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. | | --- | --- | | 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.

Information noteNote: If you have selected Document (single column) in the Job you created in versions 6.5 or below of Talend Studio and would like to import the same Job to the latest versions 7.0 or onwards, ensure that you have updated the output representation of the map to XML prior to executing the Job. Versions 7.0 or onwards only accept the Document output type with XML representation.

| ## Advanced settings | Map Variable | In this field, enter a context 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.

In the Contexts
tab, the value must be an relative path. For instance, assuming you have
a map called *mapA* in the folder *Maps/FolderA*, your context 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
context 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 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. 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](https://help.qlik.com/talend/en-US/components/7.3/data-mapping/specifying-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.

Information noteNote: This option is available only when you have
installed the R2021-05 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.

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 | 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 further information about variables, see *Talend Studio*
*User Guide*. | | --- | --- | ## 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:

You can work with a Talend Data Mapper map and structures based on Talend Data Mapper metadata. In this case, the components (for instance, tFileInputRaw and tFileOutputRaw) pass the data in a single column in a single row.

For an example of this usage, see Using metadata.
You can work with Talend Data Integration metadata. In this case, you connect an input and output component to tHMap then open the Map Editor without specifying a map path.

For an example of this usage, see Using metadata.
You can work with a combination of Talend Data Mapper metadata and Talend Data Integration metadata.

For an example of this usage, see Transforming from a Data Integration schema to a complex content schema.
You can work with raw file inputs and schema-based input connections as inputs to tHMap.
For examples of this usage, see Generating the Output Using tHMap with Multiple Schema Inputs and Generating the Output using tHMap with Multiple Payload Inputs.
You can work with database tables created in Talend Studio and connect these tables as inputs to tHMap. If you have Jobs that use the deprecated DatabaseLookup functionality, see Migrating from DatabaseLookup to tHMap for the steps on how to migrate to tHMap.
You have the option to connect tHMap to multiple database output connections. To migrate previously created Jobs using IO Database functions, see Migrating IO Database functions to tHMap Multi-Output Database Connections.
You can connect tHMap to multiple output connections using raw file, schema-based connections, and payload-based connections.
Handling errors shows how to handle error conditions using the tHMap component.
For a thMap with a single connection, the Wrap Structure option (Allow tHMap to support multiple inputs/outputs) is, by default, unchecked for these options: Generate from Schema (schema-based) and Select From Existing Structure (payload-type).

| | --- | --- | | Advanced use case |

For the output Structure of the thMap, you can also use the WriteURL function in Talend Data Mapper . In case the output Structure of the tHMap includes both a connection to a Talend Data Integration metadata or component and a WriteURL function, the WriteURL value takes precedence. Talend Data Integration metadata or component does not receive any data from tHMap.
Using tHMap, you can test the generated Talend Data Mapper Map in Test Run mode.
To use the feature, ensure that you have a compatible input document of CSV format with these properties:
- the default delimiter is the (,) comma;
- the system default line separator is used as the newline;
- there exists no header row in the input file;
- there will be no header row in the output file.
Specify your input document in Show Document > Select Sample Input Document > Select Resource/Import Document.

To execute the transformation, click Test Run. After execution, your generated output document is in CSV format, which you can save by clicking Save to File. To configure this feature, see Test preferences in the Talend Data Mapper User Guide.

Information noteTip: If you have multiple inputs and outputs in your Map, specify an input document for each row or each ReadURL map element. To execute, use the Test Run to External Output option and specify a file URL for each WriteURL in the output structure of the Map.

| | Limitations |

If you created a tHMap with multiple input or output connections, you can only add new schema-based input or output connections.
When you add a new connection with a single column, you cannot associate it with a payload structure. The Map Regeneration mechanism only generates a single-element record for the new connection.
If you rename a payload-type connection, regenerate the corresponding map and its structure by double-clicking on the tHMap before closing the Job editor. The renamed record structure then contains the payload structure.
If in the event that you closed the Job prior to regenerating a renamed payload-type connection, the system treats the connection as a schema-type connection. The payload structure does not get associated with the new name.
A Job containing a tHMap cannot be deployed as an OSGi bundle with the old Eclipse-based runtime.

| | 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](https://help.qlik.com/talend/r/en-US/7.3/data-mapper-user-guide/using-talend-data-mapper-with-talend-runtime). | Information noteNote: * For further information about performing transformations using Talend Data Mapper , see Talend Data Mapper User Guide. * 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](https://help.qlik.com/talend/r/en-US/7.3/data-mapper-user-guide/cleaning-up-temporary-folders-and-files).