tFileOutputARFF – Docs for ESB 5.x

Component family

File/Output

Function

tFileOutputARFF outputs data to
an ARFF file.

Purpose

This component writes an ARFF file that holds data organized
according to the defined schema.

Basic settings

Property type

Either Built-in or Repository.

Since version 5.6, both the Built-In mode and the Repository mode are
available in any of the Talend solutions.

Built-in: No property data stored
centrally.

Repository: Select the repository
file where the properties are stored. The fields that follow are
completed automatically using the data retrieved.

Click this icon to open a connection wizard and store the Excel
file connection parameters you set in the component Basic settings view.

For more information about setting up and storing file connection
parameters, see Talend Studio User
Guide.

File name

Name or path to the output file and/or the variable to be used.

For further information about how to define and use a variable in
a Job, see Talend Studio
User Guide.

Attribute Define

Displays the schema you defined in the [Edit
schema] dialog box.

Column: Name of the
column.

Type: Data type.

Pattern: Enter the data model
(pattern), if necessary.

Relation

Enter the name of the relation.

Append

Select this check box to add the new rows at the end of the
file.

Schema and Edit
Schema

A schema is a row description, it defines the number of fields to be processed and
passed on to the next component. The schema is either Built-in or stored remotely in the
Repository.

Since version 5.6, both the Built-In mode and the Repository mode are
available in any of the Talend solutions.

Click Edit schema to make changes to the schema. If the
current schema is of the Repository type, three options are
available:

Built-in: You can create the
schema and store it locally for this component. Related topic: see
Talend Studio User
Guide.

Repository: You have already
created and stored the schema in the Repository. You can reuse it in
various projects and Job flowcharts. Related topic: see
Talend Studio User
Guide.

Create directory if not exists

This check box is selected by default. It creates a directory to
hold the output table if it does not exist.

Advanced settings

Don’t generate empty file

Select this check box if you do not want to generate empty
files.

tStatCatcher Statistics

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

Dynamic settings

Click the [+] button to add a row in the table and fill the
Code field with a context variable to choose your HDFS
connection dynamically from multiple connections planned in your Job. This feature is useful
when you need to access files in different HDFS systems or different distributions,
especially when you are working in an environment where you cannot change your Job settings,
for example, when your Job has to be deployed and executed independent of Talend Studio.

The Dynamic settings table is available only when the
Use an existing connection check box is selected in the
Basic settings view. Once a dynamic parameter is
defined, the Component List box in the Basic settings view becomes unusable.

For more information on Dynamic settings and context
variables, see Talend Studio User Guide.

Global Variables

NB_LINE: the number of rows read by an input component or
transferred to an output component. This is an After variable and it returns an
integer.

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.

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.

Connections

Outgoing links (from this component to another):

Row: Main.

Trigger: On Subjob Ok; On Subjob
Error; Run if.

Incoming links (from one component to this one):

Row: Main; Reject;
Iterate.

Trigger: On Subjob Ok; On Subjob
Error; Run if; On Component Ok; On Component Error; Synchronize;
Parallelize.

For further information regarding connections, see
Talend Studio User
Guide.

Usage

Use this component along with a Row link to collect data from another component and
to re-write the data to an ARFF file.

Log4j

The activity of this component can be logged using the log4j feature. For more information on this feature, see Talend Studio User
Guide.

For more information on the log4j logging levels, see the Apache documentation at http://logging.apache.org/log4j/1.2/apidocs/org/apache/log4j/Level.html.

Limitation

Due to license incompatibility, one or more JARs required to use this component are not
provided. You can install the missing JARs for this particular component by clicking the
Install button on the Component tab view. You can also find out and add all missing JARs easily on
the Modules tab in the Integration perspective
of your studio. For details, see https://help.talend.com/display/KB/How+to+install+external+modules+in+the+Talend+products
or the section describing how to configure the Studio in the Talend Installation and Upgrade
Guide.