tReplace

Cleanses all files before further processing.

Carries out a Search &
Replace operation in the input columns defined.

Depending on the Talend solution you
are using, this component can be used in one, some or all of the following Job
frameworks:

Standard: see tReplace Standard properties.

The component in this framework is generally available.
MapReduce: see tReplace MapReduce properties.

The component in this framework is available only if you have subscribed to one
of the
Talend
solutions with Big Data.
Spark Batch:
see tReplace properties for Apache Spark Batch.

The component in this framework is available only if you have subscribed to one
of the
Talend
solutions with Big Data.
Spark Streaming:
see tReplace properties for Apache Spark Streaming.

The component in this framework is available only if you have subscribed to Talend Real-time Big Data Platform or Talend Data
Fabric.

tReplace Standard properties

These properties are used to configure tReplace running in the Standard Job framework.

The Standard
tReplace component belongs to the Processing family.

The component in this framework is generally available.

Basic settings

Schema and Edit Schema	A schema is a row description. It defines the number of fields (columns) to be processed and passed on to the next component. The schema is either Built-In or stored remotely in the Repository. Click Edit schema to make changes to the schema. If the current schema is of the Repository type, three options are available: View schema: choose this option to view the schema only. Change to built-in property: choose this option to change the schema to Built-in for local changes. Update repository connection: choose this option to change the schema stored in the repository and decide whether to propagate the changes to all the Jobs upon completion. If you just want to propagate the changes to the current Job, you can select No upon completion and choose this schema metadata again in the [Repository Content] window. Two read-only columns, Value and Match are added to the output schema automatically.
	Built-In: You create and store the schema locally for this component only. Related topic: see Talend Studio User Guide.
	Repository: You have already created the schema and stored it in the Repository. You can reuse it in various projects and Job designs. Related topic: see Talend Studio User Guide.
Simple Mode Search / Replace	Click the button to add as many conditions as needed. The conditions are performed one after the other for each row. Input column: Select the column of the schema the search & replace is to be operated on Search: Type in the value to search in the input column Replace with: Type in the substitution value. Whole word: Select this check box if the searched value is to be considered as whole. Case sensitive: Select this check box to care about the case. Note that you cannot use regular expression in these columns.
Use advanced mode	Select this check box when the operation you want to perform cannot be carried out through the simple mode. In the text field, type in the regular expression as required.

Advanced settings

tStatCatcher Statistics	Select this check box to gather the job processing metadata at a 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. 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. 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.

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.

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.

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	This component is not startable as it requires an input flow. And it requires an output component.

Scenario 1: Multiple replacements and column filtering

This following Job searches and replaces various typos and defects in a csv file then
operates a column filtering before producing a new csv file with the final
output.

Drop the following components from the Palette onto the design workspace: tFileInputDelimited, tReplace,
tFilterColumn and tFileOutputDelimited.
Connect the components using Main Row
connections via a right-click each component.
Select the tFileInputDelimited component and
set the input flow parameters.

The File is a simple csv file stored
locally. The Row Separator is a carriage return
and the Field Separator is a semi-colon. In the
Header is the name of the column, and no
Footer nor Limit are to be set.
The file contains characters such as: *t, . or
Nikson which we want to turn into Nixon, and
streat, which we want to turn into Street.

The schema for this file is built in also and made of four columns of various
types (string or int).
Now select the tReplace component to set the
search & replace parameters.

The schema can be synchronized with the incoming flow.
Select the Simple mode check box as the
search parameters can be easily set without requiring the use of regexp.
Click the plus sign to add some lines to the parameters table.
On the first parameter line, select Amount as InputColumn. Type “.” in the Search field, and
“,” in the Replace
field.
On the second parameter line, select Street as InputColumn. Type “streat” in the Search field,
and “Street” in the Replace field.
On the third parameter line, select again Amount as
InputColumn. Type “$” in the Search field, and
“£” in the Replace field.
On the fourth paramater line, select Name
as InputColumn. Type “Nikson” in the Search field,
and “Nixon” in the Replace field.
On the fifth parameter line, select Firstname as
InputColumn. Type “*t” in the Search field, and
replace them with nothing between double quotes.
The advanced mode isn’t used in this scenario.
Select the next component in the Job, tFilterColumn.

The tFilterColumn component holds a schema
editor allowing to build the output schema based on the column names of the
input schema. In this use case, add one new column named empty_field and change the order of the input schema columns to
obtain a schema as follows: empty_field, Firstname, Name, Street,
Amount.
Click OK to validate.

Set the tFileOutputDelimited properties
manually.
The schema is built-in for this scenario, and comes from the preceding
component in the Job.
Save the Job and press F6 to execute
it.

The first column is empty, the rest of the columns have been cleaned up from the
parasitical characters, and Nikson was replaced with
Nixon. The street column was moved and the
decimal delimiter has been changed from a dot to a comma, along with the currency
sign.