July 30, 2023

tFileExist – Docs for ESB 7.x

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tFileExist

Checks if a file exists or not.

tFileExist Standard properties

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

The Standard
tFileExist component belongs to the File family.

The component in this framework is available in all Talend
products.

Basic settings

File name/Stream

Path to the file you want to check if it exists or not.

Warning: Use absolute path (instead of relative path) for
this field to avoid possible errors.

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

EXISTS: the result of whether a specified file exists.
This is a Flow variable and it returns a boolean.

FILENAME: the name of the file processed. This is an
After variable and it returns a string.

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.

Usage

Usage rule

This component can be used as standalone component.

Connections

Outgoing links (from this component to another):

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

Incoming links (from one component to this one):

Row: Iterate.

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

For further information regarding connections, see

Talend Studio

User Guide.

Checking for the presence of a file and creating it if it does not
exist

This scenario describes a simple Job that: checks if a given file exists, displays a
graphical message to confirm that the file does not exist, reads the input data in
another given file and writes it in an output delimited file.

A dialog box appears to confirm that the file does not exists.

Click OK to close the dialog box and continue the Job
execution process. The missing file, file1 in this scenario, got written in a delimited
file in the defined place.

Dropping and linking the components

  1. Drop the following components from the Palette onto the design workspace: tFileExist, tFileInputDelimited, tFileOutputDelimited, and tMsgBox.
  2. Connect tFileExist to tFileInputDelimited using an OnSubjobOk and to tMsgBox using
    a Run If link.

    tFileExist_1.png

  3. Connect tFileInputDelimited to tFileOutputDelimite using a Row
    Main     link.

Configuring the components

  1. In the design workspace, select tFileExist
    and click the Component tab to define its basic
    settings.

    tFileExist_2.png

  2. In the File name field, enter the file path
    or browse to the file you want to check if it exists or not.
  3. In the design workspace, select tFileInputDelimited and click the Component tab to define its basic settings.

    tFileExist_3.png

  4. Browse to the input file you want to read to fill out the File Name field.

    Warning:

    If the path of the file contains some accented characters, you
    will get an error message when executing your Job.

  5. Set the row and field separators in their corresponding fields.
  6. Set the header, footer and number of processed rows as needed. In this
    scenario, there is one header in our table.
  7. Set Schema to Built-in
    and click the Edit schema button to
    define the data to pass on to the tFileOutputDelimited component. Define the data present in the
    file to read, file2 in this scenario.

    For more information about schema types, see
    Talend Studio

    User
    Guide.
    tFileExist_4.png

    The schema in file2 consists of five columns: Num, Ref, Price,
    Quant,     and tax.
  8. In the design workspace, select the tFileOutputDelimited component.
  9. Click the Component tab to define the basic
    settings of tFileOutputDelimited.

    tFileExist_5.png

  10. Set property type to Built-in.
  11. In the File name field, press Ctrl+Space to access the variable list and select the
    global variable FILENAME.
  12. Set the row and field separators in their corresponding fields.
  13. Select the Include Header check box as file2
    in this scenario includes a header.
  14. Set Schema to Built-in and click Sync columns to synchronize the output file schema (file1) with
    the input file schema (file2).

    tFileExist_6.png

  15. In the design workspace, select the tMsgBox
    component.
  16. Click the Component tab to define the basic
    settings of tMsgBox.

    tFileExist_7.png

  17. Click the If link to display its properties
    in the Basic settings view.
  18. In the Condition panel, press Ctrl+Space to access the variable list and select the
    global variable EXISTS. Type an exclamation mark before the variable to negate
    the meaning of the variable.

    tFileExist_8.png

Saving and executing the Job

  1. Press Ctrl+S to save your Job.
  2. Press F6 or click the Run button in the Run tab to
    execute it.

    tFileExist_9.png

Document get from Talend https://help.talend.com
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Docs 7.x
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