July 30, 2023

tWriteXMLField – Docs for ESB 7.x

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tWriteXMLField

Reads an input XML file and extracts the structure to insert it in defined fields
of the output XML file.

tWriteXMLField Standard properties

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

The Standard
tWriteXMLField component belongs to the XML family.

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

Basic settings

Output Column

Select the destination field in the output component where you
want to write the XML structure.

Configure XML Tree

Opens the interface that supports the creation of the XML
structure you want to write in a field. For more information about
the interface, see Defining the XML tree.

Schema and Edit
Schema

A schema is a row description, it defines the number of fields that will be processed
and passed on to the next component. The schema is either built-in
or remote 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.

 

Built-in: You create the schema
and store it locally for this component only. Related topic: see

Talend Studio User
Guide.

 

Repository: You already created
the schema and stored it in the Repository, hence can be reused in
various projects and job flowcharts. Related topic: see

Talend Studio User
Guide.

Sync columns

Click to synchronize the output file schema with the input file
schema. The Sync function only displays once the Row connection is
linked with the input component.

Group by

Define the aggregation set, the columns you want to use to regroup
the data.

Advanced settings

Remove the XML declaration

Select this check box if you do not want to include the XML
header.

Create empty element if needed

This check box is selected by default. If the Related Column in the XML tree editor has
null values, or if no column is associated with the XML node, this
option creates an open/close tag in the expected place.

Expand Empty Element if needed(for dom4j)

Select this option to allow a null element to appear in the form
of tag pair, e.g. <element></element>. Otherwise, such an
element appears as a solo tag, e.g. <element/>. For more
information about XML tags, see http://www.tizag.com/xmlTutorial/xmltag.php.

Note: To use this option, you must select the Dom4J generation mode.
Available when Create empty element if
needed is selected.

Create associated XSD file

If one of the XML elements is defined as a Namespace element, this
option will create the corresponding XSD file.

Note: To use this option, you must select the Dom4J generation mode.

Advanced separator (for number)

Select this check box if you want to modify the separators used by
default for numbers.

Thousands separator: enter between
brackets the separators to use for thousands.

Decimal separator: enter between
brackets the separators to use for decimals.

Generation mode

Select the appropriate generation mode according to your memory
availability. The available modes are:

  • Slow and memory-consuming
    (Dom4j)

    Note: This option allows you to use dom4j to process the XML
    files of high complexity.
  • Fast with low memory
    consumption

Encoding

Select the encoding type in the list or select Custom and define it manually. This field
is compulsory when working with databases.

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.

Usage

Usage rule

This component can be used as intermediate step in a data
flow.

Extracting the structure of an XML file and inserting it into the fields of
a database table

This three-component scenario allows to read an XML file, extract the XML structure,
and finally outputs the structure to the fields of a database table.

Procedure

  1. Drop the following components from the Palette onto the design workspace: tFileInputXml, tWriteXMLField,
    and tMysqlOutput.

    Connect the three components using Main
    links.
    tWriteXMLField_1.png

  2. Double-click tFileInputXml to open its
    Basic settings view and define its
    properties.

    tWriteXMLField_2.png

  3. If you have already stored the input schema in the Repository tree view, select Repository first from the Property
    Type     list and then from the Schema list to display the Repository
    Content     dialog box where you can select the relevant metadata.

    For more information about storing schema metadata in
    the Repository tree view, see
    Talend Studio User
    Guide    .
  4. If you have not stored the input schema locally, select Built-in in the Property Type
    and Schema fields and fill in the fields that
    follow manually. For more information about tFileInputXML properties, see tFileInputXML.

    If you have selected Built-in, click the
    three-dot button next to the Edit schema field
    to open a dialog box where you can manually define the structure of your
    file.
  5. In the Look Xpath query field, enter the node
    of the structure where the loop is based. In this example, the loop is based on
    the customer node. Column
    in the Mapping table will be automatically
    populated with the defined file content.

    In the Xpath query column, enter between
    inverted commas the node of the XML file that holds the data corresponding to
    each of the Column fields.
  6. In the design workspace, click tWriteXMLField
    and then in the Component view,
    click Basic settings to open the relevant view
    where you can define the component properties.

    tWriteXMLField_3.png

  7. Click the three-dot button next to the Edit
    schema     field to open a dialog box where you can add a line by
    clicking the plus button.

    tWriteXMLField_4.png

  8. Click in the line and enter the name of the output column where you want to
    write the XML content, CustomerDetails in this example.

    Define the type and length in the corresponding fields,
    String and 255in this example.
    Click Ok to validate your output schema and
    close the dialog box.
    In the Basic settings view and from the
    Output Column list, select the column you
    already defined where you want to write the XML content.
  9. Click the three-dot button next to Configure Xml
    Tree     to open the interface that helps to create the XML
    structure.

    tWriteXMLField_5.png

  10. In the Link Target area, click
    rootTag and rename it as
    CustomerDetails.

    In the Linker source area, drop
    CustomerName and CustomerAddress
    to CustomerDetails. A dialog box displays asking what type
    of operation you want to do.
    Select Create as sub-element of target node
    to create a sub-element of the CustomerDetails node.
    Right-click CustomerName and select from the contextual
    menu Set As Loop Element.
    Click OK to validate the XML structure you
    defined.
  11. Double-click tMysqlOutput to open its
    Basic settings view and define its
    properties.

    tWriteXMLField_6.png

  12. If you have already stored the schema in the DB
    Connection     node in the Repository tree view, select Repository from the Schema list
    to display the Repository Content dialog box
    where you can select the relevant metadata.

    For more information about storing schema metadata in
    the Repository tree view, see
    Talend Studio User
    Guide    .
    If you have not stored the schema locally, select Built-in in the Property Type
    and Schema fields and enter the database
    connection and data structure information manually. For more information about
    tMysqlOutput properties, see tMysqlOutput.
    In the Table field, enter the name of the
    database table to be created, where you want to write the extracted XML
    data.
    From the Action on table list, select
    Create table to create the defined
    table.
    From the Action on data list, select Insert
    to write the data.
    Click Sync columns to retrieve the schema
    from the preceding component. You can click the three-dot button next to
    Edit schema to view the schema.
  13. Save your Job and click F6 to execute it.
tWriteXMLField_7.png

tWriteXMLField fills every field of the
CustomerDetails column with the XML structure of the input
file: the XML processing instruction <?xml version=""1.0""
encoding=""ISO-8859-15""?>, the first node that separates each client
<CustomerDetails> and finally customer information
<CustomerAddress> and <CustomerName>.

Document get from Talend https://help.talend.com
Thank you for watching.
Docs 7.x
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