tAdvancedFileOutputXML

Writes an XML file with separated data values according to an XML tree
structure.

tAdvancedFileOutputXML outputs data to an XML type of
file and offers an interface to deal with loop and group by elements if needed.

tAdvancedFileOutputXML Standard properties

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

The Standard
tAdvancedFileOutputXML component belongs to the File and the XML families.

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

Basic settings

Property type	Either Built-in or Repository.
	Built-in: No property data stored centrally.
	Repository: Select the Repository file where Properties are stored. The following fields are pre-filled in using fetched data.
Use Output Stream	Select this check box process the data flow of interest. Once you have selected it, the Output Stream field displays and you can type in the data flow of interest. The data flow to be processed must be added to the flow in order for this component to fetch these data via the corresponding representative variable. This variable could be already pre-defined in your Studio or provided by the context or the components you are using along with this component; otherwise, you could define it manually and use it according to the design of your Job, for example, using tJava or tJavaFlex. In order to avoid the inconvenience of hand writing, you could select the variable of interest from the auto-completion list (Ctrl+Space) to fill the current field on condition that this variable has been properly defined. For further information about how to use a stream, see Reading data from a remote file in streaming mode.
File name	Name or path to the output file and/or the variable to be used. This field becomes unavailable once you have selected the Use Output Stream check box. For further information about how to define and use a variable in a Job, see Talend Studio User Guide.
Configure XML tree	Opens the dedicated interface to help you set the XML mapping. For details 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: The schema will be created and stored locally for this component only. Related topic: see Talend Studio User Guide.
	Repository: The schema already exists and is stored in the Repository, hence can be reused in various projects and job designs. 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 Output component.
Append the source xml file	Select this check box to add the new lines at the end of your source XML file.
Generate compact file	Select this check box to generate a file that does not have any empty space or line separators. All elements then are presented in a unique line and this will reduce considerably file size.
Include DTD or XSL	Select this check box to to add the DOCTYPE declaration, indicating the root element, the access path and the DTD file, or to add the processing instruction, indicating the type of stylesheet used (such as XSL types), along with the access path and file name.

Advanced settings

Split output in several files	If the XML file output is big, you can split the file every certain number of rows.
Trim data	This check box is activated when you are using the dom4j generation mode. Select this check box to trim the leading or trailing whitespace from the value of a XML element.
Create directory only if not exists	This check box is selected by default. It creates a directory to hold the output XML files if required.
Create empty element if needed	This box is selected by default. If no column is associated to an XML node, this option will create an open/close tag in place of the expected tag.
Create attribute even if its value is NULL	Select this check box to generate XML tag attribute for the associated input column whose value is null.
Create attribute even if it is unmapped	Select this check box to generate XML tag attribute for the associated input column that is unmapped.
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 Dom4J as the generation mode.
Add Document type as node	Select this check box to add column(s) of the Document type as node(s) instead of escaped string(s) in the output XML file. This check box appears only when the generation mode is set to Slow and memory-consuming (Dom4j) in the Advanced settings tab.
Advanced separator (for number)	Select this check box to change the expected data separator. Thousands separator: define the thousands separator, between inverted commas Decimal separator: define the decimals separator between inverted commas
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 Once you select Append the source xml file in the Basic settings view, this field disappears because in this situation, your generation mode is set automatically as dom4j.
Encoding	Select the encoding from the list or select Custom and define it manually. This field is compulsory for DB data handling.
Don’t generate empty file	Select the check box to avoid the generation of an empty file.
tStatCatcher Statistics	Select the check box to collect the log data 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 processed. 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 processed. 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	Use this component to write an XML file with data passed on from other components using a Row link.

Defining the XML tree

Double-click on the tAdvancedFileOutputXML
component to open the dedicated interface or click on the three-dot button on the
Basic settings vertical tab of the Component Settings tab.

To the left of the mapping interface, under Schema
List, all of the columns retrieved from the incoming data flow are
listed (only if an input flow is connected to the tAdvancedFileOutputXML component).

To the right of the interface, define the XML structure you want to obtain as
output.

You can easily import the XML structure or create it manually, then map the input
schema columns onto each corresponding element of the XML tree.

Importing the XML tree

The easiest and most common way to fill out the XML tree panel, is to import a well-formed XML file.

Rename the root tag that displays by
default on the XML tree panel, by
clicking on it once.
Right-click on the root tag to display the contextual menu.
On the menu, select Import XML
tree.
Browse to the file to import and click OK.
- You can import an XML tree from files in XML, XSD and
  DTD formats.
- When importing an XML tree structure from an XSD
  file, you can choose an element as the root of your XML tree.
The XML Tree column is hence automatically
filled out with the correct elements.
If you need to add or remove an element or sub-elements, right-click the relevant element of the tree to display the contextual menu.
Select Delete to remove the
selection from the tree or select the relevant option among: Add sub-element, Add
attribute, Add namespace
to enrich the tree.

Creating the XML tree manually

If you don’t have any XML structure defined as yet, you can create it
manually.

Rename the root tag that displays by
default on the XML tree panel, by
clicking on it once.
Right-click on the root tag to display the contextual menu.
On the menu, select Add sub-element to create the first element of the
structure.
If you need to add an attribute or a child element to any element or
remove any element, right-click the left of the corresponding element name to display the contextual
menu.
Right-click to the left of the element name to display the contextual
menu.
On the menu, select the relevant option among: Add sub-element, Add
attribute, Add namespace
or Delete.

Mapping XML data

Once your XML tree is ready, you can map each input column with the relevant XML
tree element or sub-element to fill out the Related
Column.

Click on one of the Schema column
name.
Drag it onto the relevant sub-element to the right.
Release to implement the actual mapping.
If you need to disconnect any mapping on any element of the XML tree, select the element and right-click to the left of the element name to display the contextual menu.
Select Disconnect linker.

Defining the node status

Defining the XML tree and mapping the data is not sufficient. You also need to
define the loop element and if required the group element.

Define a loop element

The loop element allows you to define the iterating object. Generally the Loop element is also the row generator.

To define an element as loop element:

Select the relevant element on the XML tree.
Right-click to the left of the element name to display the contextual
menu.
Select Set as Loop Element.

The Node Status column shows
the newly added status.

There can only be one loop element at a
time.

Define a group element

The group element is optional, it represents a constant element where the groupby operation can be performed. A group element can be defined only if a loop element was defined before.

When using a group element, the rows should sorted, in order to be able to
group by the selected node.

To define an element as group element:

Select the relevant element on the XML tree.
Right-click to the left of the element name to display the contextual
menu.
Select Set as Group Element.

The Node Status column shows the newly added
status and any group status required are automatically defined, if
needed.

Click OK once the mapping is complete to
validate the definition and continue the job configuration where needed.

Creating an XML file using a loop

The following scenario describes the creation of an XML file from a sorted flat file
gathering a video collection.

Configuring the source file

Drop a tFileInputDelimited and a tAdvancedFileOutputXML from the Palette onto the design workspace.
Alternatively, if you configured a description for the input delimited file in
the Metadata area of the Repository, then you can directly drag & drop the metadata
entry onto the editor, to set up automatically the input flow.
Right-click on the input component and drag a row main link towards the
tAdvancedFileOutputXML component to
implement a connection.
Select the tFileInputDelimited component and
display the Component settings tab located in
the tab system at the bottom of the Studio.
Select the Property type, according to
whether you stored the file description in the Repository or not. If you dragged
& dropped the component directly from the Metadata, no changes to the
setting should be needed.

If you didn’t setup the file description in the Repository, then select Built-in and manually fill out the fields displayed on the
Basic settings vertical tab.

The input file contains the following type of columns separated by
semi-colons: id, name,
category, year,
language, director and
cast.

In this simple use case, the Cast field
gathers different values and the id increments when changing movie.
If needed, define the tFileDelimitedInput
schema according to the file structure.
Once you checked that the schema of the input file meets your expectation,
click on OK to validate.

Configuring the XML output and mapping

Then select the tAdvancedFileOutputXML
component and click on the Component settings
tab to configure the basic settings as well as the mapping. Note that a
double-click on the component will open directly the mapping interface.
In the File Name field, browse to the file to
be written if it exists or type in the path and file name that needs to be
created for the output.

By default, the schema (file description) is automatically propagated from the
input flow. But you can edit it if you need.
Then click on the three-dot button or double-click on the tAdvancedFileOutputXML component on the design
workspace to open the dedicated mapping editor.

To the left of the interface, are listed the columns from the input file
description.
To the right of the interface, set the XML tree panel to reflect the expected
XML structure output.

You can create the structure node by node. For more information about the
manual creation of an XML tree, see Defining the XML tree.

In this example, an XML template is used to populate the XML tree
automatically.
Right-click on the root tag displaying by
default and select Import XML tree at the end
of the contextual menu options.
Browse to the XML file to be imported and click OK
to validate the import operation.

Note:

You can import an XML tree from files in XML, XSD and DTD formats.
Then drag & drop each column name from the Schema
List to the matching (or relevant) XML
tree elements as described in Mapping XML data.

The mapping is shown as blue links between the left and right panels.

Finally, define the node status where the loop should take place. In this use
case, the Cast being the changing element on which the
iteration should operate, this element will be the loop element.

Right-click on the Cast element on the XML tree, and select Set as loop element.
To group by movie, this use case needs also a group element to be
defined.

Right-click on the Movie parent node of the XML tree, and select Set as group element.

The newly defined node status show on the corresponding element lines.
Click OK to validate the
configuration.
Press F6 to execute the Job.

The output XML file shows the structure as defined.

Document get from Talend https://help.talend.com

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Docs 7.x

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tAdvancedFileOutputXML – Docs for ESB 7.x

tAdvancedFileOutputXML