XMLUpdater

This transformer modifies XML documents by performing one or more of the following actions:

Replace an XML element or attribute.
Replace the contents of an element or attribute.
Delete an XML element or attribute.
Delete the contents of an XML element or attribute.
Rename an element or attribute
Insert a new element or attribute.

For each document update, an XML path expression is used to identify the location of the items to be modified. Note that the path may refer to more than one item. If this is the case, all the items will be modified.

For modifications that replace existing items or insert new items, two parameters are given which specify the value to be added to the document. This value may be given as a simple text value, or it may be an XQuery expression.

The Update features provide the attribute values used in the document update operations. The Document feature is only used to supply the XML document which is to be updated.

For each feature that enters the Update port, all update operations listed in the transformer will be applied to each feature that entered the transformer through the Document port. Therefore, no changes will be made to the XML document if no features enter the transformer through the Update port.

Note that if the document is entered directly into the transformer parameters, it may be processed in two different ways:

If no Document features are given to the transformer, a new feature will be created to store the document. Each of the updates will be applied to the document, and it will then be output through the Document port.
If Document features are given to the transformer, each of the updates will be applied to the document, then it will be copied to each Document input feature before these features are output from the transformer.

Configuration

Input Ports

Output Ports

Parameters

Group Processing

Group Update Features By

This parameter is used to specify which update features will modify a document. When this parameter is set to a list of attributes, Document features will only be modified by Update features that share the same values for these attributes. The document will be modified by all of the update features with the same attribute values. Note that a document will not be updated if no Update features with the same values for the “group by” attributes are provided to the transformer.

Complete Groups

Select the point in processing at which groups are processed:

When All Features Received	This is the default behavior. Processing will only occur in this transformer once all input is present.
When Group Changes (Advanced)	This transformer will process input groups in order. Changes of the value of the Group By parameter on the input stream will trigger processing on the currently accumulating group. This may improve overall speed (particularly with multiple, equally-sized groups), but could cause undesired behavior if input groups are not truly ordered.

XML Document

XML Input	This parameter is used to specify the type of XML document which is to be modified. The XML may come from the input features (Parameter Value: Text or Attribute), or it may come from an external file. (Parameter Value: XML File)
XML Text	When the XML Input parameter is set to Text or Attribute, this parameter is used to specify the XML file. The parameter may be set to an attribute value, or the XML document may be entered into the parameter directly.
XML File	When the XML Input parameter is set to XML File, this parameter is used to specify the location of the file. The file path may be entered directly into the parameter, or the path may come from an attribute value.

Updates

Update Type

This parameter specifies the type of modification to apply to the XML document. The possible updates are:

Update Type	Description
Replace	Each of the items referred to by the XML Path parameter will be replaced with the value given in the Value parameter.
Replace contents	Each of the items referred to by the XML Path parameter will have their content replaced with the value given in the Value parameter.
Replace with contents	Each of the items referred to by the XML Path parameter will be replaced with their contents. That is, the node will be removed but the node's children and text content will remain.
Delete	Each of the items referred to by the XML Path parameter will be removed from the document.
Delete contents	The contents of the items referred to by the XML Path parameter will be removed from the document. If the path refers to an element, all child elements and text content of referred elements will be deleted, while attributes will be unmodified. If the path refers to an attribute, its value will be removed.
Rename	The element or attribute referred to by the path will be renamed. Note that if the Value Type parameter is XML/XQuery, then the XQuery expression in the Value parameter should evaluate to a string or a QName object.
Insert as first child	The value given in the Value parameter will be inserted as the first child of each element referred to by the XML Path parameter.
Insert as last child	The value given in the Value parameter will be inserted as the last child of each element referred to by the XML Path parameter.
Insert as previous sibling	The value given in the Value parameter will be inserted into the parent element of each item referred to by the XML Path parameter. It will appear immediately before the referred item.
Insert as next sibling	The value given in the Value parameter will be inserted into the parent element of each item referred to by the XML Path parameter. It will appear immediately after the referred item.

XML Path

This parameter specifies the location of the XML nodes which are to be updated. Any XQuery expression may be used here, as long as it returns nodes contained in the input document. If the path expression evaluates to more than one item, they will all be modified.

The simplest parameter value is a path expression, for example:

/data/record/name

With this path expression, the transformer will modify every <name> element which is contained in a <record> element which is contained in a root <data> element. A predicate may be used to narrow down this selection. For example, to modify the <name> element in the first <record> only, the following path could be used:

/data/record[1]/name

Similarly, a predicate may also be used to narrow the selection based on an attribute value:

/data/record[@id = "A-123"]/name

Notably, since this is an XQuery expression, the FME XQuery functions may be used.

Note The feature-level XQuery functions (such as fme:get-attribute) used in the Path parameter will apply to the Update feature being processed, not the Document feature that is being updated

/data/record[@id=fme:get-attribute("record_id")]/name.

The transformer will modify only those <name> elements contained in a <record> element whose id attribute is equal to the record_id feature attribute. This also works with list attributes. The following path expression will modify all <name> elements contained in a <record> element whose id attribute is contained in the _ids feature attribute.

/data/record[@id=fme:get-list-attribute("_ids{}")]/name

The path expression must be namespace correct. That is, the prefixes (or lack of prefixes) must match exactly the prefixes used in the input XML document. A wildcard (*) may be used as a namespace prefix. The path /*:data will match a <data> element in any namespace, including the default namespace and empty namespace. Similarly, a wildcard may be used for an element name. The path gml:* will match any element in the namespace bound to the gml prefix. To combine these approaches, the *:* syntax may not be used. Rather, a single * character should be used.

Value Type

This parameter is used to indicate how the value of the Value parameter should be interpreted. The effects of the different values of this parameter are explained in the description of the Value parameter. In general, this parameter should be set to Plain Text if the transformer is intended to insert text content into the document, while it should be set to XML/XQuery if the transformer is intended to insert XML elements into the document.

Value

This parameter is used to specify the new values that should be inserted into the document. If the Value Type parameter is set to Plain Text, the contents of this parameter will be encoded for safe use in an XML document. That is, < characters will be encoded as <, > characters will be encoded as > and so on.

If the Value Type parameter is set to XML/XQuery, the contents of this parameter will be interpreted as an XQuery expression. This allows the insertion of XML elements into the document. Also, this allows the use of the FME XQuery functions. For example, an XML Template (for example, from the XMLTemplater transformer) could be entered as the parameter value. It would then be evaluated before being inserted into the document.

Here are some examples of using the XML/XQuery mode of the XMLUpdater:

Given the example root document

Copy

<data>
 <record>
  <id>A123</id>
 </record>
</data>

To insert a <record> fragment into the document, the following can be used in the text editor or as an attribute.

Copy

<record>
 <id>B123</id>
</record>

This can also be done using FME XQuery functions:

Copy

<record>
 <id>{fme:get-attribute("record_id")}</id>
</record>

Note Any FME XQuery functions used in the new value will access the Update feature, not the Document feature.

Editing Transformer Parameters

Transformer parameters can be set by directly entering values, using expressions, or referencing other elements in the workspace such as attribute values or user parameters. Various editors and context menus are available to assist. To see what is available, click beside the applicable parameter.

How to Set Parameter Values

Defining Values

There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters.

Using the Text Editor

The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.

Text Editor

Using the Arithmetic Editor

The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.

Arithmetic Editor

Conditional Values

Set values depending on one or more test conditions that either pass or fail.

Parameter Condition Definition Dialog

Content

Expressions and strings can include a number of functions, characters, parameters, and more.

When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.

Content Types

String Functions	These functions manipulate and format strings.
Special Characters	A set of control characters is available in the Text Editor.
Math Functions	Math functions are available in both editors.
Date/Time Functions	Date and time functions are available in the Text Editor.
Math Operators	These operators are available in the Arithmetic Editor.
FME Feature Functions	These return primarily feature-specific values.
FME Parameters	FME and workspace-specific parameters may be used.
Creating and Modifying User Parameters	Create your own editable parameters.

Dialog Options - Tables

Table Tools

Transformers with table-style parameters have additional tools for populating and manipulating values.

Row Reordering

Enabled once you have clicked on a row item. Choices include:

Add a row
Remove a row
Move current row up one
Move current row down one
Move current row to top
Move current row to bottom

Cut, Copy, and Paste

Enabled once you have clicked on a row item. Choices include:

Cut a row - delete and copy to clipboard
Copy a row to the clipboard
Paste a row from the clipboard

Cut, copy, and paste may be used within a transformer, or between transformers.

Filter

Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output.

Import

Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers.

Reset/Refresh

Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers.

Note: Not all tools are available in all transformers.

For more information, see Transformer Parameter Menu Options.

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Validate Attribute Names	This parameter specifies whether or not FME Workbench should try to validate the attribute names which are passed to any XQuery functions used in the XML Path column and the Value column.
Write XML Header	This parameter specifies whether the updated XML document should start with an XML header declaration. By default, the output will contain an XML header. Omitting the header can be useful when the output is to be concatenated with other values into a larger XML document.