NullAttributeMapper

Map

Whether to map All Attributes or Selected Attributes. All Attributes will operate on all attributes present on the feature, including format attributes. Please note that All Attributes will not operate on missing attributes. To map missing attributes, users must choose Selected Attributes.

Selected Attributes

Users must explicitly specify attributes to be mapped. Please note that checking ‘Select all’ within the ‘Select Selected Attributes Items’ dialog is not generally the same as choosing All Attributes for the Map parameter. For example, many existing attributes on the feature may not be exposed. In this case, All Attributes will process these unexposed attributes, while Selected Attributes will not be able to.

If Attribute Value Is	For the specified attributes, check the value of the attribute in the input feature and if it is one of the specified values, take the action specified by the Map To parameter. Values that can be matched are: Empty – The attribute exists and has an empty string as its value. Null – The attribute exists and has a value of null. Missing (Selected Attributes Only) – The attribute does not exist.
Or If Attribute Value Is	If this parameter has a value and the attribute value matches the specified value, the Map To action will be applied.
Or If Attribute Value Contains Regex	If this parameter has a value and the attribute value contains the specified regular expression, then the Map To action will be applied. The containment check is case-sensitive. Advanced regular expression (AREs) are supported. If the attribute value matches the specified regular expression, then the Map To action will be applied. This table lists the special characters: Special Character Description | separates "branches" (or choices) *  a sequence of 0 or more matches of what precedes it + a sequence of 1 or more matches of what precedes it ? a sequence of 0 or 1 matches of what precedes it . matches any single character ^ matches the start of the value $ matches the end of the value [ ] enclose a set of character choices ( ) enclose a "subexpression" a any character can be listed to be matched
Map To	This parameter specifies how to map matching attributes. Possible actions are: Null – This will cause the attribute to be set to a null value. Missing – The attribute will be deleted. Empty String – The attribute value will be set to an empty string (which has length 0). New Value – The attribute will be set to the value specified by the New Value parameter.
New Value	This parameter specifies the value to set an attribute to if New Value is specified as the Map To action.

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.

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.