ListDuplicateRemover

Removes all duplicate values from a list attribute. In the resulting list, only distinct values for the list attribute will be present.

Note If the input list has gaps within it, these are eliminated from the output list.

When looking for duplicates, null, missing and empty values are considered equivalent so will be treated as duplicates of each other. The first null, missing or empty string value will be kept.

If there were other attributes in the list “parallel” to the attribute being operated on, these will also be moved in the list to stay in “parallel” with the key attribute. Similarly, if there were other attributes in the list “parallel” to an entry that is a duplicate (so will be removed), those attributes will also be removed.

For matching purposes, a list entry is considered ‘missing’, only if it has a parallel attribute. For example, if list{0}.a exists, then list{0}.b will be considered missing. However if there are no list{0} entries, then list{0}.b will not be considered missing. It rather will be considered to represent a ‘gap’ in the list.

Example

If this feature enters this transformer:

somelist{0}.kind = 'paved'

somelist{1}.kind = 'smooth'

somelist{2}.kind = 'smooth'

somelist{3}.kind = 'rough'

somelist{4}.kind = 'smooth'

somelist{5}.kind = 'smooth'

somelist{6}.kind = 'paved'

somelist{8}.kind = <Null>

and the list name is set to somelist{}.kind, the feature leaving the transformer will have these attributes:

somelist{0}.kind = 'paved'

somelist{1}.kind = 'smooth'

somelist{2}.kind = 'rough'

somelist{3}.kind = <Null>

As another example, if the input feature had these attributes:

somelist{0}.kind = 'paved'

somelist{0}.id = 'A3'

somelist{1}.kind = 'smooth'

somelist{1}.id = 'B7'

somelist{2}.kind = 'smooth'

somelist{2}.id = 'B8'

somelist{3}.kind = 'rough'

somelist{3}.id = 'C9'

somelist{4}.kind = 'smooth'

somelist{4}.id = 'B9'

somelist{5}.kind = 'smooth'

somelist{5}.id = 'B2'

somelist{6}.kind = 'paved'

somelist{6}.id = 'A7'

and the list name is set to somelist{}.kind, the feature leaving the transformer will have these attributes:

somelist{0}.kind = 'paved'

somelist{0}.id = 'A3'

somelist{1}.kind = 'smooth'

somelist{1}.id = 'B7'

somelist{2}.kind = 'rough'

somelist{2}.id = 'C9'

Configuration

Parameters

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.

FME Community

The FME Community is the place for demos, how-tos, articles, FAQs, and more. Get answers to your questions, learn from other users, and suggest, vote, and comment on new features.

Search for all results about the ListDuplicateRemover on the FME Community.