ListConcatenator

Concatenates all the values of a list into a single attribute.

Example

If this feature enters the ListConcatenator:

• somelist{0}.length        = 7.3
• somelist{0}.kind             = ’paved’
• somelist{1}.length       = 8.4
• somelist{1}.kind             = ’smooth’
• somelist{1}.lanes            = 2
• somelist{2}.length        = 1.1
• somelist{2}.kind             = ’rough’

and a concatenation of somelist{}.kind with a backslash (\\) separator is requested, then the resulting attribute will contain: paved\smooth\rough.

Usage Notes

• See also: Using the Intersector and ListConcatenator to Solve Problems

• About Attribute Lists

Configuration

Parameters

General

List Attribute	Select the attribute that will supply the list containing the values you want to concatenate.
Separator Character	Characters can be expressed as regular characters but they can also include any number of control characters. Special character sequences are interpreted as shown below: Sequence Description Ctrl+Shift+h (^H) Backspace (0x08) Ctrl+Shift+l (^L) Form feed (0x0c) Ctrl+Shift+j (^J) Newline (0x0a) Ctrl+Shift+r (^M) Carriage return (0x0d) Ctrl+Shift+i (^I) Tab (0x09) Ctrl+Shift+k (^K) Vertical tab (0x0b)
Drop Empty and Null Elements	Determines whether to concatenate list elements whose value is empty or null. Missing attributes are never concatenated. To treat missing attributes as empty or null, use an upstream NullAttributeMapper. By default, all attribute values will be concatenated, whether or not they are empty. If this parameter value is set to Yes, then only non-empty values will be concatenated.

Output Attribute Name

Destination

Name the attribute to contain the concatenated list values.

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

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