ListSearcher
Searches a list to find a value and returns the index of the value in the list.
Example
For example, if this feature enters the transformer:
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 the somelist{}.kind list attribute is searched for the value smooth, then the index attribute would be set to 1.
Output feature order may be controlled with the Advanced > Preserve Feature Order parameter.
Configuration
Output Ports
An element in the list matched. The output feature will return the index of the found element in the index attribute specified.
If the element is not found in the input feature, the feature will be output via this port and no index attribute will be applied.
Parameters
List Attribute |
The name of the list to search. The list name should contain a pair of braces {}. |
||||||||||
Search Type |
This parameter determines how the list will be searched.
|
||||||||||
Search For |
The string or regular expression to search in the list. |
If enabled, the contents of the found element will be copied to the main attribute(s) of the output feature. This saves adding a ListIndexer after the searcher to demote the list element.
Note that any list element attributes that start with fme_ will not be copied (for example, fme_type) unless you specify a Copied Attribute Prefix.
Copied Attribute Prefix |
The prefix that should be added to any attribute(s) copied onto the output feature. |
Preserve Feature Order |
This parameter controls the order in which features exit a transformer. When a transformer has more than one output port, features usually exit one port at a time. At times, it may be useful to keep the order that features arrived in, switching from port to port as necessary. This allows feature order to be preserved, though at a potential cost in processing efficiency. Select a method for feature ordering.
|
Matching List Index |
If the Index Attribute is specified and the search string is found, an attribute with the specified name will be added to the output feature containing the index of the found element. |
Additional Resources
Test regular expressions with Rubular, a Ruby-based regular expression editor.
Editing Transformer Parameters
Using a set of menu options, transformer parameters can be assigned by referencing other elements in the workspace. More advanced functions, such as an advanced editor and an arithmetic editor, are also available in some transformers. To access a menu of these options, click beside the applicable parameter. For more information, see Transformer Parameter Menu Options.
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. There are a number of tools and shortcuts that can assist in constructing values, generally available from the drop-down context menu adjacent to the value field.
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.
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.
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.
These functions manipulate and format strings. | |
Special Characters |
A set of control characters is available in the Text Editor. |
Math functions are available in both editors. | |
Date/Time Functions | Date and time functions are available in the Text Editor. |
These operators are available in the Arithmetic Editor. | |
These return primarily feature-specific values. | |
FME and workspace-specific parameters may be used. | |
Creating and Modifying User Parameters | Create your own editable parameters. |
Dialog Options - Tables
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:
|
Cut, Copy, and Paste
|
Enabled once you have clicked on a row item. Choices include:
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.
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 samples and information about this transformer on the FME Community.