Searches a list to find a value and returns the index of the value in the list.
Output Ports
Found
An element in the list matched. The output feature will return the index of the found element in the index attribute specified.
NotFound
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.
| Parameter Choice | Description |
|---|---|
|
First Exact Match |
Searches for an exact match. |
|
First regular expression match |
Uses a regular expression to search for a first matching entry in the list. Advanced Regular Expressions (AREs) are supported. Advanced Regular Expressions (AREs) are supported. For a complete description of AREs, see Syntax of Perl-Compatible Regular Expressions at http://perldoc.perl.org/perlre.html#Regular-Expressions. In brief, an ARE is one or more branches, separated by `|', matching anything that matches any of the branches. |
|
First not matching |
Returns the index of the first non-matched entry in the list. |
|
First less than, |
Searches for the first element in the list that satisfies the criteria. Numerical comparisons are used if both the list element and the search value can be converted to floating point numbers; otherwise, string comparisons are used |
Search For
The string or regular expression to search in the list.
Index Attribute
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.
Copy Found List Element
If checked, 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.
Advanced
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.
| Per Output Port (Default) |
Only preserve the input order of features as they occur within the group of features exiting a given output port. All features exiting an output port retain their ordering relative to each other (within the group), but not relative to features exiting other output ports. This option is generally the most efficient, where large chunks of features will exit an output port together (taking advantage of bulk mode). As features exiting different output ports may not be strictly output in the order they arrived, output ordering may be unpredictable. |
| Across Output Ports |
Strictly preserve the input order of features, regardless of which output port they exit. Features will be output singly in the same order they arrived, switching from port to port as necessary. This option is generally less efficient as the processing gains of bulk mode are less likely to apply - however, feature order is predictable. |
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.
Usage Notes
- Output feature order may be controlled with the Advanced > Preserve Feature Order parameter.
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.
Transformer Categories
FME Community
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