ParameterFetcher

Adds an attribute to the feature, supplying it the value of a previously published parameter.

A parameter is a setting that you can pass values into when a translation is run. Parameters usually relate to a setting on a reader or transformer. The ParameterFetcher can be used to copy the value of one or more parameters to a corresponding number of attributes. The number of rows specified in the configuration dialog determine the number of exposed output attributes.

Example

This example describes a single parameter but you can fetch multiple parameters.

The Creator transformer shown below has a published parameter called NUM. To publish this parameter, place the Creator transformer in the workspace. Then right-click on Number to Create and select Create Parameter.

The dialog shows the Published Parameter properties, with the default value changed to 10:

Choose the NUM parameter in the Parameter Name field, and type a Target Attributeresult.

When the workspace is run, the ParameterFetcher fetches the value assigned to the "NUM" parameter and stores it in the "result" attribute. Now the feature has an attribute "result" which holds the value of the "NUM" parameter.

You can see the attribute and its value in the FME Universal Viewer.

Note: For more information on Published Parameters, see the Workbench help topic Adding a Parameter.

Configuration

Parameters

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.

How to Set Parameter Values

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

Transformers with table-style parameters have additional tools for populating and manipulating values.

Table Tools

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.

FME Community

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Search for samples and information about this transformer on the FME Community.

Parameter Name	When the ParameterFetcher is connected, the Parameter Name drop-down list shows the parameters that can be fetched from the workspace. The Parameter Name also exposes FME Parameters and FME Server Parameters.
Target Attribute	The target attribute is the name of the attribute that will be created. When you select a parameter, this field is automatically filled with an appropriate name (for example, selecting a parameter named WIDTH will automatically name the target attribute _WIDTH). You can use the default name, or type a new name.