AttributeExploder

Creates value pairs (attribute name and attribute value) for every attribute on a feature, and either adds them to a list attribute or creates new features (one for each pair) with new attributes containing both values. In either case, original attributes and geometry may be kept or discarded.

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Typical Uses

Transposing or manipulating tabular data (such as spreadsheets)
Melting data
Extracting the attribute schema from features for use in dynamic translation attribute mappings
Extracting the attribute schema from features to write as metadata/documentation
Preparing data for charts and reports

How does it work?

The AttributeExploder receives features with attributes, and extracts both the attribute names and their values. It can do one of two things with them (the Exploding Type) - either create multiple new features (one for each attribute), or add the information to the original feature as a list attribute.

The following examples demonstrate both Exploding Types, as they apply to a single feature. Note that in both cases, extra attributes that are normally unexposed are also exploded, including reader and internal fme_ attributes.

You may opt to either keep or discard the original attributes and geometry - in these examples, they are discarded.

Exploding Type: Features

If the attributes are exploded into Features, each input feature will become many - one for every attribute in the original feature. The new features will have both the original attribute names and values added as new attributes. Below, we use the default new attribute names _attr_name and _attr_value.

One (1) feature becomes twelve (12).

In the case of a spreadsheet, where a row is considered a single feature, this is the equivalent of exploding every cell into its own feature.

Exploding Type: List

If the attributes are exploded into a List, a new list attribute is added to the original feature.

The attribute names and values are added as list elements.

One (1) feature in produces one (1) feature out, with a list attribute.

Examples

Usage Notes

The AttributeExploder is commonly used in manipulating tabular data, from simple transposition to more complex tasks. See articles on the FME Community for detailed examples.
To unmelt (reverse melt) data, see the AttributeCreator (alias UnMelter).

Configuration

Input Ports

Output Ports

Parameters

General

Exploding Type

Features: One feature is output for each original attribute. Each output feature will have two new attributes: one named by Exploded Attribute (whose value will be the initial attribute's name) and one by Exploded Value (whose value will be the initial attribute's value).

List: The processed feature will have a new list attribute defined by List Name which will contain one entry (with attribute name and attribute value members, named by Exploded Attribute and Exploded Value) for each attribute of the feature.

Note: List attributes are not accessible from the output schema in Workbench unless they are first processed using a transformer that operates on them, such as ListExploder or ListConcatenator. Alternatively, AttributeExposer can be used.

Keep Geometry

If Yes, each output feature will have the same geometry as the given input feature. Otherwise, output features will have no geometry.

Keep Attributes

If Yes, the initial attributes on the processed features are preserved. Otherwise, output features will only have the attributes created by this factory.

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.

Reference

Processing Behavior	Feature-Based
Feature Holding	No
Dependencies	None
Aliases	Melter
History

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 AttributeExploder on the FME Community.

Examples may contain information licensed under the Open Government Licence – Vancouver and/or the Open Government Licence – Canada.

Exploded Attribute	Name the attribute to contain the name of the extracted attribute.
Exploded Value	Name the attribute to contain the value of the extracted attribute.
List Name	If Exploding Type is List, enter a name for the list attribute.