• In this example, three new attributes are added to the input features:
• UPDATEDBY is added and set to the constant value “Smith”.
• X and Y are added, and set to the feature’s coordinates by extracting geometry with an FME function.

The new attributes are reflected in the transformer, at the top of the attribute list.

The attribute values are updated, and can be viewed in the Data Inspector’s table view.

 

Adjacent Feature Attributes are accessed under Advanced: Attribute Value Handling. When turned on, you can specify a number of features preceding and following the current feature to reference in calculating new values.

Suppose we are given the dataset below:

ID	Latitude	Longitude
0	49.1640	-123.061
1	49.1643	-123.063
2	49.1642	-123.062
3	49.1642	-123.064

 

If the Number of Prior Features and Number of Subsequent Features parameters are both set to 2, then when the first feature is read, the AttributeCreator has access to the following features:

Feature Reference	ID	Latitude	Longitude
feature[-2]	<missing>	<missing>	<missing>
feature[-1]	<missing>	<missing>	<missing>
current feature	0	49.1640	-123.061
feature[+1]	1	49.1643	-123.063
feature[+2]	2	49.1642	-123.062

 

Note that some attributes are missing because no features exist prior to the first feature.

After the second feature is read, the window of prior and subsequent features available to the AttributeCreator shifts to produce the following:

Feature Reference	ID	Latitude	Longitude
feature[-2]	<missing>	<missing>	<missing>
feature[-1]	0	49.1640	-123.061
current feature	1	49.1643	-123.063
feature[+1]	2	49.1642	-123.062
feature[+2]	3	49.1642	-123.064

 

This statement would calculate the average latitude of the two preceding features:

Calculations referencing adjacent features can be created in the Arithmetic Editor and the Text Editor. These editors will list the attributes of the currently processed feature first, then the prior features, then the subsequent features.

This transformer accepts any feature.

Features with the new attributes and optionally defined values.

When an AttributeCreator is opened for the first time, this area will contain a blank row where a new attribute can be created. Additional rows are added as entries are made.

New Attribute

Enter the name of the new attribute.

Attribute Value

New attributes can be left without a value for use elsewhere, or you can set new values here by clicking in the appropriate row and: Entering a new constant value Entering an expression Selecting another attribute to copy values from Using any of the available tools in the drop-down context menu to create expressions, formulas, conditional values, and more. The ellipses button will open the Text Editor, and the arrow button provides further options on the context menu. See Defining Values below for detailed information on using these options.

Expanding the Advanced section provides access to the attributes of adjacent features that can be used to define values. While this section may appear complex, most users will rarely need this functionality.

Check “Enable Adjacent Feature Attributes” to use this feature.

You can now set an attribute value (in the Attribute Actions matrix) based on the attributes of features prior or subsequent to the current feature by referencing them as follows:

• Attributes of prior features are referenced as feature[-1].AttrName, feature[-2].AttrName, etc.
• Attributes of subsequent features are referenced as feature[+1].AttrName, feature[+2].AttrName, etc.
• Attributes of the currently processed feature are accessed directly without a prefix, such as AttrName.

When retrieving the value of a prior feature, any changes made by the AttributeCreator to that feature will take effect.

Number of Prior Features

This parameter specifies the maximum number of prior features that can be referenced by the AttributeCreator. If Multiple Feature Attribute Support is enabled, this must be a value from 0 to 100. As additional features must be read for each feature processed, defining only the maximum number of features needed to be retrieved will improve performance.

Number of Subsequent Features

This parameter specifies the maximum number of subsequent features that can be referenced by the AttributeCreator. If Multiple Feature Attribute Support is enabled, this must be a value from 0 to 100. As additional features must be read for each feature processed, defining only the maximum number of features needed to be retrieved will improve performance.

Substitute Missing, Null, and Empty by

This parameter specifies the desired behavior when the referenced attribute does not exist, has a null value, or has an empty string value.

Such attributes can be thought of as unresolved attributes. For example, since there are no features prior to the first input feature, the AttributeCreator will fail to resolve the value of feature[-1].AttrName for the first input feature.

If this parameter is set to No Substitution, the AttributeCreator will resolve all unresolved attributes with an empty string if they are used in a larger expression. If the unresolved attribute is assigned directly and is not part of a larger expression, then the New Attribute will be unresolved in the same way. For example, if B is missing, and A is set to @Value(B), then A will be missing as well. But if A is set to "B = @Value(B)", A will have the value of "B = ".

As another example, if the value of feature[+2] is the empty string and Default Value is specified, then the empty string will be treated as an unresolved attribute, and will be resolved as the value specified under Default Value.

If this parameter is set to Closest Adjacent Feature, then the unresolved attributes will be resolved as the corresponding attribute of the closest feature, if such a feature exists. When looking for closest features, features with unresolved attributes are skipped. If a prior or subsequent feature has unresolved attributes, it is possible that the current feature is used to resolve the missing attributes.

For example, if the value of feature[-2].AttrName is unresolved, then to resolve the value of feature[-2].AttrName the AttributeCreator will look at the closest features to feature[-2], alternating between features prior to and subsequent to feature[-2]. It will first look at feature[-3].AttrName, followed by feature[-1].AttrName if needed, and then feature[-4].AttrName if needed, until all prior and subsequent features specified have been exhausted.

If the attribute remains unresolved within the specified prior and subsequent features, then it will be resolved as the value specified in the Default Value parameter.

Default Value

This parameter specifies the value used to resolve unresolved attributes in these cases:

• Substitute Missing, Null and Empty by: is set to Default Value
• Substitute Missing, Null and Empty by: is set to Closest Adjacent Feature and a value is not found in within the number of prior and subsequent features specified.

Row Reordering	Enabled once you have clicked on a new attribute in the list. 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
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	The import button will populate the transformer with a set of new attributes read from a dataset. If the transformer already contains new attribute entries, these attributes will be appended to the existing list.

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 - whether entered directly in a parameter or constructed using one of the editors.

AttributeCopier

AttributeKeeper

AttributeManager

AttributeRemover

AttributeRenamer

AttributeValueMapper

BulkAttributeRenamer

BulkAttributeRemover