- XML (Extensible Markup Language) Reader/Writer
- XML Quick Facts
- Workbench XML Reader Parameters
- Workbench XML Writer Parameters
- Feature Representation
- Mapping File Reference
- xfMap
- Reading the Input XML Document
- Mapping Rules
- Types of Mapping Rules
- Match and Except Expression
- Specifying Several Match Expressions for One Mapping Rule
- Limiting Mapping Rule Activation with Except Expressions
- Mapping Rule States (activation, execution, suspension, and de-activation)
- Using Force Elements During Mapping Rule Activation and Deactivation
- Search-sets
- Expression Elements (Extract and Literal)
- Expression Sequence
- Feature Mapping Rules
- FME Feature Construction
- Feature Type Element
- Attributes Element
- FME Feature Construction (defining mapping rules under the <feature-content-map> element)
- Attribute Element (handling multiple values)
- Attribute Element (handling optional attributes)
- Attribute Element (sequenced attributes)
- Attribute Element (Nillable Attributes)
- Geometry Element
- Geometry Builder States (activation, execution, suspension, and de-activation)
- Geometry Construction
- Composite Geometry Builders
- Built-in Geometry Builders
- Mapping Segmented Geometric Information
- Geometry Traits (trait element)
- FME Feature Construction (constructing multiple features at a time)
- Structure Element
- References Element
- Apply References Element
- Group Mapping Rules
- Reference Mapping Rules
- Mapping Rules (Optional Elements)
- More Expression Elements
- FME Schema Features
- Reading the Input XML Document
Each attribute specified with the <attribute> element is added by default to an FME feature. A user may not want an attribute included in an FME feature when the expression sequence of an attribute’s value evaluates to the empty string. The <attribute> element has an optional required attribute that specifies if the attribute is to be given to the feature based on the evaluated expression sequence of its value. The valid values for the required attribute are true and false, with its default value being true.
If the optional required attribute is set to false, then the attribute will not be given to the feature when the expression sequence of its value evaluates to the empty string. The following xfMap fragment sets the required attribute to false.
<attribute required="false"> <name> <literal expr="my-optional-attribute"/> </name> <value> <extract expr="."/> </value> </attribute>