Working with Filters
This section explains how to create translation unit filters for operations such as import, export, and search.
Overview
Translation unit filters are represented by the abstract FilterExpression class. This class represents a Boolean expression that works on translation unit fields. Two concrete classes derive from it:
- AtomicExpression: A filter expression that compares a single translation unit field against a specified value by using a specified operator.
- ComposedExpression: A filter expression that builds complex filter expressions from other filter expressions, either by combining two filter expressions by using the AND or NOT operator, or by negating a filter expression. Composed filter expressions can be nested.
The field values (FieldValue) that you can use in an atomic filter expression include:
- User-defined fields: See Working with Field Definitions.
- System fields: These are built-in translation unit fields, as defined in SystemFieldDefinitions.
