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ExpressionFilter

Filters row with a custom filtering. More...

Import Statement: import Felgo 3.0
Since: Felgo 2.18.1
Inherits:

Filter

Properties

Detailed Description

An ExpressionFilter is a Filter allowing to implement custom filtering based on a javascript expression.

Property Documentation

expression : expression

An expression to implement custom filtering, it must evaluate to a boolean. It has the same syntax has a Property Binding except it will be evaluated for each of the source model's rows. Rows that have their expression evaluating to true will be accepted by the model. Data for each row is exposed like for a delegate of a QML View.

This expression is re-evaluated for a row every time its model data changes. When an external property (not index or in model) the expression depends on changes, the expression is re-evaluated for every row of the source model. To capture the properties the expression depends on, the expression is first executed with invalid data and each property access is detected by the QML engine. This means that if a property is not accessed because of a conditional, it won't be captured and the expression won't be re-evaluated when this property changes.

A workaround to this problem is to access all the properties the expressions depends unconditionally at the beginning of the expression.