void TestQgsDataDefined::referencedColumns()
{
QgsDataDefined dd;
dd.setActive( true );
dd.setUseExpression( true );
QStringList cols = dd.referencedColumns();
QVERIFY( cols.isEmpty() );
//set as expression
dd.setExpressionString( "1+col1+col2" );
cols = dd.referencedColumns();
QCOMPARE( cols.length(), 2 );
QVERIFY( cols.contains( QString( "col1" ) ) );
QVERIFY( cols.contains( QString( "col2" ) ) );
//alter expression and check that referenced columns is updated
dd.setExpressionString( "1+col1+col2+col3" );
cols = dd.referencedColumns();
QCOMPARE( cols.length(), 3 );
QVERIFY( cols.contains( QString( "col1" ) ) );
QVERIFY( cols.contains( QString( "col2" ) ) );
QVERIFY( cols.contains( QString( "col3" ) ) );
//switch to field
dd.setUseExpression( false );
cols = dd.referencedColumns();
QVERIFY( cols.isEmpty() );
dd.setField( "field" );
cols = dd.referencedColumns();
QCOMPARE( cols.length(), 1 );
QVERIFY( cols.contains( QString( "field" ) ) );
//switch back to expression
dd.setUseExpression( true );
cols = dd.referencedColumns();
QCOMPARE( cols.length(), 3 );
QVERIFY( cols.contains( QString( "col1" ) ) );
QVERIFY( cols.contains( QString( "col2" ) ) );
QVERIFY( cols.contains( QString( "col3" ) ) );
}
