question: private void tryParseElExpression ( final IDOMAttr attr ) { final IRegion attrValueRegion = XmlUtilities . getAttributeValueRegion ( attr ) ; String attrValue = attr . getNodeValue ( ) ; if ( attrValueRegion == null || attrValue == null ) { return ; } List < IRegion > exprContentRegions = UiBinderUtilities . getElExpressionRegions ( attrValue ) ; for ( final IRegion exprContentRegion : exprContentRegions ) { String exprContents = attrValue . substring ( exprContentRegion . getOffset ( ) , exprContentRegion . getOffset ( ) + exprContentRegion . getLength ( ) ) ; ElExpressionFirstFragment firstFragment = UiBinderUtilities . findMatchingElExpressionFirstFragment ( exprContents , firstFragmentComputer . getFirstFragments ( ) ) ; if ( firstFragment == null ) { setFieldReferenceFirstFragmentUndefinedError ( attrValueRegion , exprContentRegion , exprContents ) ; continue ; } String allButFirstFragment = UiBinderUtilities . getAllButFirstFragment ( exprContents ) ; int allButFirstFragmentOffsetInDoc = attrValueRegion . getOffset ( ) + exprContentRegion . getOffset ( ) + ( exprContents . length ( ) - allButFirstFragment . length ( ) ) ; IType fieldType = UiBinderXmlModelUtilities . resolveElementToJavaType ( ( IDOMElement ) firstFragment . getNode ( ) , javaProject ) ; if ( UiBinderXmlModelUtilities . isStyleElement ( firstFragment . getNode ( ) ) ) { Region fieldRefRegion = new Region ( exprContentRegion . getOffset ( ) + attrValueRegion . getOffset ( ) , exprContentRegion . getLength ( ) ) ; tryParseCssElExpression ( ( IDOMElement ) firstFragment . getNode ( ) , allButFirstFragment , allButFirstFragmentOffsetInDoc , fieldRefRegion ) ; } else if ( fieldType != null ) { tryParseJavaElExpression ( fieldType , allButFirstFragment , allButFirstFragmentOffsetInDoc ) ; } } }
target:  Parses a field reference within an attribute.