Does ValueXPath support XPath functions

[anja_burrmann]

I want to concat two fields from my RestDataSource for the calendar title.

Since calendars seem to have no equivalent to ListGridField, I guess the only option is to combine it already in the DataSourceField.

I try to achieve this by using the XPath function concat:

        RestDataSource dataSource = new RestDataSource();
        dataSource.setFetchDataURL(Constants.REST_API + link);
	dataSource.setRecordXPath("//record");
	dataSource.setDataFormat(DSDataFormat.XML);

	DataSourceTextField textField = new DataSourceTextField("text");
	
	// Register name for xpath functions
	XmlNamespaces namespaces = new XmlNamespaces();
	namespaces.addNamespace("fn","http://www.w3.org/2005/xpath-functions");
	dataSource.setXmlNamespaces(namespaces);

	// Use xpath function
	textField.setValueXPath("fn:concat(field1,field2)");

But the result is always the string "undefined".

Can I use at all XPath functions in ValueXPath? If so: How do I register the functions?

[Isomorphic]

Use transformResponse or a FieldValueExtractor to add custom logic to how values are derived from the response.

[anja_burrmann]

Thanks a lot for the hint, Isomorphic!

In case somebody stumbles over the same issue:

DataSourceTextField textField = new DataSourceTextField("text");
textField.setFieldValueExtractor(new FieldValueExtractor() {
	@Override
	public Object execute(Object record, Object value,
			DataSourceField field, String fieldName) {
		String field1 = XMLTools.selectString(record, "field1");
		String field2 = XMLTools.selectString(record, "field2");
		return field1 + field2;
	}
});