Help with Javascript Condition Formatter

Hi Experts, regarding with the documentation for Joget Version 6 in the datalist now we have a new feature to set the format in the columns , Javascript Condition Formatter  i´m using a couple of javascript expression to validate and format the rows but don´t work , the Datalist is using a table that have numbers stored without thousand separators and i´m needing show the value in European format.

To Validate i did use :

parseInt({total_prop}) > 1  

note: the validation work fine because.

To set the format I did use:

 {total_prop} = new Intl.NumberFormat ('de-DE', { style: 'currency', currency: 'EUR' }).format({total_prop})

and 

new Intl.NumberFormat ('de-DE', { style: 'currency', currency: 'EUR' }).format({total_prop})

note: the format does not work because don´t show anything 

Could you help me to check in a on premise installation which could be the log in order to undertand the problem?.