Creating REST service to get complex node type
Views Datasource is very popular module to return json, xml or any other type of data. 


  
    Views Datasource is a set of plugins for Drupal Views for rendering content in a number of shareable, reusable formats based on XML, JSON and XHTML.
  


Install the module. Create the view that return your node. then under format select data source as json. You can only select the field you want to render in field settings.