@Named
@ViewScoped
public class DropdownView implements Serializable {
    
	private Map<String,Map<String,String>> data = new HashMap<String, Map<String,String>>();
    private String country;  
    private String city;
    private Map<String,String> countries;
	private Map<String,String> cities;
    
    @PostConstruct
    public void init() {
        countries  = new HashMap<String, String>();
        countries.put("USA", "USA");
        countries.put("Germany", "Germany");
        countries.put("Brazil", "Brazil");
        
        Map<String,String> map = new HashMap<String, String>();
		map.put("New York", "New York");
		map.put("San Francisco", "San Francisco");
		map.put("Denver", "Denver");
        data.put("USA", map);
        
        map = new HashMap<String, String>();
		map.put("Berlin", "Berlin");
		map.put("Munich", "Munich");
		map.put("Frankfurt", "Frankfurt");
        data.put("Germany", map);
        
        map = new HashMap<String, String>();
        map.put("Sao Paulo", "Sao Paulo");
        map.put("Rio de Janerio", "Rio de Janerio");
        map.put("Salvador", "Salvador");
        data.put("Brazil", map);
    }

    public Map<String, Map<String, String>> getData() {
        return data;
    }

    public String getCountry() {
        return country;
    }

    public void setCountry(String country) {
        this.country = country;
    }

    public String getCity() {
        return city;
    }

    public void setCity(String city) {
        this.city = city;
    }

    public Map<String, String> getCountries() {
        return countries;
    }

    public Map<String, String> getCities() {
        return cities;
    }

    public void onCountryChange() {
		if(country !=null && !country.equals(""))
			cities = data.get(country);
		else
			cities = new HashMap<String, String>();
	}
    
    public void displayLocation() {
        FacesMessage msg;
        if(city != null && country != null)
            msg = new FacesMessage("Selected", city + " of " + country);
        else
            msg = new FacesMessage(FacesMessage.SEVERITY_ERROR, "Invalid", "City is not selected."); 
            
        FacesContext.getCurrentInstance().addMessage(null, msg);  
    }
}