How to get data from another EntityProxy in GXT ColumnConfig?

Question

Here is the thing: I have an application to manage user's tickets. I have 2 basic classes : Ticket and User. Using GXT I have some ColumnConfig class like this:

ColumnConfig<TicketProxy, String> dateColumn = new ColumnConfig<TicketProxy, String>(
        new ValueProvider<TicketProxy, String>() {
            public String getValue(TicketProxy object) {
                Date initialDate = object.getInitialDate();
                String date = "";
                if (initialDate != null) {
                    date = dtFormat.format(initialDate);
                }
                return date;
            }

            public void setValue(TicketProxy object, String initialDate) {
                if (object instanceof TicketProxy) {
                    object.setInitialDate(dtFormat.parse(initialDate));
                }
            }

            public String getPath() {
                return "initialDate";
            }
        }, 70, "Date");
columnsChamado.add(dateColumn);

but I want to get some data from UserProxy class, some like this:

ColumnConfig<UserProxy, String> userRoomColumn = new ColumnConfig<UserProxy, String>(
                new ValueProvider<UserProxy, String>() {
                    public String getValue(UserProxy object) {
                        String userRoom = object.getUserRoom();
                        String room = "";
                        if (userRoom != null) {
                            room = userRoom;
                        }
                        return room;
                    }

                    public void setValue(UserProxy object, String userRoom) {
                        if (object instanceof UserProxy) {
                            object.setUserRoom(userRoom);
                        }
                    }

                    public String getPath() {
                        return "userRoom";
                    }
                }, 70, "User's Room");
        columnsChamado.add(userRoomColumn);

But GWT doesn't allow me to change the "Proxy" parameter to another class in the same ColumnConfig.

How can I get data from other Proxy class in this ColumnConfig?

I use GXT 3.0 (Sencha) + Hibernate.

Proxy classes: BaseEntityProxy:

package com.acme.ccc.shared;

import com.acme.ccc.server.locator.CCCLocator;
import com.acme.db.base.DatabaseObject;

import com.google.web.bindery.requestfactory.shared.EntityProxy;
import com.google.web.bindery.requestfactory.shared.ProxyFor;
import com.google.web.bindery.requestfactory.shared.SkipInterfaceValidation;

@SkipInterfaceValidation
@ProxyFor(value = DatabaseObject.class, locator = CCCLocator.class)
public interface BaseEntityProxy extends EntityProxy {
    Long getId();
    Long getVersion();
    void setId(Long id);
    void setVersion(Long version);
}

TicketProxy:

package com.acme.ccc.shared.entityproxy;

import java.util.Date;
import java.util.List;

import com.acme.ccc.db.Ticket;
import com.acme.ccc.server.locator.CCCLocator;
import com.acme.ccc.shared.BaseEntityProxy;

import com.google.web.bindery.requestfactory.shared.ProxyFor;


@ProxyFor(value = Ticket.class, locator = CCCLocator.class)
public interface TicketProxy extends BaseEntityProxy {
    Date getPrazo();
    void setPrazo(Date prazo);

    TicketTipoProxy getTicketTipo();
    void setTicketTipo(TicketTipoProxy chamadoTipo);

    CanalOrigemProxy getCanalOrigem();
    void setCanalOrigem(CanalOrigemProxy canalOrigem);

    UserProxy getUser();
    void setUser(UserProxy user);

    CategoriaProxy getPedidoTipo();
    void setPedidoTipo(CategoriaProxy pedidoTipo);

    Date getInitialDate();
    void setInitialDate(Date dt);

    Long getTotal();
    void setTotal(Long total);

}

UserProxy:

package com.acme.ccc.shared.entityproxy;

import java.util.List;

import com.acme.ccc.db.User;
import com.acme.ccc.server.locator.CCCLocator;
import com.acme.ccc.shared.BaseEntityProxy;

import com.google.web.bindery.requestfactory.shared.ProxyFor;

@ProxyFor(value = User.class, locator = CCCLocator.class)
public interface UserProxy extends BaseEntityProxy {
    String getName();
    String getUserRoom();
    Long getTotal();

    void setName(String name);
    void setUserRoom(Sting room)
    void setTotal(Long total);
}

Answer 1

An gxt grid is able to show the data only of one data type. If you put a single TicketProxy row, how do you expect to access a user object?

If you want to display both Tickets and Users independently (so a row is either a Ticket OR a User), you have to use BaseEntityProxy in your Grid: Grid<BaseEntityProxy>. Then you can define your columns as ColumnConfig<BaseEntityProxy, ?> and check the type within your getters and setter:

List<ColumnConfig<BaseEntityProxy, ?>> columnsChamado = new ArrayList<ColumnConfig<BaseEntityProxy, ?>>();
ColumnConfig<BaseEntityProxy, String> dateColumn = new ColumnConfig<BaseEntityProxy, String>(
        new ValueProvider<BaseEntityProxy, String>() {

            private final DateTimeFormat dtFormat = DateTimeFormat.getFormat(DateTimeFormat.PredefinedFormat.DATE_FULL);

            public String getValue(BaseEntityProxy object) {
                Date initialDate =  ((TicketProxy) object).getInitialDate();
                String date = "";
                if (initialDate != null) {
                    date = dtFormat.format(initialDate);
                }
                return date;
            }

            public void setValue(BaseEntityProxy object, String initialDate) {
                if (object instanceof TicketProxy) {
                    ((TicketProxy) object).setInitialDate(dtFormat.parse(initialDate));
                }
            }

            public String getPath() {
                return "initialDate";
            }
        }, 70, "Date");

columnsChamado.add(dateColumn);

ColumnConfig<BaseEntityProxy, String> userRoomColumn = new ColumnConfig<BaseEntityProxy, String>(
        new ValueProvider<BaseEntityProxy, String>() {
            public String getValue(BaseEntityProxy object) {
                String userRoom = ((UserProxy)object).getUserRoom();
                String room = "";
                if (userRoom != null) {
                    room = userRoom;
                }
                return room;
            }

            public void setValue(BaseEntityProxy object, String userRoom) {
                if (object instanceof UserProxy) {
                    ((UserProxy)object).setUserRoom(userRoom);
                }
            }

            public String getPath() {
                return "userRoom";
            }
        }, 70, "User's Room");
columnsChamado.add(userRoomColumn);

ColumnModel<BaseEntityProxy> cm = new ColumnModel<BaseEntityProxy>(columnsChamado);

If, on the other hand, you want one grid row to display a User AND a Ticket, you have to use a wrapper class:

class TicketWithUserProxy extends BaseEntityProxy{

    private UserProxy userProxy;
    private TicketProxy ticketProxy;

    public UserProxy getUserProxy() {
        return userProxy;
    }

    public void setUserProxy(UserProxy userProxy) {
        this.userProxy = userProxy;
    }

    public TicketProxy getTicketProxy() {
        return ticketProxy;
    }

    public void setTicketProxy(TicketProxy ticketProxy) {
        this.ticketProxy = ticketProxy;
    }
}

and setup your grid (Grid<TicketWithUserProxy>) accordingly:

List<ColumnConfig<TicketWithUserProxy, ?>> columnsChamado = new ArrayList<ColumnConfig<TicketWithUserProxy, ?>>();

ColumnConfig<TicketWithUserProxy, String> dateColumn = new ColumnConfig<TicketWithUserProxy, String>(
        new ValueProvider<TicketWithUserProxy, String>() {

            private final DateTimeFormat dtFormat = DateTimeFormat.getFormat(DateTimeFormat.PredefinedFormat.DATE_FULL);

            public String getValue(TicketWithUserProxy object) {
                Date initialDate =  object.getTicketProxy().getInitialDate();
                String date = "";
                if (initialDate != null) {
                    date = dtFormat.format(initialDate);
                }
                return date;
            }

            public void setValue(TicketWithUserProxy object, String initialDate) {
                object.getTicketProxy().setInitialDate(dtFormat.parse(initialDate));
            }

            public String getPath() {
                return "initialDate";
            }
        }, 70, "Date");

columnsChamado.add(dateColumn);

ColumnConfig<TicketWithUserProxy, String> userRoomColumn = new ColumnConfig<TicketWithUserProxy, String>(
        new ValueProvider<TicketWithUserProxy, String>() {
            public String getValue(TicketWithUserProxy object) {
                String userRoom = object.getUserProxy().getUserRoom();
                String room = "";
                if (userRoom != null) {
                    room = userRoom;
                }
                return room;
            }

            public void setValue(TicketWithUserProxy object, String userRoom) {
                object.getUserProxy().setUserRoom(userRoom);
            }

            public String getPath() {
                return "userRoom";
            }
        }, 70, "User's Room");
columnsChamado.add(userRoomColumn);
ColumnModel<TicketWithUserProxy> cm = new ColumnModel<TicketWithUserProxy>(columnsChamado);

Answer 2

If you have a Column of TicketProxy, you can get the UserProxy from the TicketProxy ?

ColumnConfig<TicketProxy, String> userRoomColumn = new ColumnConfig<TicketProxy, String>(
     new ValueProvider<TicketProxy, String>() {
          public String getValue(TicketProxy object) {
              String userRoom = object.getUser().getUserRoom();
              String room = "";
              if (userRoom != null) {
                  room = userRoom;
              }
              return room;
          }

          public void setValue(TicketProxy object, String userRoom) {
              object.getUser().setUserRoom(userRoom);
          }

          public String getPath() {
              return "user.userRoom";
          }
     }, 70, "User's Room");
columnsChamado.add(userRoomColumn);