Type mismatch: cannot convert from Request<capture#1-of ?> to Request<EmployeeProxy>

[Matthew Hill]

The following line of code throws the above error:

Request<EmployeeProxy> request = requestFactory.find(employee.stableId());

employee is just an EmployeeProxy instance.

What's wrong?

[zixzigma]

it might be that you need to get the employeeRequest first, before
invoking find on it

requestFactory.employeeRequest().find(xxxx).fire

[Matthew Hill]

I'm going to try using my own find method on employeeRequest, like you said.

Request<EmployeeProxy> request = requestFactory.employeeRequest().findEmployee(employee.getId());

Not quite sure what all of this stableId stuff is. Anyone care to explain? 

[Thomas Broyer]

Nothing's wrong (apart from generics in Java, once again).

Have a look at the JavaDoc for stableId:

Subtypes should override to declare they return a stable id of their own type, to allow type safe use of the request objects returned by RequestFactory.find(EntityProxyId).

http://google-web-toolkit.googlecode.com/svn/javadoc/2.1/com/google/gwt/requestfactory/shared/EntityProxy.html#stableId()

In other words, either you type-cast and add a @SuppressWarnings("unchecked"), or (better) you re-define stableId in each of your EntityProxy that you intend to use with RequestFactory#find, e.g.:

  EntityProxyId<EmployeeProxy> stableId();

[zixzigma]

is it enough to just declare the stableId property
or we also need to provide implementation ?


and one question about Version.
does RequestFactory depend on version property ?
who generates the version number ?
is it the RequestFactory that does it? everytime a proxy changes
value ?

[Matthew Hill]

Right. So from the overridden stableId method I return the unique ID which I'm using for my persistence?

And then what happens when you call RequestFactory#Find? How does it 'find' the proxy?

[Matthew Hill]

I've got it now. I just need to add it to the interface.