Databinding a Bean as a property of another bean

[tch]

I would like to bind a property from another bean, however the UI only lets me selects a bean that exists, not step through an existing bean.

So in order to bind a simple value like a Department from an Employee bean named employee I have to do:

Code: Select all

Department department = employee.getDepartment();


Now I can select the department bean and end up with generated code like:

Code: Select all

IObservableValue observeValue = BeansObservables.observeValue(department, "labelNm");


What I would like to be able to do is simply:

Code: Select all

IObservableValue boProjMgrIdObserveValue = BeansObservables.observeValue(employee.getDepartment(), "labelNm");


That saves me the work of having to put Department into it's own seperate bean first.

[Eric Clayberg]

We don't plan to supported binding to nested attributes until the Eclipse DB API supports that directly. See the following for more detail...

https://bugs.eclipse.org/bugs/show_bug.cgi?id=195222

The approach you are suggesting:

Code: Select all

IObservableValue boProjMgrIdObserveValue = BeansObservables.observeValue(employee.getDepartment(), "labelNm");

is fragile and generaly not what you want. In your example, you are binding directly to a child object or the employee object. If the employee object later changes, you will stil be bound ot the old department object rather than the new department object held by the employee.

In the future, the Eclipse DB API will likely support something like the following:

Code: Select all

IObservableValue boProjMgrIdObserveValue = BeansObservables.observeValue(employee, "department.labelNm");

This will allow for nested bindings that will correctly update as the main object changes.

[urferr]

With 3.5 this works now when using Properties-API):

IObservableValue v = BeanProperties.value("address.street").observe(person);


Will this kind of databinding made available in SWTDesigner in the near future? As i read in the jface newsgroup it should also work with tables and trees

regards
Reto

[Eric Clayberg]

With 3.5 this works now when using Properties-API):
IObservableValue v = BeanProperties.value("address.street").observe(person);
Will this kind of databinding made available in SWTDesigner in the near future?

Yes. That style will be fully supported next week when Eclipse 3.5 is formally released.