[9] Review request: 8178015: Clarify requirement for app modules to export/open packages to javafx modules

[Kevin Rushforth]

Mandy Chung wrote:
>> On Apr 18, 2017, at 12:48 PM, Kevin Rushforth <kevin.rushforth at oracle.com> wrote:
>>
>>
>>
>> Alan Bateman wrote:
>>     
>>> On 18/04/2017 19:19, Kevin Rushforth wrote:
>>>       
>>>> Good suggestion. Here is an updated webrev with Mandy's suggestion and yours:
>>>>
>>>> http://cr.openjdk.java.net/~kcr/8178015/webrev.01/
>>>>
>>>> -- Kevin
>>>>         
>>> This looks mostly okay.
>>>
>>> I guess for FXML then I assume that the annotated member could be public, in which case the package just needs to be exported (no need to open).
>>>       
>> Yes, it could be, but the more typical use of the annotation is on non-public members, so that was why I chose that as the example.
>>     
>
> I have the same comment as Alan.  The example in the javadoc may be perceived as a recommendation.  We should probably recommend the annotated member be moved to public and encapsulated in its module, just exports it to javafx.fxml to use.  
>   

For the use of the FXML annotation, that is exactly the recommendation. 
If you want the FXMLLoader to modify a public member in a public class, 
you don't need the annotation at all (although I guess it can still be 
used as useful documentation).

In the longer "Introduction to FXML" doc, which is included with the API 
docs and linked from the javafx.fxml package description, the only 
examples we give of using the @FXML annotation are for non-public 
members. See:

http://download.java.net/java/jdk9/jfxdocs/javafx/fxml/doc-files/introduction_to_fxml.html#fxml_annotation

Specifically, the description of the FXML annotation says:

    However, for developers who prefer more restricted visibility for
    controller fields or handler methods, the javafx.fxml.FXML
    annotation can be used. This annotation marks a protected or private
    class member as accessible to FXML.


For consistency, it seems best to show the example in the FXML javadocs 
as an example of using "opens" since that is what would be needed for 
the typical use case, such as those we document elsewhere.

-- Kevin


> Mandy