Constructor annotation

Stephen F Northover steve.x.northover at
Wed Oct 16 10:27:50 PDT 2013


Perhaps @NamedArg is shorter and makes the code more readable?

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On 2013-10-16 1:25 PM, Richard Bair wrote:
> Looks good to me.
>> On Oct 16, 2013, at 10:02 AM, Stephen F Northover <steve.x.northover at> wrote:
>> It seems we are settling on @NamedArgument ... anybody disagree strongly?
>> Steve
>>> On 2013-10-16 11:45 AM, Richard Bair wrote:
>>> Ya that works too.
>>>> On Oct 16, 2013, at 8:41 AM, Eva Krejcirova <eva.krejcirova at> wrote:
>>>> Good point!
>>>> In FX sources, we already use the @Default annotation which was used by annotation processor when generating the builders. Because of this, it has source retention policy, so it cannot be used by FXMLLoader. I was thinking about promoting this to runtime annotation but maybe your solution is better.
>>>> We should solve this for FX8 otherwise the FXMLLoader will behave differently from how the generated builders behaved.
>>>> Eva
>>>>> On 16.10.2013 17:24, Tom Schindl wrote:
>>>>> One thing that just came to my mind is that maybe also need a way to
>>>>> define the default value to be used, with a builder I could e.g. define
>>>>> that the default for fields are different from their real native default.
>>>>> class MyBuilder {
>>>>>    private boolean a = true;
>>>>>    private int x = -1;
>>>>>    private Insets i = new Insets(10);
>>>>> }
>>>>> If we want to have a full replacement for builders the annotation must
>>>>> have the possibility define this (in future).
>>>>> public @interface NamedArgument {
>>>>>    String value();
>>>>>    String defaultValue();
>>>>>    Class<Converter> converterClass();
>>>>> }
>>>>> If no converterClass is given we'd have to do our best to auto-convert
>>>>> the String. I don't want to say that we should implement the default
>>>>> value definition in FX8 but it would feel more natural with an
>>>>> annotation per argument.
>>>>> Tom
>>>>>> On 16.10.13 17:12, Tom Schindl wrote:
>>>>>> To me the JavaBean solution with one annotation looks error prone, does
>>>>>> anybody know why they did not use an annotation per field?
>>>>>> Tom
>>>>>>> On 16.10.13 16:58, Stephen F Northover wrote:
>>>>>>> +1 for base.  Should we not follow closely what Java Beans is doing for
>>>>>>> consistency?  I realize that we can't have the reference.
>>>>>>> Steve
>>>>>>>> On 2013-10-16 10:53 AM, Kevin Rushforth wrote:
>>>>>>>> Not to mention Tom's point that it can't be in the fxml module without
>>>>>>>> created unwanted (and circular) module dependencies. Seems like it
>>>>>>>> needs to be in the "base" module then, right?
>>>>>>>> -- Kevin
>>>>>>>> Richard Bair wrote:
>>>>>>>>> +1 this is my preference. It is useful for things other than FXML,
>>>>>>>>> and should be considered part of our javafx.beans API.
>>>>>>>>>> On Oct 16, 2013, at 4:20 AM, Tom Schindl
>>>>>>>>>> <tom.schindl at> wrote:
>>>>>>>>>>> On 16.10.13 11:22, Eva Krejcirova wrote:
>>>>>>>>>>> Hi All,
>>>>>>>>>>> when we retired builders, we caused a problem for FXML which doesn't
>>>>>>>>>>> have a way to create classes without default constructors. Back
>>>>>>>>>>> then we
>>>>>>>>>>> decided to use an annotation for this but never actually got to
>>>>>>>>>>> implement it and we need to fix this for FX8. I am in the process of
>>>>>>>>>>> adding this functionality to FXMLLoader but we need to decide how the
>>>>>>>>>>> annotation will look like and I could use some help with this.
>>>>>>>>>>> We cannot use already existing ConstructorProperties for this, because
>>>>>>>>>>> it's java.beans package and we don't want to create to dependency on
>>>>>>>>>>> this package in JavaFX, so we need to introduce a new annotation.
>>>>>>>>>>> We have two options:
>>>>>>>>>>> 1. Annotate the whole constructor:
>>>>>>>>>>> e.g.
>>>>>>>>>>>     @ConstructorArguments({"a", "b", "list"})
>>>>>>>>>>>     public ImmutableClass(int a, int b, Integer... list)
>>>>>>>>>>> 2. Annotate the arguments:
>>>>>>>>>>> e.g.
>>>>>>>>>>>     public ImmutableClass(@FXMLArgument("a") int a,
>>>>>>>>>>> @FXMLArgument("b")int b, @FXMLArgument("list")Integer... list)
>>>>>>>>>>> Which option do you like more and how should the annotation be named?
>>>>>>>>>> Option 2, but does it really have to hold FXML in the annotation name?
>>>>>>>>>> Where would you put the annotation? I think it should NOT be in the
>>>>>>>>>> FXML-Package-Namespace because the core should NOT depend on FXML!
>>>>>>>>>> I'd go with @Argument or simply @NamedArgument (@Named is already used
>>>>>>>>>> by javax.inject)
>>>>>>>>>> Tom

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