Sorry for late reply. Please see my comments inline.
On Mon, Apr 9, 2018 at 4:14 PM, Daniel Dekany <[email protected]> wrote:
> Monday, April 9, 2018, 8:34:27 PM, Woonsan Ko wrote:
>
>> Hi,
>>
>> While trying to implement directives to replace Spring MVC select,
>> options and option tags [1], I'm wondering what is the best to nest
>> options or option directive inside form directive.
>
> Or, you mean the "select" directive?
>
>> One straightforward option is:
>>
>> <@form.select 'user.favoriteSport'; form>
>> <@option form value="NONE" label="--- Select ---" />
>> <@options form items=sports />
>> </@form>
>>
>> As we don't have something like
>> javax.servlet.jsp.tagext.TagSupport#findAncestorWithClass(Tag, Class)
>
> Yeah, and we should have that. This is something that's missing from
> FM2 for a long time too... it's in my "most frequently missed
> features" FM2 TODO list. Maybe in 2.3.29.
>
>> (bottom to top), we can pass the form directive model to the nested
>> content like org.apache.freemarker.spring.model.BindDirective does
>> already (top to bottom).
>
> No way, that's way too awkward for the user (especially if you
> consider factoring out <@option ... />-s into macros). For now you
> should just use Environment.getCustomState(CustomStateKey) to maintain
> some state object where you keep track of the current context. (The
> main problem with that feature is that there's no template language
> feature to access it. Like you can't write two macros that exchange
> information through that, purely in the template language. But in your
> case that's not a problem, as you implement everything in Java.)
I want to make the select directive model accessible from a nested
options or option directive model. So I was thinking of something like
the following in the select directive:
// create a custom state key to return this
final CustomStateKey<SelectTemplateDirectiveModel>
selectCustomStateKey = new
CustomStateKey<SelectTemplateDirectiveModel>() {
@Override
protected SelectTemplateDirectiveModel create() {
return SelectTemplateDirectiveModel.this;
}
};
// pass the custom state key
env.getCustomState(selectCustomStateKey);
// execute nested content such as options or option
callPlace.executeNestedContent(null, out, env);
// snip
// write output...
Question is, how can I retrieve the selectCustomStateKey in the nested
option(s) directive?
Environment#getCustomState(CustomStateKey<T>) requires that the nested
directive should have the CustomStateKey instance already somehow. I
wonder how to do that easily without any hacky solutions such as
thread local. servlet request attributes could be the last resort, but
doesn't sound good to me either.
Could you shed a light here?
Regards,
Woonsan
>
>> So, developers are needed to pass it along like the above example,
>> unless it is as simple as one-liner like the following:
>>
>> <@form.select 'user.favoriteSport' items=sports />
>>
>> Does it sounds good? Or do you have any better ideas?
>>
>> Regards,
>>
>> Woonsan
>>
>> [1] https://www.mkyong.com/spring-mvc/spring-mvc-dropdown-box-example/
>>
>
> --
> Thanks,
> Daniel Dekany
>
