Add RequestPredicate Visitor to WebFlux.fn [SPR-17322]

[spring-projects-issues]

Arjen Poutsma opened SPR-17322 and commented

Next to the RouterFunctions.Visitor, we should have a RequestPredicates.Visitor, which allows one to iterate over the matching predicates.

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Referenced from: commits b1b28d4, 88cb126

[spring-projects-issues]

Arjen Poutsma commented

I've created a prototype for this, and I would like to make sure that it's adequate before I commit it to master.

Sébastien Deleuze, could you take a look at this branch, and see if it does everything you need? The changes are here: poutsma@c6ed61d
As you can see, I reimplemented the ToStringVisitor to use the new predicate visitor, instead of relying on the predicate's toString.

[spring-projects-issues]

Sébastien Deleuze commented

Hey, sorry I was not available to answer on time before 5.1.1 since I was traveling, but I like the approach you took and I think it fits the need.
Since we have some time before 5.1.2, I am going to ask on Spring Fu side if we can draft something that would use your branch to give you more concrete feedback before 5.1.2.

[spring-projects-issues]

tgirard12 commented

This new predicate is very useful when we want to know all the RequestPredicate for all the routes. We can use it for automatic documentation for exemple.

I used both Router and Request visitor to get all the informations I want.

When I play with it in Kotlin with the RouterFunctionDsl, I could not used the visitor only for one route because  GET("/foo") { ok() } doesn't return the PathPatternPredicate but Unit.

 

 

[spring-projects-issues]

Sébastien Deleuze commented

tgirard12 Do you think there is something I should fix in RouterFunctionDsl to make it work?

[spring-projects-issues]

tgirard12 commented

It's work all ready, but the syntax is not very clean : (GET("/bar").apply { accept(visitor) }) { handle(it) }.
GET("/foo", ::handle) could return the RequestPredicate but in this case, we could add predicates after invoking the ::handle function. I think it's not a good thing.

[spring-projects-issues]

Sébastien Deleuze commented

Arjen Poutsma Do you think there could be a way to configure in more centralized and less intrusive fashion the request predicates, in order to be able to generate the documentation without modifying user routes?

[spring-projects-issues]

Sébastien Deleuze commented

tgirard12 Unless I am mistaken, It seems already possible to add a visitor in a non intrusive way (which is the original goal of this issue) with the Kotlin DSL, since it generates a RouterFunction without modifying user routes, like it is with Java DSL with a visitor that implement both RouterFunctions.Visitor and RequestPredicates.Visitor, see this test and this visitor.

So I am ok for inclusion in 5.1.3.

[spring-projects-issues]

Arjen Poutsma commented

Fixed in 

Add RequestPredicate Visitor to WebFlux.fn