Unable to link between fields in different namespaces

Question

Hi,

I'm having trouble creating a relation between two fields on classes from different namespaces. I expect the following to create a relation from c -> d and d -> c but it does not.

@startuml
namespace a.b {
  class C {
    c
  }
  C::c o-- e.f.D::d
}
class e.f.D {
  d
}
e.f.D::d o-- a.b.C::c
@enduml

Instead it looks like:

 ,-.   ,-.
 |C|   |D|
 |-|   |-|
 |c|   |d|
 `-'   `-'
   |
   |
,----.
|D::d|
|----|
`----'
   |
,----.
|C::c|
|----|
`----'

(namespaces missing from ASCII output)

Cheers

Comments

Aside from you trying to forward link to a class that hasn't been defined yet - which I'm not sure is intended to be supported - there does seem to be a confliction between namespaces and qualified fields.

By changing the namespace to a package, moving your forward link to the end, and changing the namespace separator to avoid both "." and "::", I was able to achieve this:

@startuml
set namespaceSeparator $$
package a.b {
  class C {
    c
  }

}
class e.f.D {
  d
}
a.b$$C::c o-- e.f.D::d
e.f.D::d o-- a.b$$C::c
@enduml

(could use "skinparam Linetype ortho" or "left to right direction" to improve the look).

Is that what you think your diagram should look like?  Or should D be in a group "e.f" ?

But I agree that I shouldn't have had to do some of that; and there does appear to be a bug.

---

Thanks for the answer. 

trying to forward link to a class that hasn't been defined yet - which I'm not sure is intended to be supported

 A similar effect occurs if you have an extends clause before defining the parent type (or don't define it at all). You can also define a class multiple times and they get combined. I really like this feature / unintended side effect, it has greatly simplified things for me (I'm writing a diagram generator).

The problem with using packages is that my class names are not globally unique.

Is that what you think your diagram should look like?  Or should D be in a group "e.f" ?

Yeah, D should be in a namespace "e.f".

---

See "Issue about Namespace and Package" at http://alphadoc.plantuml.com/doc/dokuwiki/en/poll-about-package-and-namespace#2ou4k28pt3ukk5v9fq2d

The code below produces a diagram identical to that of Martin

@startuml
!pragma useNewPackage
set separator .
class e.f.D {
  d
}
namespace a.b {
  class C {
    c
  }
  C::c o-- e.f.D::d
}
e.f.D::d o-- a.b.C::c
@enduml

---

Brilliant!  (I had always assumed that webpage was historical.)

Answer 1

Thanks to Poi for pointing out the "useNewPackage" beta feature!

I've made it work with the OP's example (enhanced with the name clash that the OP needed to be handled).

I even managed to enable the forward use of a field name - I had to first autovivicate the e.f.C class using a hidden link.

@startuml

!pragma useNewPackage
set separator .

namespace a.b {
  class C {
    c
  }
  C::c o-[hidden]- e.f.C
  C::c o-- e.f.C::c
}

class e.f.C {
  c
}

e.f.C::c o-- a.b.C::c

@enduml