PlantUml define relative position of components

Question

I'm actually trying to generate a component diagram with PlantUml. Is it possible to define the relative position of the different components? What I want to define is: ComponentB is left from ComponentA. ComponentC is below ComponentA, ...

Rajab

Does this answer your question? How to align blocks in PlantUML class diagrams? – Head

Answer 1

A typical approach is to mark a line as hidden.

One thing to keep in mind is that hidden is only supported for left-to-right ->, and top-to-bottom --> lines, so you need to place the left and right side accordingly (syntax X <[hidden]- Y doesn't seem to be supported).

@startuml
class ComponentA

ComponentB -[hidden]> ComponentA
ComponentA -[hidden]-> ComponentC
@enduml

See also How to correct PlantUML Line Path for more positioning tips.

Intreat

>is only supported for left-to-right ->, and top-to-bottom --> lines TIL. That functionality isn't mentioned in the documentation! – Creditable

@campisano has mentioned a link in above comment. Which has information on, using together keyword to group some classes together : the layout engine will try to group them (as if they were in the same package). – Cere

Answer 2

You can follow guidelines from here: Layout of grouping component

In general when you write connections like -> you just have to know that there is special notation for right arrow, left arrow, bottom arrow, top arrow: This has special meaning for plantUml:

 -l->
 -r->
 -u->
 -d->

It means to place arrow on the left or right or up or down if possible.

Lets imagine this diagram:

@startuml
node "My system" {
  [A] -> [B]
  [C] -> [B]
}
@enduml

This looks horrible, you can fix this by directing PlanUml with arrow directions.

@startuml
node "My system" {
  [A] -d-> [B]
  [C] -r-> [B]
}
@enduml

Will generate this:

Clarettaclarette

Why is this not the accepted answer this is perfect, unless you can't combine [hidden] and -u|d|l|r-> – Criseldacrisey

You can combine those. But it's finicky (as everything in organizing PlantUML states seems to be). STATE0 -up[hidden]-> STATE1: TEST does work but may be different with only one - as STATE0 -up[hidden]> STATE1: TEST. – Dispraise

-[hidden]right-> seems valid, but does not do what I want yet.. – Crosswind