Please provide a way to add an action to the repeat loop start instead of a condition

Question

I'd like to replace the empty diamond at the start of a repeat loop with an action.

In the following example, if the "data is invalid", I just want to "prompt for data" again:

start
repeat
    :prompt for data;
repeat while (data is valid) is (no) not (yes)
:use data;
stop

I looked in past questions and discovered a few things, but nothing about this particular case. It seems like it would make the diagram a little smaller.

Maybe something like repeat (prompt for data)

I can sort of do it with a while loop, but it would not look as nice.

Thank you!

Answer 1

Fortunately, this is a part of code we are currently working on.

So in last beta (beta14):
https://www.dropbox.com/s/koo42q3d9gxw288/plantuml.jar?dl=0

You can now have:

@startuml
start
repeat :foo as starting label;
  :read data;
  :generate diagrams;
backward:This is backward;
repeat while (more data?)
stop
@enduml

This has not been tested very widely, so feedback welcome!
Thanks for your idea!
 

Comments

Thanks,

I was hoping I could have the starting label be an activity instead of a diamond (in my example, I am prompting for data until the data is valid, the start of my loop is not a test, so a round box seems more appropriate).

backward looks like a nice addition, will it be possible to have several activities in the backward "chain" (ah, so many requests! although this is more of a question really.)

Thanks!
Christophe

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Ok, we've removed the diamond in last beta16
https://www.dropbox.com/s/koo42q3d9gxw288/plantuml.jar?dl=0

About backward, adding several activities in the backward chain is not too difficult to implement, so we will probably do it latter.

Welcome still welcome :-)

---

Impressive, thank you!!
Christophe

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Is it possible to specify a color code in the repeat and backward definitions? Parsing-wise, it seems feasible to manage:

repeat
    #AAA:Loopback activity;
    floating note left: Note for loopback activity

    :Some internal activity;

backward
    #AFF:Backward activity 1;
    floating note right: Note for backward activity 1
    #AFF:Backward activity 2;
    floating note right: Note for backward activity 2

repeat while (Success?) is (No)

where the first activity after the start of the repeat clause and its associated note (for example) define the loopback activity.