This is still under construction. You can propose new features if you need some.
Declaring participant
You declare participant using the following keywords, depending on how you want them to be drawn.
concise: A simplified signal designed to show the movement of data (great for messages).
robust: A complex line signal designed to show the transition from one state to another (can have many states).
clock: A 'clocked' signal that repeatedly transitions from high to low
binary: A specific signal restricted to only 2 states (binary).
You define state change using the @ notation, and the is verb.
@startuml
robust "Web Browser" as WB
concise "Web User" as WU
@0
WU is Idle
WB is Idle
@100
WU is Waiting
WB is Processing
@300
WB is Waiting
@enduml
Binary and Clock
It's also possible to have binary and clock signal, using the following keywords:
binary
clock
@startuml
clock clk with period 1
binary "Enable" as EN
@0
EN is low
@5
EN is high
@10
EN is low
@enduml
Adding message
You can add message using the following syntax.
@startuml
robust "Web Browser" as WB
concise "Web User" as WU
@0
WU is Idle
WB is Idle
@100
WU -> WB : URL
WU is Waiting
WB is Processing
@300
WB is Waiting
@enduml
Relative time
It is possible to use relative time with @.
@startuml
robust "DNS Resolver" as DNS
robust "Web Browser" as WB
concise "Web User" as WU
@0
WU is Idle
WB is Idle
DNS is Idle
@+100
WU -> WB : URL
WU is Waiting
WB is Processing
@+200
WB is Waiting
WB -> DNS@+50 : Resolve URL
@+100
DNS is Processing
@+300
DNS is Idle
@enduml
Anchor Points
Instead of using absolute or relative time on an absolute time you can define a time as an anchor point by using the as keyword and starting the name with a :.
@XX as :<anchor point name>
@startuml
clock clk with period 1
binary "enable" as EN
concise "dataBus" as db
@0 as :start
@5 as :en_high
@10 as :en_low
@:start
EN is low
db is "0x0000"
@:en_high
EN is high
@:en_low
EN is low
@:en_high-2
db is "0xf23a"
@:en_high+6
db is "0x0000"
@enduml
Participant oriented
Rather than declare the diagram in chronological order, you can define it by participant.
@startuml
robust "Web Browser" as WB
concise "Web User" as WU
@WB
0 is idle
+200 is Proc.
+100 is Waiting
@WU
0 is Waiting
+500 is ok
@enduml
Setting scale
You can also set a specific scale.
@startuml
concise "Web User" as WU
scale 100 as 50 pixels
@WU
0 is Waiting
+500 is ok
@enduml
Initial state
You can also define an inital state.
@startuml
robust "Web Browser" as WB
concise "Web User" as WU
WB is Initializing
WU is Absent
@WB
0 is idle
+200 is Processing
+100 is Waiting
@WU
0 is Waiting
+500 is ok
@enduml
Intricated state
A signal could be in some undefined state.
@startuml
robust "Signal1" as S1
robust "Signal2" as S2
S1 has 0,1,2,hello
S2 has 0,1,2
@0
S1 is 0
S2 is 0
@100
S1 is {0,1} #SlateGrey
S2 is {0,1}
@200
S1 is 1
S2 is 0
@300
S1 is hello
S2 is {0,2}
@enduml
Hidden state
It is also possible to hide some state.
@startuml
concise "Web User" as WU
@0
WU is {-}
@100
WU is A1
@200
WU is {-}
@300
WU is {hidden}
@400
WU is A3
@500
WU is {-}
@enduml
Hide time axis
It is possible to hide time axis.
@startuml
hide time-axis
concise "Web User" as WU
WU is Absent
@WU
0 is Waiting
+500 is ok
@enduml
Using Time and Date
It is possible to use time or date.
@startuml
robust "Web Browser" as WB
concise "Web User" as WU
@2019/07/02
WU is Idle
WB is Idle
@2019/07/04
WU is Waiting : some note
WB is Processing : some other note
@2019/07/05
WB is Waiting
@enduml
@startuml
robust "Web Browser" as WB
concise "Web User" as WU
@1:15:00
WU is Idle
WB is Idle
@1:16:30
WU is Waiting : some note
WB is Processing : some other note
@1:17:30
WB is Waiting
@enduml
Adding constraint
It is possible to display time constraints on the diagrams.
@startuml
robust "Web Browser" as WB
concise "Web User" as WU
WB is Initializing
WU is Absent
@WB
0 is idle
+200 is Processing
+100 is Waiting
WB@0 <-> @50 : {50 ms lag}
@WU
0 is Waiting
+500 is ok
@200 <-> @+150 : {150 ms}
@enduml
Highlighted period
You can higlight a part of diagram.
@startuml
robust "Web Browser" as WB
concise "Web User" as WU
@0
WU is Idle
WB is Idle
@100
WU -> WB : URL
WU is Waiting #LightCyan;line:Aqua
@200
WB is Proc.
@300
WU -> WB@350 : URL2
WB is Waiting
@+200
WU is ok
@+200
WB is Idle
highlight 200 to 450 #Gold;line:DimGrey : This is my caption
@enduml
Adding texts
You can optionally add a title, a header, a footer, a legend and a caption:
@startuml
Title This is my title
header: some header
footer: some footer
legend
Some legend
end legend
caption some caption
robust "Web Browser" as WB
concise "Web User" as WU
@0
WU is Idle
WB is Idle
@100
WU is Waiting
WB is Processing
@300
WB is Waiting
@enduml
@startuml
concise "Client" as Client
concise "Server" as Server
concise "Response freshness" as Cache
Server is idle
Client is idle
@Client
0 is send
Client -> Server@+25 : GET
+25 is await
+75 is recv
+25 is idle
+25 is send
Client -> Server@+25 : GET\nIf-Modified-Since: 150
+25 is await
+50 is recv
+25 is idle
@100 <-> @275 : no need to re-request from server
@Server
25 is recv
+25 is work
+25 is send
Server -> Client@+25 : 200 OK\nExpires: 275
+25 is idle
+75 is recv
+25 is send
Server -> Client@+25 : 304 Not Modified
+25 is idle
@Cache
75 is fresh
+200 is stale
@enduml
Digital Example
@startuml
scale 5 as 150 pixels
clock clk with period 1
binary "enable" as en
binary "R/W" as rw
binary "data Valid" as dv
concise "dataBus" as db
concise "address bus" as addr
@6 as :write_beg
@10 as :write_end
@15 as :read_beg
@19 as :read_end
@0
en is low
db is "0x0"
addr is "0x03f"
rw is low
dv is 0
@:write_beg-3
en is high
@:write_beg-2
db is "0xDEADBEEF"
@:write_beg-1
dv is 1
@:write_beg
rw is high
@:write_end
rw is low
dv is low
@:write_end+1
rw is low
db is "0x0"
addr is "0x23"
@12
dv is high
@13
db is "0xFFFF"
@20
en is low
dv is low
@21
db is "0x0"
highlight :write_beg to :write_end #Gold:Write
highlight :read_beg to :read_end #lightBlue:Read
db@:write_beg-1 <-> @:write_end : setup time
db@:write_beg-1 -> addr@:write_end+1 : hold
@enduml
@startuml
concise "LR" as LR
concise "ST" as ST
LR is AtPlace #palegreen
ST is AtLoad #gray
@LR
0 is Lowering
100 is Lowered #pink
350 is Releasing
@ST
200 is Moving
@enduml