PlantUML uses Graphviz for its graph visualization. Thus the rendering itself is done automatically for you - that it one of the biggest advantages of using PlantUML.
...and also sometimes one of the biggest disadvantages, if the rendering is not what the user intended.
For this reason, C4-PlantUML also comes with some layout options.
With the two macros LAYOUT_TOP_DOWN()
and LAYOUT_LEFT_RIGHT()
it is possible to easily change the flow visualization of the diagram. LAYOUT_TOP_DOWN()
is the default.
@startuml LAYOUT_TOP_DOWN Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
/' Not needed because this is the default '/
LAYOUT_TOP_DOWN()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml
LAYOUT_LEFT_RIGHT()
rotates the flow visualization to from Left to Right and directed relations like Rel_Left()
, Rel_Right()
, Rel_Up()
and Rel_Down()
are rotated too.
@startuml LAYOUT_LEFT_RIGHT Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
LAYOUT_LEFT_RIGHT()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml
LAYOUT_LANDSCAPE()
rotates the default flow visualization to from Left to Right like LAYOUT_LEFT_RIGHT()
additional directed relations like Rel_Left(), Rel_Right(), Rel_Up() and Rel_Down() are not rotated anymore.
@startuml LAYOUT_LANDSCAPE Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
LAYOUT_LANDSCAPE()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
System(S,"S")
System(SU,"S Up")
System(SD,"S Down")
System(SL,"S Left")
System(SR,"S Right")
Rel_Up(S, SU, "Up")
Rel_Down(S, SD, "Down")
Rel_Left(S, SL, "Left")
Rel_Right(S, SR, "Right")
SHOW_LEGEND()
@enduml
Colors can help to add additional information or simply to make the diagram more aesthetically pleasing. It can also help to save some space.
All of that is the reason, C4-PlantUML uses colors and prefer also to enable a layout without <<stereotypes>>
and with a legend.
This can be enabled with LAYOUT_WITH_LEGEND()
.
@startuml LAYOUT_WITH_LEGEND Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
LAYOUT_WITH_LEGEND()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml
Instead of a static legend (activated with LAYOUT_WITH_LEGEND()
) a calculated legend can be activated with SHOW_LEGEND(?hideStereotype)
.
The calculated legend has following differences:
- only relevant elements are listed
- custom tags/styles are supported
- stereotypes can remain visible (with
SHOW_LEGEND(false)
) SHOW_LEGEND()
has to be last call in the diagram
@startuml SHOW_LEGEND Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
SHOW_LEGEND()
@enduml
LAYOUT_WITH_LEGEND()
and SHOW_LEGEND(?hideStereotype)` adds the legend at the bottom right of the picture like below and additional whitespace is created.
@startuml Layout With Whitespace Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
Person(a, "Person A")
Container(b, "Container B", "techn")
System(c, "System C")
Container(d, "Container D", "techn")
Container_Ext(e, "Ext. Container E", "techn")
Rel_R(a, b, "calls")
Rel_D(b, c, "uses")
Rel_D(c, d, "uses")
Rel_R(d, e, "updates")
SHOW_LEGEND()
@enduml
Therefore a floating legend can be added via SHOW_FLOATING_LEGEND(), positioned with Lay_Distance() and existing whitespace is reused like below.
- `SHOW_FLOATING_LEGEND(?alias, ?hideStereotype): shows the legend in the drawing area
LEGEND()
: is the default alias of the created floating legend and can be used in Lay_Distance() call
@startuml Compact Legend Layout Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
Person(a, "Person A")
Container(b, "Container B", "techn")
System(c, "System C")
Container(d, "Container D", "techn")
Container_Ext(e, "Ext. Container E", "techn")
Rel_R(a, b, "calls")
Rel_D(b, c, "uses")
Rel_D(c, d, "uses")
Rel_R(d, e, "updates")
SHOW_FLOATING_LEGEND()
Lay_Distance(LEGEND(), e, 1)
@enduml
LAYOUT_AS_SKETCH() and SET_SKETCH_STYLE(?bgColor, ?fontColor, ?warningColor, ?fontName, ?footerWarning, ?footerText)
C4-PlantUML can be especially helpful during up-front design sessions. One thing which is often ignored is the fact, that these software architecture sketches are just sketches.
Without any proof
- if they are technically possible
- if they can fulfill all requirements
- if they keep what they promise
More often these sketches are used by many people as facts and are manifested into their documentations.
With LAYOUT_AS_SKETCH()
you can make a difference.
@startuml LAYOUT_AS_SKETCH Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
LAYOUT_AS_SKETCH()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml
Additional styles and the footer text can be changed with SET_SKETCH_STYLE():
SET_SKETCH_STYLE(?bgColor, ?fontColor, ?warningColor, ?fontName, ?footerWarning, ?footerText)
: Enables the modification of differnt sketch styles and footer.
The possible font name(s) depend on the output format (e.g. PNG uses fonts which are installed on the server and SVG fonts have to be installed on the client). Additional is it possible to define comma separated fall back fonts (if the diagrams are exported as SVG. Atm PNG does not support fallback fonts based on a PlantUML bug, but this could be fixed in one of the following versions)
@startuml LAYOUT_AS_SKETCH Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
SET_SKETCH_STYLE($bgColor="lightblue", $fontColor="darkblue", $warningColor="darkred", $footerWarning="Sketch", $footerText="Created for discussion")
' PNG with font jlm_cmmi10 (typically another font is used)
' SET_SKETCH_STYLE($fontName="jlm_cmmi10")
' SVG with fallback fonts MS Gothic,Comic Sans MS, Comic Sans, Chalkboard SE, Comic Neue, cursive, sans-serif (typically without "MS Gothic")
SET_SKETCH_STYLE($fontName="MS Gothic,Comic Sans MS,Comic Sans,Chalkboard SE,Comic Neue,cursive,sans-serif")
LAYOUT_AS_SKETCH()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml
PNG with font jlm_cmmi10
SVG with fallback fonts MS Gothic,Comic Sans MS,Comic Sans,Chalkboard SE,Comic Neue,cursive,sans-serif
All available (PNG) fonts can be displayed with
@startuml
listfonts
@enduml
To enable a layout without <<stereotypes>>
and legend.
This can be enabled with HIDE_STEREOTYPE()
.
@startuml HIDE_STEREOTYPE Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
HIDE_STEREOTYPE()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml
With the macros HIDE_PERSON_SPRITE()
, SHOW_PERSON_SPRITE()
and SHOW_PERSON_PORTRAIT()
it is possible to change the person related default sprite or person layout itself. SHOW_PERSON_SPRITE()
is the default.
- HIDE_PERSON_SPRITE(): deactivates the default sprite
- SHOW_PERSON_SPRITE(): activates the default sprite "person"
- SHOW_PERSON_SPRITE($sprite): activates a specific sprite as default sprite
- SHOW_PERSON_PORTRAIT(): activates portrait instead of a rectangle
- SHOW_PERSON_OUTLINE(): activates person outline instead of a rectangle
"person" and "person2" are predefined sprites which can be used as default sprite too.
@startuml predefined sprites Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
Person(userA, "User A", "with predefined sprite person", "person")
Person(userB, "User B", "with predefined sprite person2", "person2")
@enduml
Using HIDE_PERSON_SPRITE()
@startuml HIDE_PERSON_SPRITE Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
HIDE_PERSON_SPRITE()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml
Using SHOW_PERSON_SPRITE()
@startuml SHOW_PERSON_SPRITE Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
/' Not needed because this is the default with sprite "person" '/
SHOW_PERSON_SPRITE()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml
Using SHOW_PERSON_SPRITE(sprite)
@startuml SHOW_PERSON_SPRITE(sprite) Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
!define osaPuml https://raw.githubusercontent.com/Crashedmind/PlantUML-opensecurityarchitecture2-icons/master
!include osaPuml/Common.puml
!include osaPuml/User/all.puml
SHOW_PERSON_SPRITE("osa_user_green_architect")
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml
Using SHOW_PERSON_PORTRAIT()
@startuml SHOW_PERSON_PORTRAIT() Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
SHOW_PERSON_PORTRAIT()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
' if a person is combined with a sprite then the rectangle layout is used again
Person(person, "Person with sprite", $sprite="person2")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml
Using SHOW_PERSON_OUTLINE()
This call requires PlantUML version >= v1.2021.4!
@startuml SHOW_PERSON_OUTLINE() Sample
!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
SHOW_PERSON_OUTLINE()
Person(admin, "Administrator")
System_Boundary(c1, 'Sample') {
Container(web_app, "Web Application", "C#, ASP.NET Core 2.1 MVC", "Allows users to compare multiple Twitter timelines")
}
System(twitter, "Twitter")
' if a person is combined with a sprite then the rectangle layout is used again
Person(person, "Person with sprite", $sprite="person2")
Rel(admin, web_app, "Uses", "HTTPS")
Rel(web_app, twitter, "Gets tweets from", "HTTPS")
@enduml