How to draw sequence diagram and other diagrams using plantuml

A sequence diagram is a type of interaction diagram that shows how processes operate with one another and in what order. It’s a detailed illustration of a use case, showing the interaction between objects and components in sequential order.

Key Concepts

Lifelines: Represent the objects or participants in the interaction. They are depicted as vertical dashed lines.
Messages: Represent the communication between objects. They are depicted as arrows between lifelines.
Activation Bars: Indicate the period an object is active during the interaction.
Fragments: Used for representing complex control structures like loops, conditionals, and parallel processes.

Sequence Diagram Notation

Actors: Represent roles that interact with the system (e.g., user).
Objects/Lifelines: Represent instances of classes or components.
Messages: Include synchronous (solid arrow with filled head) and asynchronous messages (solid arrow with open head).
Return Messages: Represent responses or return values (dashed arrows).
Activation Bars: Vertical rectangles on lifelines indicating the duration an object is active.

Creating a Sequence Diagram

To create a sequence diagram, follow these steps:

Identify the Scenario: Define the specific use case or scenario.
Identify Objects: Determine the objects that participate in the scenario.
Determine Interactions: Identify the sequence of interactions between objects.
Layout Diagram: Place the objects at the top, draw lifelines, and add messages in sequence.

Example: User Login Sequence Diagram

Scenario: User logs into a system

Actors: User
Objects: Login Page, Authentication Service, User Database

Steps

User requests the login page.
User submits login credentials.
Login page sends credentials to the Authentication Service.
Authentication Service queries the User Database.
User Database returns user information.
Authentication Service validates credentials and returns success/failure.
Login page shows success/failure message to the user.

Sequence Diagram Example

Sequence Diagram Fig 1

UML Sequence Diagram Example in PlantUML

Here’s a sequence diagram using PlantUML:

plantuml

@startuml

actor User

participant "Login Page" as LoginPage

participant "Authentication Service" as AuthService

participant "User Database" as UserDB

User -> LoginPage : requests login page

LoginPage -> User : displays login form

User -> LoginPage : submits login form

LoginPage -> AuthService : sends credentials

AuthService -> UserDB : queries user info

UserDB --> AuthService : returns user info

AuthService -> AuthService : validates credentials

AuthService --> LoginPage : returns success/failure

LoginPage --> User : displays result

@enduml

Deep Dive into Sequence Diagram Concepts

Fragments:

alt: Represents alternative flows (if-else conditions).
opt: Represents an optional fragment (similar to a simple if statement).
loop: Represents repeated interaction (looping).
par: Represents parallel execution (concurrent operations).

Synchronous vs Asynchronous Messages:

Synchronous: Sender waits for a response (blocking call). Depicted with a solid arrow and filled head.
Asynchronous: Sender does not wait for a response (non-blocking call). Depicted with a solid arrow and open head.

Lifelines and Activation Bars:

Lifeline: Vertical dashed line representing the object's presence over time.
Activation Bar: Rectangle on the lifeline representing the time period an object is active (performing an action).

Self-Messages:

A message sent from an object to itself, representing recursive calls or self-initiated actions.

Similarly, some other UML Example in PlantUML

A> UML State Diagram Example in PlantUML

Here’s a state diagram using PlantUML:

plantuml

@startuml

'https://plantuml.com/state-diagram

scale 350 width

[*] --> NotShooting

state NotShooting {

[*] --> Idle

Idle --> Configuring : EvConfig

Configuring --> Idle : EvConfig

}

state Configuring {

[*] --> NewValueSelection

NewValueSelection --> NewValuePreview : EvNewValue

NewValuePreview --> NewValueSelection : EvNewValueRejected

NewValuePreview --> NewValueSelection : EvNewValueSaved

state NewValuePreview {

State1 -> State2

}

@enduml

B> UML Gantt Diagram Example in PlantUML

Here’s a gantt diagram using PlantUML:

plantuml

@startgantt

'https://plantuml.com/gantt-diagram

[Prototype design] lasts 13 days and is colored in Lavender/LightBlue

[Test prototype] lasts 9 days and is colored in Coral/Green and starts 3 days after [Prototype design]'s end

[Write tests] lasts 5 days and ends at [Prototype design]'s end

[Hire tests writers] lasts 6 days and ends at [Write tests]'s start

[Init and write tests report] is colored in Coral/Green

[Init and write tests report] starts 1 day before [Test prototype]'s start and ends at [Test prototype]'s end

@endgantt

C> UML Deployment Diagram Example in PlantUML

Here’s a deployment diagram using PlantUML:

plantuml

@startuml

'https://plantuml.com/deployment-diagram

actor actor

actor/ "actor/"

agent agent

artifact artifact

boundary boundary

card card

circle circle

cloud cloud

collections collections

component component

control control

database database

entity entity

file file

folder folder

frame frame

interface interface

label label

node node

package package

queue queue

rectangle rectangle

stack stack

storage storage

usecase usecase

usecase/ "usecase/"

@enduml

example:

@startuml

'https://plantuml.com/deployment-diagram

actor actor

agent agent

cloud cloud

file file

interface interface

actor -> agent

agent -> cloud

cloud -> file

file -> interface

interface -> cloud

@enduml

D> UML Mindmap Diagram Example in PlantUML

Here’s a mindmap diagram using PlantUML:

plantuml

@startmindmap

'https://plantuml.com/mindmap-diagram

caption figure 1

title My super title

* <&flag>Debian

** <&globe>Ubuntu

*** Linux Mint

*** Kubuntu

*** Lubuntu

*** KDE Neon

** <&graph>LMDE

** <&pulse>SolydXK

** <&people>SteamOS

** <&star>Raspbian with a very long name

*** <s>Raspmbc</s> => OSMC

*** <s>Raspyfi</s> => Volumio

header

My super header

endheader

center footer My super footer

legend right

Short

legend

endlegend

@endmindmap

E> UML Use case Diagram Example in PlantUML

Here’s a use case diagram using PlantUML:

plantuml

@startuml

'https://plantuml.com/use-case-diagram

:Main Admin: as Admin

(Use the application) as (Use)

User -> (Start)

User --> (Use)

Admin ---> (Use)

note right of Admin : This is an example.

note right of (Use)

A note can also

be on several lines

end note

note "This note is connected\nto several objects." as N2

(Start) .. N2

N2 .. (Use)

@enduml

F> UML Process Diagram Example in PlantUML

Here’s a process diagram using PlantUML:

plantuml

@startwbs

'https://plantuml.com/wbs-diagram

* Business Process Modelling WBS

** Launch the project

*** Complete Stakeholder Research

*** Initial Implementation Plan

** Design phase

*** Model of AsIs Processes Completed

**** Model of AsIs Processes Completed1

**** Model of AsIs Processes Completed2

*** Measure AsIs performance metrics

*** Identify Quick Wins

** Complete innovate phase

@endwbs

G> UML wireframe Diagram Example in PlantUML

Here’s a wireframe diagram using PlantUML:

plantuml

@startuml

'https://plantuml.com/salt

salt

{

Just plain text

[This is my button]

() Unchecked radio

(X) Checked radio

[] Unchecked box

[X] Checked box

"Enter text here "

^This is a droplist^

}

@enduml

H> UML Component Diagram Example in PlantUML

Here’s a Component diagram using PlantUML:

plantuml

@startuml

'https://plantuml.com/component-diagram

package "Some Group" {

HTTP - [First Component]

[Another Component]

}

node "Other Groups" {

FTP - [Second Component]

[First Component] --> FTP

}

cloud {

[Example 1]

}

database "MySql" {

folder "This is my folder" {

[Folder 3]

}

frame "Foo" {

[Frame 4]

}

[Another Component] --> [Example 1]

[Example 1] --> [Folder 3]

[Folder 3] --> [Frame 4]

@enduml

I> UML Class Diagram Example in PlantUML

Here’s a Class diagram using PlantUML:

plantuml

@startuml

'https://plantuml.com/class-diagram

abstract class AbstractList

abstract AbstractCollection

interface List

interface Collection

List <|-- AbstractList

Collection <|-- AbstractCollection

Collection <|- List

AbstractCollection <|- AbstractList

AbstractList <|-- ArrayList

class ArrayList {

Object[] elementData

size()

}

enum TimeUnit {

DAYS

HOURS

MINUTES

}

@enduml

J> UML Context Diagram Example in PlantUML

Here’s a Context diagram using PlantUML:

plantuml

@startuml

!include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Context.puml

'!include ../../plantuml/C4/v2.2.0/C4_Context.puml

' skinparam linetype polyline

' skinparam linetype ortho

skinparam nodesep 20

skinparam ranksep 50

title "System Context diagram for Display App"

System_Ext(Integrator, "Customer", "Digital")

System_Ext(2sg, "router", "authentication, routing, throttling")

System_Ext(sws, "Web Services\nDisplayService\n(2.1.0)")

System(display, "Display Currency APP", "Framework\n\n/api/display\n")

Rel(Integrator,2sg, "API calls")

Rel(2sg,display, "API calls")

Rel(display,sws, "Downstream WS calls")

SHOW_LEGEND()

@enduml

K> UML Jenkins Diagram Example in PlantUML

Here’s a Jenkins diagram using PlantUML:

plantuml

@startuml

!include <cloudogu/common>

!include <cloudogu/dogus/jenkins>

!include <cloudogu/dogus/cloudogu>

!include <cloudogu/dogus/scm>

!include <cloudogu/dogus/smeagol>

!include <cloudogu/dogus/nexus>

!include <cloudogu/tools/k8s>

node "Cloudogu Ecosystem" <<$cloudogu>> {

DOGU_JENKINS(jenkins, Jenkins) #ffffff

DOGU_SCM(scm, SCM-Manager) #ffffff

DOGU_SMEAGOL(smeagol, Smeagol) #ffffff

DOGU_NEXUS(nexus,Nexus) #ffffff

}

TOOL_K8S(k8s, Kubernetes) #ffffff

actor developer

developer --> smeagol : "Edit Slides"

smeagol -> scm : Push

scm -> jenkins : Trigger

jenkins -> nexus : Deploy

jenkins --> k8s : Deploy

@enduml

L> UML Plugin some other API to create icons diagram using context or container Diagram Example in PlantUML

Here’s a container diagram using PlantUML:

plantuml

Person_Ext(user, "Clients", "Clients who are using OOO service", "users")

Boundary(new, "Customer service using CLOVA AiCall") {

Boundary(legacy, "Legacy customer service"){

System_Ext(cc, "Contact Center", "Contact point, switches customer calls.")

Person_Ext(counselor, "Customer counselors", "Interacts with customers to handle complaints, process orders, and provide information about OOO service.", "contact_phone")

System_Ext(ars, "ARS", "Interacts with customers when counselors are not available.")

Rel(user, cc, "Makes a call")

Rel(cc, counselor, "Connects and forwards a call to")

Rel(cc, ars, "Connects and forwards a call to")

}

System(ccai, "CLOVA AiCall", "Interacts with customers using CLOVA AI tech.")

Rel(cc, ccai, "Connects and forwards a call to")

}

Person_Ext(manager, "Manager", "Makes a decision from statistics provided by CLOVA AiCall", "user_tie")

Rel(manager, ccai, "Retrives statistics from")

@enduml

> UML Math Diagram Example in PlantUML

Here’s a Math diagram using PlantUML:

plantuml

@startuml

:<math>int_0^1f(x)dx</math>;

:<math>x^2+y_1+z_12^34</math>;

note right

Try also

<math>P(y|bb"x") or f(bb"x")+epsilon</math>

end note

@enduml

M> UML English Tense Diagram Example in PlantUML

Here’s a English Tense diagram using PlantUML:

plantuml

@startwbs

'https://plantuml.com/wbs-diagram

*[#green] TENSE

**[#SkyBlue] PRESENT \n---\n auxiliary =>[ Do Verb=>do/does\n Be Verb =>am/is/are\n have=>has/have ]\n model verb=[can, must, may, will, shall] \n \n Wh=>[When =>time,Where =>place, who/whom =>person/people, \n why =>reason,what=>object/idea/action, which=>things] \n Ho=>[How=>manner,How many=>countable, \n How much=>non countable, How long=>time,How far=>distance]

*** Indefinite

**** Affirmative or Positive \n Rule: sub+ verb-1st+e/es\nsub+[modal verb] +verb-1st \n [he/she/name/it => s / es] \nmodel verb=[can, must, may, will, shall]

**** Interrogative \n Rule: Do/Does+sub+ verb-1st ? \n [wh-/Ho-] + [Do/Does]+sub+ verb-1st ? \n [wh-/Ho-] + [modal verb] + sub+ verb-1st ? \n [ I / you / we / they => Do]\n [he/she/name/it =>Does]\n model verb=[can, must, may, will, shall]

**** Negative \n Rule: sub+ [do/does]+not + verb-1st\nsub+[modal verb]+[not] +verb-1st \n [ I / you / we / they => do not ]\n [he/she/name/it =>does not] \nmodel verb=[can, must, may, will, shall]

**** Negative-Interrogative \n Rule: Do/Does+sub+ [not]+ verb-1st ? \n [wh-/Ho-] + [Do/Does]+sub+[not]+ verb-1st ? \n [wh-/Ho-] + [modal verb] + sub+ [not]+verb-1st ? \n [ I / you / we / they => Do]\n [he/she/name/it =>Does]\n model verb=[can, must, may, will, shall]

*** Continuous

**** Affirmative or Positive \n Rule: sub+ [am/is/are]+verb-1st+[ing]\n sub+ [modal verb]+[be]+verb-1st+[ing]\n [I => am]\n[he/she/name/it =>is]\n[you,we,they => are]\nmodel verb=[can, must, may, will, shall]

**** Interrogative \n Rule: [am/is/are]+sub+verb-1st+[ing]?\n[modal verb]+sub+verb-1st+[ing]? \n [I => am]\n[he/she/name/it =>is]\n[you,we,they => are] \nmodel verb=[can, must, may, will, shall]

**** Negative \n Rule: sub+ [am/is/are]+[not]+verb-1st+[ing]\n sub+ [modal verb]+[not]+verb-1st+[ing] \n [I => am]\n[he/she/name/it =>is]\n[you,we,they => are]\nmodel verb=[can, must, may, will, shall]

***[#blue] Perfect

**** Affirmative or Positive \n Rule: sub+ [has/have]+verb-3rd \n[he/she/name/it =>has]\n[I/you/we/they => have]

**** Interrogative \n Rule: [has/have]+sub+verb-3rd ? \n[he/she/name/it =>has]\n[I/you/we/they => have]

**** Negative \n Rule: sub+ [has/have]+[not]+verb-3rd \n[he/she/name/it =>has]\n[you,we,they => have]

*** Perfect Continuous

**** Affirmative or Positive \n Rule: sub+ [has/have]+[been]+verb-1st+[ing] +obj +[since/for]+ time \n[he/she/name/it =>has]\n[I/you/we/they => have]

**** Interrogative \n Rule: [has/have]+sub+[been]+verb-1st+[ing] +obj +[since/for]+ time ? \n[he/she/name/it =>has]\n[I/you/we/they => have]

**** Negative \n Rule: sub+ [has/have]+[not]+[been]+verb-1st+[ing] +obj +[since/for]+ time \n[he/she/name/it =>has]\n[I/you/we/they => have]

**[#yellow] PAST \n---\n auxiliary =>[ Do Verb=>did \n Be Verb =>was/were\n have=>had] \nmodel verb=[should, would, could, might] \n Wh=>[When =>time,Where =>place, who/whom =>person/people, \n why =>reason,what=>object/idea/action, which=>things] \n Ho=>[How=>manner,How many=>countable, \n How much=>non countable, How long=>time,How far=>distance]

***[#green] Indefinite

**** Affirmative or Positive \n Rule: sub+ verb-2nd

**** Interrogative \n Rule: Did+sub+ verb-1st ?

**** Negative \n Rule: sub+ [did not]+verb-1st

*** Continuous

**** Affirmative or Positive \n Rule: sub+ [was/were]+verb-1st+[ing]\n sub+ [modal verb]+[be]+verb-1st+[ing]\n[I/he/she/name/it =>was]\n[you/we/they => were] \nmodel verb=[should, would, could, might]

**** Interrogative \n Rule: [was/were]+sub+verb-1st+[ing]? \n[I/he/she/name/it =>was]\n[you/we/they => were]

**** Negative \n Rule: sub+ [was/were]+[not]+verb-1st+[ing]\n sub+ [modal verb]+[not]+[be]+verb-1st+[ing] \n[I/he/she/name/it =>was]\n[you/we/they => were] \nmodel verb=[should, would, could, might]

***[#blue] Perfect

**** Affirmative or Positive \n Rule: sub+ [had]+verb-3rd +[before/after] + Past Indefinite \n[I/he/she/name/it =>had]\n[you/we/they => had]

**** Interrogative \n Rule: [had]+sub+verb-3rd +[before/after] + Past Indefinite? \n[I/he/she/name/it =>had]\n[you/we/they => had]

**** Negative \n Rule: sub+ [had]+[not]+verb-3rd +[before/after] + Past Indefinite \n[I/he/she/name/it =>had]\n[you,we,they => had]

*** Perfect Continuous

**** Affirmative or Positive \n Rule: sub+ [had]+[bean]+verb-1st+[ing] +[before/after] + Past Indefinite \n[I/he/she/name/it =>had]\n[you/we/they => had]

**** Interrogative \n Rule: [had]+sub+[bean]+verb-1st+[ing] +[before/after] + Past Indefinite? \n[I/he/she/name/it =>had]\n[you/we/they => had]

**** Negative \n Rule: sub+ [had]+[not]+[bean]+verb-1st+[ing] +[before/after] + Past Indefinite \n[I/he/she/name/it =>had]\n[you,we,they => had]

**[#pink] FUTURE \n---\n will/shall \n \n Wh=>[When =>time,Where =>place, who/whom =>person/people, \n why =>reason,what=>object/idea/action, which=>things] \n Ho=>[How=>manner,How many=>countable, \n How much=>non countable, How long=>time,How far=>distance]

*** Indefinite

**** Affirmative or Positive \n Rule: sub+[shall/will]+ verb-1st \n [ I / we => shall]\n [you/he/she/name/it/they => will]

**** Interrogative \n Rule: [shall/will]+sub+ verb-1st ? \n [ I / we => shall]\n [you/he/she/name/it/they => will]

**** Negative \n Rule: sub+ [shall/will]+not + verb-1st \n [ I / we => shall]\n [you/he/she/name/it/they => will]

*** Continuous

**** Affirmative or Positive \n Rule: sub+[shall/will]+ [be]+ verb-1st +[ing]\n [ I / we => shall]\n [you/he/she/name/it/they => will]

**** Interrogative \n Rule: [shall/will]+sub+ [be]+verb-1st +[ing] ? \n [ I / we => shall]\n [you/he/she/name/it/they => will]

**** Negative \n Rule: sub+ [shall/will]+[be]+[not] + verb-1st +[ing] \n [ I / we => shall]\n [you/he/she/name/it/they => will]

***[#blue] Perfect

**** Affirmative or Positive \n Rule: sub+ [shall/will]+[have]+verb-3rd \n [ I / we => shall]\n [you/he/she/name/it/they => will]

**** Interrogative \n Rule: [shall/will]+sub+[have]+verb-3rd ? \n [ I / we => shall]\n [you/he/she/name/it/they => will]

**** Negative \n Rule: sub+ [shall/will]+[not]+[have]+verb-3rd \n [ I / we => shall]\n [you/he/she/name/it/they => will]

*** Perfect Continuous

**** Affirmative or Positive \n Rule: sub+ [shall/will]+[have been]+verb-1st+[ing] +obj +[since/for]+ time \n[he/she/name/it =>has]\n[I/you/we/they => have]

**** Interrogative \n Rule: [shall/will]+sub+[have been]+verb-1st+[ing] +obj +[since/for]+ time ? \n[he/she/name/it =>has]\n[I/you/we/they => have]

**** Negative \n Rule: sub+ [shall/will]+[not]+[have been]+verb-1st+[ing] +obj +[since/for]+ time \n[he/she/name/it =>has]\n[I/you/we/they => have]

@endwbs

Conclusion

Sequence diagrams provide a detailed and structured way to visualize and document the flow of a system's interactions. They help in understanding the dynamic behavior of a system and are essential in the design and analysis phases of software development. By mastering sequence diagrams, you can better communicate and document how your system operates and interacts with various components and external entities.