PlantUML in Slidev
This skill covers using PlantUML for creating UML and technical diagrams in Slidev. PlantUML excels at creating standard UML diagrams with more detailed control than Mermaid.
When to Use This Skill
- Creating standard UML diagrams
- Complex sequence diagrams with detailed notation
- Component and deployment diagrams
- Use case diagrams
- Activity diagrams with swimlanes
- C4 architecture diagrams
Enabling PlantUML
PlantUML is supported via the plantuml code block:
@startuml Alice -> Bob: Hello Bob --> Alice: Hi! @enduml
Sequence Diagrams
Basic Sequence
@startuml participant User participant "Web Server" as WS participant Database as DB
User -> WS: HTTP Request activate WS WS -> DB: SQL Query activate DB DB --> WS: Result Set deactivate DB WS --> User: HTTP Response deactivate WS @enduml
Participant Types
@startuml actor User boundary "API Gateway" as API control "Auth Service" as Auth entity "User Entity" as UE database "PostgreSQL" as DB collections "Cache" as Cache queue "Message Queue" as MQ
User -> API: Request API -> Auth: Validate Auth -> DB: Query @enduml
Grouping and Alternatives
@startuml actor User participant Service
User -> Service: Login
alt Valid credentials Service --> User: Success else Invalid credentials Service --> User: Error 401 end
group Optional User -> Service: Refresh Token Service --> User: New Token end
loop Health Check Service -> Service: Ping end @enduml
Notes
@startuml participant Alice participant Bob
Alice -> Bob: Request note left: This is a note\non the left
Bob --> Alice: Response note right: This is a note\non the right
note over Alice, Bob: Note over both participants @enduml
Class Diagrams
Basic Class
@startuml class User { -id: Long -email: String -password: String +login(): Boolean +logout(): void }
class Order { -id: Long -total: BigDecimal +addItem(item: Item): void +removeItem(id: Long): void +checkout(): Boolean }
User "1" --> "*" Order: places @enduml
Interfaces and Abstract Classes
@startuml interface Serializable { +serialize(): String }
abstract class BaseEntity { #id: Long #createdAt: DateTime {abstract} +validate(): Boolean }
class User extends BaseEntity implements Serializable { -name: String +serialize(): String +validate(): Boolean } @enduml
Relationships
@startuml class A class B class C class D class E class F
A --|> B : extends C ..|> D : implements E --* F : composition G --o H : aggregation I --> J : association K ..> L : dependency @enduml
Packages
@startuml package "Domain Layer" { class User class Order }
package "Infrastructure Layer" { class UserRepository class OrderRepository }
package "Application Layer" { class UserService class OrderService }
UserService --> User UserService --> UserRepository @enduml
Use Case Diagrams
@startuml left to right direction
actor Customer actor Admin
rectangle "E-Commerce System" { usecase "Browse Products" as UC1 usecase "Add to Cart" as UC2 usecase "Checkout" as UC3 usecase "Manage Products" as UC4 usecase "Process Orders" as UC5 }
Customer --> UC1 Customer --> UC2 Customer --> UC3 Admin --> UC4 Admin --> UC5
UC3 ..> UC2 : <<include>> @enduml
Activity Diagrams
Basic Flow
@startuml start :Receive Order; if (Payment Valid?) then (yes) :Process Order; :Ship Items; else (no) :Notify Customer; :Cancel Order; endif stop @enduml
Swimlanes
@startuml |Customer| start :Submit Order; |Sales| :Review Order; if (Valid?) then (yes) |Warehouse| :Pick Items; :Pack Items; |Shipping| :Ship Package; |Customer| :Receive Package; else (no) |Sales| :Reject Order; |Customer| :Receive Notification; endif stop @enduml
Parallel Processing
@startuml start :Initialize; fork :Process A; fork again :Process B; fork again :Process C; end fork :Merge Results; stop @enduml
Component Diagrams
@startuml package "Frontend" { [React App] as Web [Mobile App] as Mobile }
package "Backend" { [API Gateway] [Auth Service] [User Service] [Order Service] }
package "Data Layer" { database "PostgreSQL" as DB database "Redis" as Cache queue "RabbitMQ" as MQ }
Web --> [API Gateway] Mobile --> [API Gateway] [API Gateway] --> [Auth Service] [API Gateway] --> [User Service] [API Gateway] --> [Order Service] [User Service] --> DB [Order Service] --> DB [Order Service] --> MQ [Auth Service] --> Cache @enduml
Deployment Diagrams
@startuml node "AWS Cloud" { node "VPC" { node "Public Subnet" { [Load Balancer] as LB }
node "Private Subnet" { node "ECS Cluster" { [API Container] as API [Worker Container] as Worker } }
node "Data Subnet" { database "RDS PostgreSQL" as DB database "ElastiCache Redis" as Cache } } }
actor User User --> LB LB --> API API --> DB API --> Cache Worker --> DB @enduml
State Diagrams
@startuml [*] --> Draft
Draft --> Submitted : submit() Submitted --> UnderReview : startReview() UnderReview --> Approved : approve() UnderReview --> Rejected : reject() Rejected --> Draft : revise() Approved --> Published : publish() Published --> [*]
Draft : entry / loadDraft() Draft : exit / saveDraft()
state UnderReview { [*] --> Reviewing Reviewing --> WaitingForInfo : requestInfo() WaitingForInfo --> Reviewing : infoProvided() } @enduml
Styling
Skinparams
@startuml skinparam backgroundColor #f8fafc skinparam roundCorner 10 skinparam shadowing false
skinparam class { BackgroundColor #e0f2fe BorderColor #0284c7 FontColor #0c4a6e }
skinparam sequence { ArrowColor #0284c7 LifeLineBorderColor #64748b ParticipantBackgroundColor #e0f2fe }
class User { +name: String } @enduml
Themes
@startuml !theme cerulean
class MyClass { +attribute: String } @enduml
Available themes: cerulean, materia, minty, sandstone, sketchy-outline, and more.
C4 Model Diagrams
Context Diagram
@startuml !include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Context.puml
Person(user, "Customer", "A user of our system") System(system, "E-Commerce", "Online shopping platform") System_Ext(payment, "Payment Gateway", "Handles payments") System_Ext(shipping, "Shipping Provider", "Delivers packages")
Rel(user, system, "Uses") Rel(system, payment, "Processes payments via") Rel(system, shipping, "Ships orders via") @enduml
Container Diagram
@startuml !include https://raw.githubusercontent.com/plantuml-stdlib/C4-PlantUML/master/C4_Container.puml
Person(user, "Customer")
System_Boundary(system, "E-Commerce Platform") { Container(web, "Web App", "React", "User interface") Container(api, "API", "Node.js", "Business logic") ContainerDb(db, "Database", "PostgreSQL", "Stores data") Container(queue, "Queue", "RabbitMQ", "Async processing") }
Rel(user, web, "Uses") Rel(web, api, "API calls") Rel(api, db, "Reads/Writes") Rel(api, queue, "Publishes") @enduml
Configuration
setup/plantuml.ts
import { definePlantUmlSetup } from '@slidev/types'
export default definePlantUmlSetup(() => {
return {
// Server URL (default uses public server)
server: 'https://www.plantuml.com/plantuml',
}
})Mermaid vs PlantUML
| Feature | Mermaid | PlantUML |
|---|---|---|
| Syntax | Simpler | More verbose |
| UML compliance | Partial | Full |
| Rendering | Client-side | Server-side |
| C4 diagrams | No | Yes |
| Swimlanes | No | Yes |
| Customization | Limited | Extensive |
Best Practices
- Use PlantUML for: Standard UML, C4, complex diagrams
- Use Mermaid for: Simple flowcharts, quick visualizations
- Add skinparams: Customize for your presentation theme
- Keep diagrams focused: One concept per diagram
- Use proper UML notation: Follow standards for clarity
Output Format
When creating PlantUML diagrams:
DIAGRAM TYPE: [sequence/class/component/etc.]
PURPOSE: [What it illustrates]
@startuml [skinparams if needed]
[diagram content]
@enduml
KEY ELEMENTS:
- [Element]: [What it represents]
NOTES:
- [Any additional context]