Complete Guide to Markdown with Mermaid Diagrams#
This article demonstrates how to create various complex diagrams using Mermaid in Markdown documents, including flowcharts, sequence diagrams, Gantt charts, class diagrams, and state diagrams.
Flowchart Example#
Flowcharts are excellent for representing processes or algorithm steps.
graph TD
A[Start] --> B{Condition Check}
B -->|Yes| C[Process Step 1]
B -->|No| D[Process Step 2]
C --> E[Subprocess]
D --> E
subgraph E [Subprocess Details]
E1[Substep 1] --> E2[Substep 2]
E2 --> E3[Substep 3]
end
E --> F{Another Decision}
F -->|Option 1| G[Result 1]
F -->|Option 2| H[Result 2]
F -->|Option 3| I[Result 3]
G --> J[End]
H --> J
I --> J
Sequence Diagram Example#
Sequence diagrams show interactions between objects over time.
sequenceDiagram
participant User
participant WebApp
participant Server
participant Database
User->>WebApp: Submit Login Request
WebApp->>Server: Send Auth Request
Server->>Database: Query User Credentials
Database-->>Server: Return User Data
Server-->>WebApp: Return Auth Result
alt Auth Successful
WebApp->>User: Show Welcome Page
WebApp->>Server: Request User Data
Server->>Database: Get User Preferences
Database-->>Server: Return Preferences
Server-->>WebApp: Return User Data
WebApp->>User: Load Personalized Interface
else Auth Failed
WebApp->>User: Show Error Message
WebApp->>User: Prompt Re-entry
end
Gantt Chart Example#
Gantt charts are perfect for displaying project schedules and timelines.
gantt
title Website Development Project Timeline
dateFormat YYYY-MM-DD
axisFormat %m/%d
section Design Phase
Requirements Analysis :a1, 2023-10-01, 7d
UI Design :a2, after a1, 10d
Prototype Creation :a3, after a2, 5d
section Development Phase
Frontend Development :b1, 2023-10-20, 15d
Backend Development :b2, after a2, 18d
Database Design :b3, after a1, 12d
section Testing Phase
Unit Testing :c1, after b1, 8d
Integration Testing :c2, after b2, 10d
User Acceptance Testing :c3, after c2, 7d
section Deployment
Production Deployment :d1, after c3, 3d
Launch :milestone, after d1, 0d
Class Diagram Example#
Class diagrams show the static structure of a system, including classes, attributes, methods, and their relationships.
classDiagram
class User {
+String username
+String password
+String email
+Boolean active
+login()
+logout()
+updateProfile()
}
class Article {
+String title
+String content
+Date publishDate
+Boolean published
+publish()
+edit()
+delete()
}
class Comment {
+String content
+Date commentDate
+addComment()
+deleteComment()
}
class Category {
+String name
+String description
+addArticle()
+removeArticle()
}
User "1" -- "*" Article : writes
User "1" -- "*" Comment : posts
Article "1" -- "*" Comment : has
Article "1" -- "*" Category : belongs to
State Diagram Example#
State diagrams show the sequence of states an object goes through during its life cycle.
stateDiagram-v2
[*] --> Draft
Draft --> UnderReview : submit
UnderReview --> Draft : reject
UnderReview --> Approved : approve
Approved --> Published : publish
Published --> Archived : archive
Published --> Draft : retract
state Published {
[*] --> Active
Active --> Hidden : temporarily hide
Hidden --> Active : restore
Active --> [*]
Hidden --> [*]
}
Archived --> [*]
Pie Chart Example#
Pie charts are ideal for displaying proportions and percentage data.
pie title Website Traffic Sources Analysis
"Search Engines" : 45.6
"Direct Access" : 30.1
"Social Media" : 15.3
"Referral Links" : 6.4
"Other Sources" : 2.6
Conclusion#
Mermaid is a powerful tool for creating various types of diagrams in Markdown documents. This article demonstrated how to use flowcharts, sequence diagrams, Gantt charts, class diagrams, state diagrams, and pie charts. These diagrams can help you express complex concepts, processes, and data structures more clearly.
To use Mermaid, simply specify the mermaid language in a code block and describe the diagram using concise text syntax. Mermaid will automatically convert these descriptions into beautiful visual diagrams.
Try using Mermaid diagrams in your next technical blog post or project documentation - they will make your content more professional and easier to understand!
