Mermaid Cheat Sheet

Taken from: Tutorial

Cheat Sheet for Mermaid.

1. Flowcharts

A flowchart is a type of diagram that represents an algorithm, workflow or process. The flowchart shows the steps as boxes of various kinds, and their order by connecting the boxes with arrows. This diagrammatic representation illustrates a solution model to a given problem.

1.1 Graph

Possible directions are:

TB - top bottom
BT - bottom top
RL - right left
LR - left right
TD - same as TB

Direction	Diagram	Definition
TB	graph TB;A-->B;	graph TB; A-->B;
BT	graph BT;A-->B;	graph BT; A-->B;
RL	graph RL;A-->B;	graph RL; A-->B;
LR	graph LR;A-->B;	graph LR; A-->B;
TD	graph TD;A-->B;	graph TD; A-->B;

1.2 Nodes & shapes

Feature	Diagram	Definition
Node(Default)	graph LR;id;	graph LR; id;
Node with Text	graph LR;id1[This is the text in the box]	graph LR; id1[This is the text in the box]
Node with Round Edges	graph LR;id1(This is the text in the box)	graph LR; id1(This is the text in the box)
Node in Circle Form	graph LR;id1((This is the text in the circle))	graph LR; id1((This is the text in the circle))
Node in Asymmetric Shape	graph LR;id1>This is the text in the box]	graph LR; id1>This is the text in the box]
Node in Rhombus Form	graph LR;id1{This is the text in the box}	graph LR; id1{This is the text in the box}

1.3 Links Between Nodes

Feature	Diagram	Definition
Link with Arrow Head	graph LR;A-->B	graph LR; A-->B
Open Link	graph LR;A---B	graph LR; A---B
Text on Links(1)	graph LR;A-- This is the text ---B	graph LR; A-- This is the text ---B
Text on Links(2)	graph LR;A---\|This is the text\|B	graph LR; A---\|This is the text\|B
Link with Arrow Head and Text(1)	graph LR;A-->\|text\|B	graph LR; A-->\|text\|B
Link with Arrow Head and Text(2)	graph LR;A-- text -->B	graph LR; A-- text -->B
Dotted Link	graph LR;A-.->B;	graph LR; A-.->B;
Dotted Link with Text	graph LR;A-. text .-> B	graph LR; A-. text .-> B
Thick Link	graph LR;A ==> B	graph LR; A ==> B
Thick link with text	graph LR;A == text ==> B	graph LR; A == text ==> B

1.4 Subgraphs

Syntax:

subgraph title
    graph definition
end

Example:

graph TB
    c1 --> a2
    subgraph one
    a1 --> a2
    end
    subgraph two
    b1 --> b2
    end
    subgraph three
    c1 --> c2
    end

graph TB; subgraph one; a1 --> a2; end; subgraph two; b1 --> b2; end; subgraph three; c1 --> c2; end; c1 --> a2;

2. Sequence Diagrams

A Sequence diagram is an interaction diagram that shows how processes operate with one another and in what order.

2.1 Participants

The participants or actors are rendered in order of appearance in the diagram source text.

sequenceDiagram
    participant Alice
    participant John
    Alice ->> John: Hello John, how are you?
    John -->> Alice: Great!

sequenceDiagram; participant Alice; participant John; Alice ->> John: Hello John, how are you?; John -->> Alice: Great!

You can specify the actor’s order of appearance to show the participants in a different order.

sequenceDiagram
    participant John
    participant Alice
    Alice ->> John: Hello John, how are you?
    John -->> Alice: Great!

sequenceDiagram; participant John; participant Alice; Alice ->> John: Hello John, how are you?; John -->> Alice: Great!;

The participants can be defined implicitly without specifying them with the participant keyword.

sequenceDiagram
    Alice ->> John: Hello John, how are you?
    John -->> Alice: Great!

sequenceDiagram; Alice ->> John: Hello John, how are you? John -->> Alice: Great!

2.2 Aliases

The participant can have a convenient identifier and a descriptive label.

sequenceDiagram
    participant A as Alice
    participant J as John
    A ->> J: Hello John, how are you?
    J -->> A: Great!

sequenceDiagram; participant A as Alice participant J as John A ->> J: Hello John, how are you? J -->> A: Great!

2.3 Messages

Messages can be of two displayed either solid or with a dotted line.

[Actor][Arrow][Actor]:Message text

There are six types of arrows currently supported:

Arrow Type	Description
->	Solid line without arrow
–>	Dotted line without arrow
-»	Solid line with arrowhead
–»	Dotted line with arrowhead
-x	Solid line with a cross at the end (async)
–x	Dotted line with a cross at the end (async)

2.4 Activations

Activate and deactivate an actor.

sequenceDiagram
    Alice ->> John: Hello John, how are you?
    activate John
    John -->> Alice: Great!
    deactivate John

sequenceDiagram; Alice ->> John: Hello John, how are you? activate John John -->> Alice: Great! deactivate John

Shortcut notation by appending +/- suffix to the message arrow.

sequenceDiagram
    Alice ->>+ John: Hello John, how are you?
    John -->>- Alice: Great!

sequenceDiagram; Alice ->>+ John: Hello John, how are you? John -->>- Alice: Great!

Activations can be stacked for same actor:

sequenceDiagram
    Alice ->>+ John: Hello John, how are you?
    Alice ->>+ John: John, can you hear me?
    John -->>- Alice: Hi Alice, I can hear you!
    John -->>- Alice: I feel great!

sequenceDiagram; Alice ->>+ John: Hello John, how are you? Alice ->>+ John: John, can you hear me? John -->>- Alice: Hi Alice, I can hear you! John -->>- Alice: I feel great!

2.5 Notes

Add notes to a sequence diagram by the notation Note.

Note [ right of | left of | over ] [Actor]: Text in note content

1) Right Side

sequenceDiagram
    participant John
    Note right of John: Text in note

sequenceDiagram; participant John; Note right of John: Text in note;

2) Left Side

sequenceDiagram
    participant John
    Note left of John: Text in note

sequenceDiagram; participant John; Note left of John: Text in note;

3) Over

sequenceDiagram
    participant John
    Note over John: Text in note

sequenceDiagram; participant John; Note over John: Text in note;

4) Create notes spanning two participants

sequenceDiagram
    Alice ->> John: Hello John, how are you?
    Note over Alice,John: A typical interaction

sequenceDiagram; Alice ->> John: Hello John, how are you? Note over Alice,John: A typical interaction

2.6 Loops

Express loops in a sequence diagram by the notation loop.

loop Loop text
... statements ...
end

sequenceDiagram
    Alice -> John: Hello John, how are you?
    loop Every minute
        John --> Alice: Great!
    end

sequenceDiagram Alice -> John: Hello John, how are you? loop Every minute John --> Alice: Great! end

2.7 Alt

Express alternative paths in a sequence diagram by the notation alt.

alt Describing text
... statements ...
else
... statements ...
end

Or, if there is sequence that is optional (if without else).

opt Describing text
... statements ...
end

Example:

sequenceDiagram
    Alice ->> John: Hello John, how are you?
    alt is sick
        John ->> Alice: Not so good :(
    else is well
        John ->> Alice: Feeling fresh like a daisy
    end
    opt Extra response
        John ->> Alice: Thanks for asking
    end

sequenceDiagram; Alice ->> John: Hello John, how are you? alt is sick John ->> Alice: Not so good :( else is well John ->> Alice: Feeling fresh like a daisy end opt Extra response John ->> Alice: Thanks for asking end

3. Gantt Diagrams

A Gantt chart is a type of bar chart, first developed by Karol Adamiecki in 1896, and independently by Henry Gantt in the 1910s, that illustrates a project schedule. Gantt charts illustrate the start and finish dates of the terminal elements and summary elements of a project.

gantt
  title A Gantt Diagram
    dateFormat  YYYY-MM-DD
  section Section
    First Task       :a1, 2018-07-01, 30d
    Another Task     :after a1, 20d

gantt title A Gantt Diagram dateFormat YYYY-MM-DD section Section First Task :a1, 2018-07-01, 30d Another Task :after a1, 20d section Another Second Task :2018-07-12, 12d Third Task : 24d

gantt
       dateFormat  YYYY-MM-DD
       title Adding GANTT diagram functionality to mermaid

       section A section
       Completed task            :done,    des1, 2018-01-06,2018-01-08
       Active task               :active,  des2, 2018-01-09, 3d
       Future task               :         des3, after des2, 5d
       Future task2              :         des4, after des3, 5d

       section Critical tasks
       Completed task in the critical line :crit, done, 2018-01-06,24h
       Implement parser and jison          :crit, done, after des1, 2d
       Create tests for parser             :crit, active, 3d
       Future task in critical line        :crit, 5d
       Create tests for renderer           :2d
       Add to mermaid                      :1d

       section Documentation
       Describe gantt syntax               :active, a1, after des1, 3d
       Add gantt diagram to demo page      :after a1  , 20h
       Add another diagram to demo page    :doc1, after a1  , 48h

       section Last section
       Describe gantt syntax               :after doc1, 3d
       Add gantt diagram to demo page      :20h
       Add another diagram to demo page    :48h

gantt; dateFormat YYYY-MM-DD title Adding GANTT diagram functionality to mermaid section A section Completed task :done, des1, 2018-01-06,2018-01-08 Active task :active, des2, 2018-01-09, 3d Future task : des3, after des2, 5d Future task2 : des4, after des3, 5d section Critical tasks Completed task in the critical line :crit, done, 2018-01-06,24h Implement parser and jison :crit, done, after des1, 2d Create tests for parser :crit, active, 3d Future task in critical line :crit, 5d Create tests for renderer :2d Add to mermaid :1d section Documentation Describe gantt syntax :active, a1, after des1, 3d Add gantt diagram to demo page :after a1 , 20h Add another diagram to demo page :doc1, after a1 , 48h section Last section Describe gantt syntax :after doc1, 3d Add gantt diagram to demo page :20h Add another diagram to demo page :48h

4. Demos

4.1 Basic Flowchart

graph LR
    A[Square Rect] -- Link text --> B((Circle))
    A --> C(Round Rect)
    B --> D{Rhombus}
    C --> D

graph LR; A[Square Rect] -- Link text --> B((Circle)); A --> C(Round Rect); B --> D{Rhombus}; C --> D;

4.2 Flowchart with Decision

graph TD
    A[Christmas] -->|Get money| B(Go shopping)
    B --> C{Let me think}
    C -->|One| D[Laptop]
    C -->|Two| E[iPhone]
    C -->|Three| F[fa:fa-car Car]

graph TD; A[Christmas] -->|Get money| B(Go shopping); B --> C{Let me think}; C -->|One| D[Laptop]; C -->|Two| E[iPhone]; C -->|Three| F[fa:fa-car Car];

4.3 Larger Flowchart with Some Styling

graph TB
    sq[Square shape] --> ci((Circle shape))

    subgraph A
        od>Odd shape]-- Two line<br/>edge comment --> ro
        di{Diamond with <br/> line break} -.-> ro(Rounded<br>square<br>shape)
        di==>ro2(Rounded square shape)
    end

    %% Notice that no text in shape are added here instead that is appended further down
    e --> od3>Really long text with linebreak<br>in an Odd shape]

    %% Comments after double percent signs
    e((Inner / circle<br>and some odd <br>special characters)) --> f(,.?!+-*ز)

    cyr[Cyrillic]-->cyr2((Circle shape Начало));

     classDef green fill:#9f6,stroke:#333,stroke-width:2px
     classDef orange fill:#f96,stroke:#333,stroke-width:4px
     class sq,e green
     class di orange

4.4 Basic Sequence Diagram

sequenceDiagram
    Alice ->> Bob: Hello Bob, how are you?
    Bob-->>John: How about you John?
    Bob--x Alice: I am good thanks!
    Bob-x John: I am good thanks!
    Note right of John: Bob thinks a long<br/>long time, so long<br/>that the text does<br/>not fit on a row.

    Bob-->Alice: Checking with John...
    Alice->John: Yes... John, how are you?

sequenceDiagram; Alice ->> Bob: Hello Bob, how are you?; Bob-->>John: How about you John?; Bob--x Alice: I am good thanks!; Bob-x John: I am good thanks!; Note right of John: Bob thinks a long
long time, so long
that the text does
not fit on a row.; Bob-->Alice: Checking with John... Alice->John: Yes... John, how are you?

4.5 Message to Self in Loop

sequenceDiagram
    participant Alice
    participant Bob
    Alice->>John: Hello John, how are you?
    loop Healthcheck
        John->>John: Fight against hypochondria
    end
    Note right of John: Rational thoughts<br/>prevail...
    John-->>Alice: Great!
    John->>Bob: How about you?
    Bob-->>John: Jolly good!

sequenceDiagram; participant Alice; participant Bob; Alice->>John: Hello John, how are you?; loop Healthcheck; John->>John: Fight against hypochondria; end; Note right of John: Rational thoughts
prevail...; John-->>Alice: Great!; John->>Bob: How about you?; Bob-->>John: Jolly good!;