+++
title = "Mermaid"
weight = 8
description = "Generate diagrams, flowcharts, and piecharts  from text in a similar manner as markdown."
+++

[Mermaid](https://mermaidjs.github.io/) is library that helps you generate diagrams, flowcharts, and piecharts  from text in a similar manner as markdown.

With compose theme, you can use mermaid using a custom shortcode as follows:

### Sequence Diagrams

**Syntax**

```tpl
{{</* mermaid */>}}
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!
{{</* /mermaid */>}}
```

**Result**

{{< mermaid >}}
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!
{{< /mermaid >}}

### Flow Charts

**Syntax**

```tpl
{{</* mermaid */>}}
flowchart TB
  c1-->a2
  subgraph one
  a1-->a2
  end
  subgraph two
  b1-->b2
  end
  subgraph three
  c1-->c2
  end
  one --> two
  three --> two
  two --> c2
{{</* /mermaid */>}}
```
**Result**

{{< mermaid >}}
flowchart TB
  c1-->a2
  subgraph one
  a1-->a2
  end
  subgraph two
  b1-->b2
  end
  subgraph three
  c1-->c2
  end
  one --> two
  three --> two
  two --> c2
{{< /mermaid >}}

### Graphs

**Syntax**

```tpl
{{</* mermaid */>}}
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
{{</* /mermaid */>}}
```

**Result**

{{< mermaid >}}
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
{{< /mermaid >}}

**Syntax**

```tpl
{{</* mermaid */>}}
graph LR
  A[Hard edge] -->|Link text| B(Round edge)
  B --> C{Decision}
  C -->|One| D[Result one]
  C -->|Two| E[Result two]
{{</* /mermaid */>}}
```

**Result**

{{< mermaid >}}
graph LR
  A[Hard edge] -->|Link text| B(Round edge)
  B --> C{Decision}
  C -->|One| D[Result one]
  C -->|Two| E[Result two]
{{< /mermaid >}}

### Class Diagram

{{< mermaid >}}
classDiagram
  Animal <|-- Duck
  Animal <|-- Fish
  Animal <|-- Zebra
  Animal : +int age
  Animal : +String gender
  Animal: +isMammal()
  Animal: +mate()
  class Duck{
      +String beakColor
      +swim()
      +quack()
  }
  class Fish{
      -int sizeInFeet
      -canEat()
  }
  class Zebra{
      +bool is_wild
      +run()
  }
{{< /mermaid >}}


### State Diagram

{{< mermaid >}}
stateDiagram-v2
  [*] --> Active

  state Active {
    [*] --> NumLockOff
    NumLockOff --> NumLockOn : EvNumLockPressed
    NumLockOn --> NumLockOff : EvNumLockPressed
    --
    [*] --> CapsLockOff
    CapsLockOff --> CapsLockOn : EvCapsLockPressed
    CapsLockOn --> CapsLockOff : EvCapsLockPressed
    --
    [*] --> ScrollLockOff
    ScrollLockOff --> ScrollLockOn : EvScrollLockPressed
    ScrollLockOn --> ScrollLockOff : EvScrollLockPressed
  }
{{< /mermaid >}}

{{< mermaid >}}
stateDiagram-v2
  State1: The state with a note
  note right of State1
    Important information! You can write
    notes.
  end note
  State1 --> State2
  note left of State2 : This is the note to the left.
{{< /mermaid >}}

### Relationship Diagrams

**Syntax**

```tpl
{{</* mermaid */>}}
erDiagram
  CUSTOMER ||--o{ ORDER : places
  ORDER ||--|{ LINE-ITEM : contains
  CUSTOMER }|..|{ DELIVERY-ADDRESS : uses
{{</* /mermaid */>}}
```

**Result**

{{< mermaid >}}
erDiagram
  CUSTOMER ||--o{ ORDER : places
  ORDER ||--|{ LINE-ITEM : contains
  CUSTOMER }|..|{ DELIVERY-ADDRESS : uses
{{< /mermaid >}}

### User Journey

**Syntax**

```tpl
{{</* mermaid */>}}
journey
  title My working day
  section Go to work
    Make tea: 5: Me
    Go upstairs: 3: Me
    Do work: 1: Me, Cat
  section Go home
    Go downstairs: 5: Me
    Sit down: 5: Me
{{</* /mermaid */>}}

```

**Result**

{{< mermaid >}}
journey
  title My working day
  section Go to work
    Make tea: 5: Me
    Go upstairs: 3: Me
    Do work: 1: Me, Cat
  section Go home
    Go downstairs: 5: Me
    Sit down: 5: Me
{{< /mermaid >}}

### Gantt

**Syntax**

```tpl
{{</* mermaid */>}}
gantt
  dateFormat  YYYY-MM-DD
  title       Adding GANTT diagram functionality to mermaid
  excludes    weekends
  %% (`excludes` accepts specific dates in YYYY-MM-DD format, days of the week ("sunday") or "weekends", but not the word "weekdays".)

  section A section
  Completed task            :done,    des1, 2014-01-06,2014-01-08
  Active task               :active,  des2, 2014-01-09, 3d
  Future task               :         des3, after des2, 5d
  Future task2              :         des4, after des3, 5d

  section Critical tasks
  Completed task in the critical line :crit, done, 2014-01-06,24h
  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
{{</* /mermaid */>}}
```

**Result**

{{< mermaid >}}
gantt
  dateFormat  YYYY-MM-DD
  title       Adding GANTT diagram functionality to mermaid
  excludes    weekends
  %% (`excludes` accepts specific dates in YYYY-MM-DD format, days of the week ("sunday") or "weekends", but not the word "weekdays".)

  section A section
  Completed task            :done,    des1, 2014-01-06,2014-01-08
  Active task               :active,  des2, 2014-01-09, 3d
  Future task               :         des3, after des2, 5d
  Future task2              :         des4, after des3, 5d

  section Critical tasks
  Completed task in the critical line :crit, done, 2014-01-06,24h
  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
{{< /mermaid >}}

### Pie Chart

```tpl
{{</* mermaid */>}}
pie
  title Key elements in Product X
  "Calcium" : 42.96
  "Potassium" : 50.05
  "Magnesium" : 10.01
  "Iron" :  5
{{</* /mermaid */>}}

```

**Result**

{{< mermaid >}}
pie
  title Key elements in Product X
  "Calcium" : 42.96
  "Potassium" : 50.05
  "Magnesium" : 10.01
  "Iron" :  5
{{< /mermaid >}}