+++ description = "Generate diagrams and flowcharts from text" title = "Mermaid" +++ With the [Mermaid](https://mermaidjs.github.io/) library and shortcode, you can generate diagrams and flowcharts from text, in a similar manner as Markdown. {{< mermaid >}} graph LR; If --> Then Then --> Else {{< /mermaid >}} {{% notice note %}} This only works in modern browsers. {{% /notice %}} {{% notice warning %}} Due to limitations with [Mermaid](https://github.com/mermaid-js/mermaid/issues/1846), it is currently not possible to use Mermaid code fences in an initially collapsed `expand` shortcode. This is a know issue and [can't be fixed by this theme](https://github.com/McShelby/hugo-theme-relearn/issues/187). {{% /notice %}} ## Usage The generated graphs can be be panned by dragging them and zoomed by using the mousewheel. On mobile devices you can use finger gestures. While the examples are using shortcode syntax it is recommended to use codefence syntax instead. This is because more and more other software supports Mermaid codefences (eg. GitHub) and so your markdown becomes more portable. {{% notice note %}} To use codefence syntax you have to turn off `guessSyntax` for the `markup.highlight` setting ([see the configuration section](#configuration)). {{% /notice %}} {{< tabs groupId="shortcode-codefence">}} {{% tab name="codefence" %}} ````plaintext ```mermaid graph LR; If --> Then Then --> Else ``` ```` {{% /tab %}} {{% tab name="shortcode" %}} ````go {{}} graph LR; If --> Then Then --> Else {{}} ```` {{% /tab %}} {{< /tabs >}} ### Parameter Parameter are only supported when using shortcode syntax. Defaults are used when using codefence syntax. | Name | Default | Notes | |:----------------------|:-----------------|:------------| | **align** | `center` | Allowed values are `left`, `center` or `right`. | | _**<content>**_ | _<empty>_ | Your mermaid graph. | ## Configuration Mermaid is configured with default settings. You can customize Mermaid's default settings for all of your files thru a JSON object in your `config.toml`, override these settings per page thru your pages frontmatter or override these setting per diagramm thru [diagram directives](https://mermaid-js.github.io/mermaid/#/directives?id=directives). The JSON object of your `config.toml` / frontmatter is forwarded into Mermaid's `mermaid.initialize()` function. See [Mermaid documentation](http://mermaid-js.github.io/mermaid/#/Setup?id=mermaidapi-configuration-defaults) for all allowed settings. The `theme` setting can also be set by your used color variant. This will be the sitewide default and can - again - be overridden by your settings in `config.toml`, frontmatter or diagram directives. {{% notice note %}} To use codefence syntax you have to turn off `guessSyntax` for the `markup.highlight` setting. {{% /notice %}} ### Global Configuration File ````toml [params] mermaidInitialize = "{ \"theme\": \"dark\" }" [markup] [markup.highlight] # if set to `guessSyntax = true`, there will be no unstyled code even if no language # was given BUT mermaid code fences will not work anymore! So this is a mandatory # setting for your site guessSyntax = false ```` ### Page's Frontmatter ````toml +++ mermaidInitialize = "{ \"theme\": \"dark\" }" +++ ```` ## Examples ### Flowchart with Non-Default Mermaid Theme ````go {{}} %%{init:{"theme":"forest"}}%% graph LR; A[Hard edge] -->|Link text| B(Round edge) B --> C{Decision} C -->|One| D[Result one] C -->|Two| E[Result two] {{}} ```` {{< mermaid align="left" >}} %%{init:{"theme":"forest"}}%% graph LR; A[Hard edge] -->|Link text| B(Round edge) B --> C{Decision} C -->|One| D[Result one] C -->|Two| E[Result two] {{< /mermaid >}} ### Sequence ````go {{}} 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! {{}} ```` {{< 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
prevail... John-->Alice: Great! John->Bob: How about you? Bob-->John: Jolly good! {{< /mermaid >}} ### GANTT ````go {{}} gantt dateFormat YYYY-MM-DD title Adding GANTT diagram functionality to Mermaid 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 {{}} ```` {{< mermaid >}} gantt dateFormat YYYY-MM-DD title Adding GANTT diagram functionality to Mermaid 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 {{< /mermaid >}} ### Class ````go {{}} classDiagram Class01 <|-- AveryLongClass : Cool Class03 *-- Class04 Class05 o-- Class06 Class07 .. Class08 Class09 --> C2 : Where am i? Class09 --* C3 Class09 --|> Class07 Class07 : equals() Class07 : Object[] elementData Class01 : size() Class01 : int chimp Class01 : int gorilla Class08 <--> C2: Cool label {{}} ```` {{< mermaid >}} classDiagram Class01 <|-- AveryLongClass : Cool Class03 *-- Class04 Class05 o-- Class06 Class07 .. Class08 Class09 --> C2 : Where am i? Class09 --* C3 Class09 --|> Class07 Class07 : equals() Class07 : Object[] elementData Class01 : size() Class01 : int chimp Class01 : int gorilla Class08 <--> C2: Cool label {{< /mermaid >}} ### State Diagram with Codefence Syntax ````go ```mermaid stateDiagram-v2 open: Open Door closed: Closed Door locked: Locked Door open --> closed: Close closed --> locked: Lock locked --> closed: Unlock closed --> open: Open ``` ```` ````mermaid stateDiagram-v2 open: Open Door closed: Closed Door locked: Locked Door open --> closed: Close closed --> locked: Lock locked --> closed: Unlock closed --> open: Open ````