Generation of diagrams and flowcharts from text in a similar manner as markdown. (2024)

Generation of diagrams and flowcharts from text in a similar manner as markdown.

Ever wanted to simplify documentation and avoid heavy tools like Visio when explaining your code?

This is why mermaid was born, a simple markdown-like script language for generating charts from text via javascript. Try it using our editor.

Code examples below:

An example of a flowchart

graph TD; A-->B; A-->C; B-->D; C-->D;

An example of a sequence diagram

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!

Example code for a gantt diagram

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

Play with mermaid using this editor or this live editor.

Credits

Many thanks to the d3 and dagre-d3 projects for providing
the graphical layout and drawing libraries! Thanks also to the
js-sequence-diagram project for usage of the grammar for the
sequence diagrams.

Mermaid was created by Knut Sveidqvist for easier documentation.

Knut has not done all work by himself, here is the full list of the projects contributors.

Mermaid is supported in a number of publishing systems and editors. Please report if a plugin/editor is missing from the list below:

• Support in LightPaper 1.2+. Howto. Discout with code MERMAID_25
• gitbook-plugin
• light table
• Confluence plugin
• Using mermaid via docpad
• Using mermaid in Jekyll
• Using mermaid via Octopress
• Mardown editor Haroopad
• Plugin for atom
• Markdown Plus
• Vim Plugin
• Sphinx extension
• Pandoc filter
• hads

An editor is available for creating diagrams. With it you can quickly start writing mermaid diagrams. It is possible to:

• save the result as a svg
• get a link to a viewer of the diagram

• get a link to edit of the diagram to share a diagram so that someone else can tweak it and send a new link back

• Editor

Installation

Either use the npm or bower package managers as per below:

bower install mermaid --save-dev

npm install mermaid --save-dev

Or download a javascript bundle and a stylesheet, e.g. the urls below are for the default style and the all-in-one javascript - note that #version# should be replaced with version of choice:

https://cdn.rawgit.com/knsv/mermaid/#version#/dist/mermaid.csshttps://cdn.rawgit.com/knsv/mermaid/#version#/dist/mermaid.min.js

Ex:

• js version 6.0.0

Checkout the latest version and other styles such as forest and dark.

There are some bundles to choose from:

• mermaid.js, mermaid.min.js This bundle contains all the javascript libraries you need to run mermaid
• mermaid.slim.js, mermaid.slim.min.js This bundle does not contain d3 which is useful for sites that already have d3 in place
• mermaidAPI.js, mermaidAPI.min.js, This bundle does not contain the web integration provided in the other packages but has a render function instead returns svg code.

Important:

It's best to use a specific tag or commit hash in the URL (not a branch). Files are cached permanently after the first request.

Read more about that at https://rawgit.com/

Simple usage on a web page

The easiest way to integrate mermaid on a web page requires two elements:

1. Inclusion of the mermaid framework in the html page using a script tag
2. A graph definition on the web page

If these things are in place mermaid listens to the page load event and when fires, when the page has loaded, it will
locate the graphs n the page and transform them to svg files.

Include mermaid on your web page:

<script src="mermaid.min.js"></script><script>mermaid.initialize({startOnLoad:true});</script>

Further down on your page mermaid will look for tags with class="mermaid". From these tags mermaid will try to
read the chart definiton which will be replaced with the svg chart.

Define a chart like this:

<div class="mermaid"> CHART DEFINITION GOES HERE</div>

Would end up like this:

<div class="mermaid" id="mermaidChart0"> <svg> Chart ends up here </svg></div>

An id is also added to mermaid tags without id.

Labels out of bounds

If you use dynamically loaded fonts that are loaded through CSS, such as Google fonts, mermaid should wait for the
whole page to have been loaded (dom + assets, particularly the fonts file).

$(document).load(function() {
mermaid.initialize();
});
over

$(document).ready(function() {
mermaid.initialize();
});

Not doing so will most likely result in mermaid rendering graphs that have labels out of bounds. The default integration
in mermaid uses the window.load event to start rendering.

Calling mermaid.init

By default, mermaid.init will be called when the document is ready, finding all elements with
class="mermaid". If you are adding content after mermaid is loaded, or otherwise need
finer-grained control of this behavior, you can call init yourself with:

• a configuration object
• some nodes, as
  • a node
  • an a array-like of nodes
  • or W3C selector that will find your nodes

Example:

mermaid.init({noteMargin: 10}, ".someOtherClass");

Or with no config object, and a jQuery selection:

mermaid.init(undefined, $("#someId .yetAnotherClass"));

Usage with browserify

The reader is assumed to know about CommonJS style of module handling and how to use browserify. If not a good place
to start would be http://browserify.org/ website.

Minimalistic javascript:

mermaid = require('mermaid');console.log('Test page! mermaid version'+mermaid.version());

Bundle the javascript with browserify.

Us the created bundle on a web page as per example below:

<!DOCTYPE html><html><head> <meta charset="UTF-8"> <link rel="stylesheet" href="mermaid.css" /> <script src="bundle.js"></script></head><body> <div class="mermaid"> graph LR A-->B B-->C C-->A D-->C </div></body></html>

API usage

The main idea with the API is to be able to call a render function with graph defintion as a string. The render function
will render the graph and call a callback with the resulting svg code. With this approach it is up to the site creator to
fetch the graph definition from the site, perhaps from a textarea, render it and place the graph somewhere in the site.

To do this, include mermaidAPI on your web website instead of mermaid.js. The example below show an outline of how this
could be used. The example just logs the resulting svg to the javascript console.

<script src="mermaidAPI.js"></script><script> mermaidAPI.initialize({ startOnLoad:false }); $(function(){ // Example of using the API var element = document.querySelector("#graphDiv"); var insertSvg = function(svgCode, bindFunctions){ element.innerHTML = svgCode; }; var graphDefinition = 'graph TB\na-->b'; var graph = mermaidAPI.render('graphDiv', graphDefinition, insertSvg); });</script>

Sample of API usage together with browserify

$ = require('jquery');mermaidAPI = require('mermaid').mermaidAPI;mermaidAPI.initialize({ startOnLoad:false });$(function(){ var graphDefinition = 'graph TB\na-->b'; var cb = function(html){ console.log(html); } mermaidAPI.render('id1',graphDefinition,cb);});

Binding events

Sometimes the generated graph also has defined interactions like tooltip and click events. When using the API one must
add those events after the graph has been inserted into the DOM.

The example code below is an extract of wheat mermaid does when using the API. The example show how it is possible to
bind events to a svg when using the API for rendering.

 var insertSvg = function(svgCode, bindFunctions){ element.innerHTML = svgCode; if(typeof callback !== 'undefined'){ callback(id); } bindFunctions(element); }; var id = 'theGraph'; mermaidAPI.render(id,txt,insertSvg, element);

1. The graph is generated using the render call.
2. After generation the render function calls the provided callback function, in this case its called insertSvg.
3. The callback function is called with two parameters, the svg code of the generated graph and a function. This
   function binds events to the svg after it is inserted into the DOM.
4. Insert the svg code into the DOM for presentation
5. Call the binding function that bainds the events

Example of a marked renderer

This is the renderer used for transforming the documentation from markdown to html with mermaid diagrams in the html.

 var renderer = new marked.Renderer(); renderer.code = function (code, language) { if(code.match(/^sequenceDiagram/)||code.match(/^graph/)){ return '<div class="mermaid">'+code+'</div>'; } else{ return '<pre><code>'+code+'</code></pre>'; } };

Another example in coffeescript that also includes the mermaid script tag into the generated markup.

marked = require 'marked'module.exports = (options) -> hasMermaid = false renderer = new marked.Renderer() renderer.defaultCode = renderer.code renderer.code = (code, language) -> if language is 'mermaid' html = '' if not hasMermaid hasMermaid = true html += '&ltscript src="'+options.mermaidPath+'"></script>' html + '&ltdiv class="mermaid">'+code+'</div>' else @defaultCode(code, language) renderer

Advanced usage

Error handling

When the parser encounters invalid syntax the mermaid.parseError function is called. It is possible to override this
function in order to handle the error in an application specific way.

Parsing text without rendering

It is also possible to validate the syntax before rendering in order to streamline the user experience. The function
mermaid.parse(txt) takes a text string as an argument and returns true if the text is syntactically correct and
false if it is not. The parseError function will be called when the parse function returns false.

The code-example below in meta code illustrates how this could work:

mermaid.parseError = function(err,hash){ displayErrorInGui(err);};var textFieldUpdated = function(){ var textStr = getTextFromFormField('code'); if(mermaid.parse(textStr)){ reRender(textStr) }};bindEventHandler('change', 'code', textFieldUpdated);

Mermaid takes a number of options which lets you tweak the rendering of the diagrams. Currently there are three ways of
setting the options in mermaid.

1. Instantiation of the configuration using the initialize call
2. Using the global mermaid object - deprecated
3. using the global mermaid_config object - deprecated
4. Instantiation of the configuration using the mermaid.init call

The list above has two ways to many of doing this. Three are deprecated and will eventually be removed. The list of
configuration objects are described in the mermaidAPI documentation.

Using the mermaidAPI.initialize/mermaid.initialize call

The future proof way of setting the configuration is by using the initialization call to mermaid or mermaidAPi depending
on what kind of integration you use.

 <script src="../dist/mermaid.js"></script> <script> var config = { startOnLoad:true, flowchart:{ useMaxWidth:false, htmlLabels:true } }; mermaid.initialize(config); </script>

Using the mermaid object

Is it possible to set some configuration via the mermaid object. The two parameters that are supported using this
approach are:

• mermaid.startOnLoad
• mermaid.htmlLabels

mermaid.startOnLoad = true;

Using the mermaid_config

Is it possible to set some configuration via the mermaid object. The two parameters that are supported using this
approach are:

• mermaid_config.startOnLoad
• mermaid_config.htmlLabels

mermaid_config.startOnLoad = true;

Using the mermaid.init call

Is it possible to set some configuration via the mermaid object. The two parameters that are supported using this
approach are:

• mermaid_config.startOnLoad
• mermaid_config.htmlLabels

mermaid_config.startOnLoad = true;

Graph

This statement declares a new graph and the direction of the graph layout.

%% Example codegraph TD

This declares a graph oriented from top to bottom.

graph TD Start --> Stop

%% Example codegraph LR

This declares a graph oriented from left to right.

Possible directions are:

• TB - top bottom
• BT - bottom top
• RL - right left

• LR - left right

• TD - same as TB

graph LR Start --> Stop

Nodes & shapes

A node (default)

graph LR id1

graph LR id

Note that the id is what is displayed in the box.

A node with text

It is also possible to set text in the box that differs from the id. If this is done several times, it is the last text
found for the node that will be used. Also if you define edges for the node later on, you can omit text definitions. The
one previously defined will be used when rendering the box.

graph LR id1[This is the text in the box]

graph LR id1[This is the text in the box]

A node with round edges

graph LR id1(This is the text in the box);

graph LR id1(This is the text in the box)

A node in the form of a circle

graph LR id1((This is the text in the circle));

graph LR id1((This is the text in the circle))

A node in an asymetric shape

graph LR id1>This is the text in the box]

graph LR id1>This is the text in the box]

Currently only the shape above is possible and not its mirror. This might change with future releases.

A node (rhombus)

graph LR id1{This is the text in the box}

graph LR id1{This is the text in the box}

Links between nodes

Nodes can be connected with links/edges. It is possible to have different types of links or attach a text string to a link.

A link with arrow head

graph LR A-->B

graph LR; A-->B

An open link

graph LR A --- B

graph LR; A --- B

Text on links

A-- This is the text --- B

or

A---|This is the text|B;

graph LR; A-- This is the text ---B

A link with arrow head and text

A-->|text|B

graph LR; A-->|text|B

or

A-- text -->B

graph LR; A-- text -->B

Dotted link

-.->

graph LR; A-.->B;

Dotted link with text

-. text .->

graph LR; A-. text .-> B

Thick link

==>

graph LR; A ==> B

Thick link with text

== text ==>

graph LR; A == text ==> B

Special characters that break syntax

It is possible to put text within quotes in order to render more troublesome characters. As in the example below:

graph LR d1["This is the (text) in the box"]

graph LR id1["This is the (text) in the box"]

Entity codes to escape characters

It is possible to escape characters using the syntax examplified here.

The flowchart defined by the following code:

 graph LR A["A double quote:#quot;"] -->B["A dec char:#9829;"]

This would render to the diagram below:

graph LR A["A double quote:#quot;"] -->B["A dec char:#9829;"]

Subgraphs

subgraph title graph definitionend

An example below:

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

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

Interaction

It is possible to bind a click event to a node, the click can lead to either a javascript callback or to a link which will be opened in a new browser tab.

click nodeId callback

• nodeId is the id of the node
• callback is the name of a javascript function defined on the page displaying the graph, the function will be called with the nodeId as parameter.

Examples of tooltip usage below:

<script> var callback = function(){ alert('A callback was triggered'); }<script>

graph LR; A-->B; click A callback "Tooltip for a callback" click B "http://www.github.com" "This is a tooltip for a link"

The tooltip text is surrounded in double quotes. The styles of the tooltip are set by the class .mermaidTooltip.

graph LR; A-->B; click A callback "Tooltip" click B "http://www.github.com" "This is a link"

When integration mermaid using the mermaidAPI #mermaidapi the function that binds the events need to be run when the finished graph has been added to the page. This is described in the API usage section.

Styling and classes

Styling links

It is possible to style links. For instance you might want to style a link that is going backwards in the flow. As links
have no ids in the same way as nodes, some other way of deciding what style the links should be attached to is required.
Instead of ids, the order number of when the link was defined in the graph is used. In the example below the style
defined in the linkStyle statement will belong to the fourth link in the graph:

linkStyle 3 stroke:#ff3,stroke-width:4px;

Styling a node

It is possible to apply specific styles such as a thicker border or a different background color to a node.

%% Example codegraph LR id1(Start)-->id2(Stop) style id1 fill:#f9f,stroke:#333,stroke-width:4px; style id2 fill:#ccf,stroke:#f66,stroke-width:2px,stroke-dasharray: 5, 5;

graph LR id1(Start)-->id2(Stop) style id1 fill:#f9f,stroke:#333,stroke-width:4px style id2 fill:#ccf,stroke:#f66,stroke-width:2px,stroke-dasharray: 5, 5

Classes

More convenient then defining the style every time is to define a class of styles and attach this class to the nodes that
should have a different look.

a class definition looks like the example below:

 classDef className fill:#f9f,stroke:#333,stroke-width:4px;

Attachment of a class to a node is done as per below:

 class nodeId1 className;

It is also possible to attach a class to a list of nodes in one statement:

 class nodeId1,nodeId2 className;

Css classes

It is also possible to pre dine classes in css styles that can be applied from the graph definition as in the example
below:
Example style

Example definition

graph LR; A-->B[AAABBB]; B-->D; class A cssClass;

Default class

If a class is named default it will be assigned to all classes without specific class definitions.

 classDef default fill:#f9f,stroke:#333,stroke-width:4px;

Basic support for fontawesome

It is possible to add icons from fontawesome. In order to do so, you need to add the fontwesome as described in the instructions at
the fontawesome web site.

The icons are acessed via the syntax fa:#icon class name#.

The example code below

graph TD B["fa:fa-twitter for peace"] B-->C[fa:fa-ban forbidden] B-->D(fa:fa-spinner); B-->E(A fa:fa-camera-retro perhaps?);

Would render the graph below:

graph TD B["fa:fa-twitter for peace"] B-->C[fa:fa-ban forbidden] B-->D(fa:fa-spinner); B-->E(A fa:fa-camera-retro perhaps?);

Graph declarations with spaces between vertices and link and without semicolon

• In graph declarations, the statements also can now end without a semicolon. After release 0.2.16, ending a graph statement with semicolon is just optional. So the below graph declaration is also valid along with the old declarations of the graph.

• A single space is allowed between vertices and the link. However there should not be any space between a vertex and its text and a link and its text. The old syntax of graph declaration will also work and hence this new feature is optional and is introduce to improve readability.

Below is the new declaration of the graph edges which is also valid along with the old declaration of the graph edges.

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

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

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

Mermaid can render sequence diagrams. The code snippet below:

%% Example of sequence diagramsequenceDiagram Alice->>John: Hello John, how are you? John-->>Alice: Great!

Renders the following diagram:

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

Syntax

Participants

The participants can be defined implicitly as in the first example on this page. The participants or actors are
rendered in order of appearance in the diagram source text. Sometimes you might want to show the participants in a
different order than how they appear in the first message. It is possible to specify the actor's order of
appearance by doing the following:

%% Example of sequence diagramsequenceDiagram participant John participant Alice Alice->>John: Hello John, how are you? John-->>Alice: Great!

Renders to the diagram below:

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

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:

-> which will render a solid line without arrow

--> which will render a dotted line without arrow

->> which will render a solid line with arrowhead

-->> which will render a dotted line with arrowhead

-x which will render a solid line with a cross at the end (async)

--x which will render a dotted line with a cross at the end (async)

Activations

It is possible to activate and deactivate an actor. (de)activation can be dedicated declarations:

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

Renders to the diagram below:

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

There is also a shortcut notation by appending +/- suffix to the message arrow:

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 yoy hear me? John-->>-Alice: Hi Alice, I can hear you! John-->>-Alice: I feel great!

Stacked activations look like this:

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

Notes

It is possible to add notes to a sequence diagram. This is done by the notation
Note [ right of | left of | over ] [Actor]: Text in note content

See the example below:

%% Example of sequence diagramsequenceDiagram participant John Note right of John: Text in note

Renders to the diagram below:

sequenceDiagram participant John Note right of John: Text in note

It is also possible to 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

Loops

It is possible to express loops in a sequence diagram. This is done by the notation

loop Loop text... statements ...end

See the example below

%% Example of sequence diagramsequenceDiagram Alice->John: Hello John, how are you? loop Reply every minute John-->Alice: Great! end

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

Alt

It is possible to express alternative paths in a sequence diagram. This is done by the notation

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

or if there is sequence that is optional (if without else).

opt Describing text... statements ...end

See the example below

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

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

Styling

Styling of the a sequence diagram is done by defining a number of css classes. During rendering these classes are extracted from the

Classes used

Sample stylesheet

body { background: white;}.actor { stroke: #CCCCFF; fill: #ECECFF;}text.actor { fill:black; stroke:none; font-family: Helvetica;}.actor-line { stroke:grey;}.messageLine0 { stroke-width:1.5; stroke-dasharray: "2 2"; marker-end:"url(#arrowhead)"; stroke:black;}.messageLine1 { stroke-width:1.5; stroke-dasharray: "2 2"; stroke:black;}#arrowhead { fill:black;}.messageText { fill:black; stroke:none; font-family: 'trebuchet ms', verdana, arial; font-size:14px;}.labelBox { stroke: #CCCCFF; fill: #ECECFF;}.labelText { fill:black; stroke:none; font-family: 'trebuchet ms', verdana, arial;}.loopText { fill:black; stroke:none; font-family: 'trebuchet ms', verdana, arial;}.loopLine { stroke-width:2; stroke-dasharray: "2 2"; marker-end:"url(#arrowhead)"; stroke: #CCCCFF;}.note { stroke: #decc93; stroke: #CCCCFF; fill: #fff5ad;}.noteText { fill:black; stroke:none; font-family: 'trebuchet ms', verdana, arial; font-size:14px;}

Configuration

Is it possible to adjust the margins for rendering the sequence diagram.

This is done by defining mermaid.sequenceConfig or by the CLI to use a json file with the configuration. How to use
the CLI is described in the mermaidCLI page.
mermaid.sequenceConfig can be set to a JSON string with config parameters or the corresponding object.

mermaid.sequenceConfig = { diagramMarginX:50, diagramMarginY:10, boxTextMargin:5, noteMargin:10, messageMargin:35, mirrorActors:true };

Possible configration params:

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.

Mermaid can render Gantt diagrams. The code snippet below:

%% Example of sequence diagramgantt title A Gantt Diagram section Section A task :a1, 2014-01-01, 30d Another task :after a1 , 20d section Another Task in sec :2014-01-12 , 12d anther task : 24d

Renders the following diagram:

gantt title A Gantt Diagram dateFormat YYYY-MM-DD section Section A task :a1, 2014-01-01, 30d Another task :after a1 , 20d section Another Task in sec :2014-01-12 , 12d anther task : 24d

Syntax

%% Example with slection of syntaxes 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 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

Renders like below:

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 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

title

Tbd

Sections statements

Tbd

Setting dates

Tbd

Date format

Tbd

Diagram definition

Input Example Description:

YYYY 2014 4 digit yearYY 14 2 digit yearQ 1..4 Quarter of year. Sets month to first month in quarter.M MM 1..12 Month numberMMM MMMM January..Dec Month name in locale set by moment.locale()D DD 1..31 Day of monthDo 1st..31st Day of month with ordinalDDD DDDD 1..365 Day of yearX 1410715640.579 Unix timestampx 1410715640579 Unix ms timestampInput Example DescriptionH HH 0..23 24 hour timeh hh 1..12 12 hour time used with a A.a A am pm Post or ante meridiemm mm 0..59 Minutess ss 0..59 SecondsS 0..9 Tenths of a secondSS 0..99 Hundreds of a secondSSS 0..999 Thousandths of a secondZ ZZ +12:00 Offset from UTC as +-HH:mm, +-HHmm, or Z

More info in: http://momentjs.com/docs/#/parsing/string-format/

Scale

%a - abbreviated weekday name.%A - full weekday name.%b - abbreviated month name.%B - full month name.%c - date and time, as "%a %b %e %H:%M:%S %Y".%d - zero-padded day of the month as a decimal number [01,31].%e - space-padded day of the month as a decimal number [ 1,31]; equivalent to %_d.%H - hour (24-hour clock) as a decimal number [00,23].%I - hour (12-hour clock) as a decimal number [01,12].%j - day of the year as a decimal number [001,366].%m - month as a decimal number [01,12].%M - minute as a decimal number [00,59].%L - milliseconds as a decimal number [000, 999].%p - either AM or PM.%S - second as a decimal number [00,61].%U - week number of the year (Sunday as the first day of the week) as a decimal number [00,53].%w - weekday as a decimal number [0(Sunday),6].%W - week number of the year (Monday as the first day of the week) as a decimal number [00,53].%x - date, as "%m/%d/%Y".%X - time, as "%H:%M:%S".%y - year without century as a decimal number [00,99].%Y - year with century as a decimal number.%Z - time zone offset, such as "-0700".%% - a literal "%" character.

More info in: https://github.com/mbostock/d3/wiki/Time-Formatting

Styling

Styling of the a sequence diagram is done by defining a number of css classes. During rendering these classes are extracted from the

Classes used

Sample stylesheet

 .grid .tick { stroke: lightgrey; opacity: 0.3; shape-rendering: crispEdges; } .grid path { stroke-width: 0; } #tag { color: white; background: #FA283D; width: 150px; position: absolute; display: none; padding:3px 6px; margin-left: -80px; font-size: 11px; } #tag:before { border: solid transparent; content: ' '; height: 0; left: 50%; margin-left: -5px; position: absolute; width: 0; border-width: 10px; border-bottom-color: #FA283D; top: -20px; } .taskText { fill:white; text-anchor:middle; } .taskTextOutsideRight { fill:black; text-anchor:start; } .taskTextOutsideLeft { fill:black; text-anchor:end; }

Configuration

Is it possible to adjust the margins for rendering the sequence diagram.

This is done by defining the sequenceConfig part of the configuration object. Read more about it here. How to use
the CLI is described in the mermaidCLI page.

Installing mermaid globally (npm install -g mermaid) will expose the mermaid command to your environment, allowing you to generate PNGs from any file containing mermaid markup via the command line.

Note: The mermaid command requires PhantomJS (version ^1.9.0) to be installed and available in your $PATH, or you can specify it's location with the -e option. For most environments, npm install -g phantomjs will satisfy this requirement.

Usage

$ mermaid --helpUsage: mermaid [options] ...file The mermaid description file to be renderedOptions: -s --svg Output SVG instead of PNG (experimental) -p --png If SVG was selected, and you also want PNG, set this flag -o --outputDir Directory to save files, will be created automatically, defaults to `cwd` -e --phantomPath Specify the path to the phantomjs executable -c --sequenceConfig Specify the path to the file with the configuration to be applied in the sequence diagram -h --help Show this message -v --verbose Show logging -w --width width of the generated png (number) --version Print version and quit

mermaid testGraph.mmdmermaid testGraph.mmd -w 980

Sequence diagram configuration

The --sequenceConfig option allows overriding the sequence diagram configuration. It could be useful to increase the width between actors, the notes width or the margin to fit some large texts that are not well rendered with the default configuration, for example.

The content of the file must be a JSON like this:

{ "diagramMarginX": 100, "diagramMarginY": 10, "actorMargin": 150, "width": 150, "height": 65, "boxMargin": 10, "boxTextMargin": 5, "noteMargin": 10, "messageMargin": 35}

These properties will override the default values and if a property is not set in this object, it will left it empty and could raise an error. The current properties (measured in px) are:

• diagramMarginX: Size of the empty space to add at the left-right of the diagram.
• diagramMarginY: Size of the empty space to add at the top-bottom of the diagram.
• actorMargin: Horizontal space between each participant. The arrows between them would have this size too.
• width: Width of the participant box.
• height: Height of the participant box.
• boxMargin: Blank area around loop boxes.
• boxTextMargin: Blank area between the text and the border in a loop box.
• noteMargin: Size of the empty space around a note.
• messageMargin: Space between messages

CLI Known Issues

• SVG output currently does some replacement on text, as mermaid's SVG output is only appropriate for browsers. Text color and background color is not yet replicated; please use PNGs for most purposes until this is resolved.
• SVG output is decidedly non-standard. It works, but may cause issues in some viewers.

Basic flowchart

%% Example diagramgraph 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

Larger flowchart with some styling

%% Code for flowchart belowgraph TB sq[Square shape] --> ci((Circle shape)) subgraph A subgraph 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

graph TB sq[Square shape] --> ci((Circle shape)) subgraph A subgraph 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
in an Odd shape] %% Comments after double percent signs e((Inner / circle
and some odd
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

Basic sequence diagram

%% Sequence diagram codesequenceDiagram 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?

Loops, alt and opt

%% Sequence diagram codesequenceDiagram loop Daily query Alice->>Bob: Hello Bob, how are you? alt is sick Bob->>Alice: Not so good :( else is well Bob->>Alice: Feeling fresh like a daisy end opt Extra response Bob->>Alice: Thanks for asking end end

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

Message to self in loop

%% Sequence diagram codesequenceDiagram 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!

This is the api to be used when handling the integration with the web page instead of using the default integration
(mermaid.js).

The core of this api is the render function that given a graph definitionas text renders the graph/diagram and
returns a svg element for the graph. It is is then up to the user of the API to make use of the svg, either insert it
somewhere in the page or something completely different.

Configuration

These are the default options which can be overridden with the initialization call as in the example below:

mermaid.initialize({ flowchart:{ htmlLabels: false }});

logLevel , decides the amount of logging to be used.

• debug: 1
• info: 2
• warn: 3
• error: 4
• fatal: 5
  cloneCssStyles - This options controls whether or not the css rules should be copied into the generated svg
  startOnLoad - This options controls whether or mermaid starts when the page loads
  arrowMarkerAbsolute - This options controls whether or arrow markers in html code will be absolute paths or
  an anchor, #. This matters if you are using base tag settings.

  flowchart

  The object containing configurations specific for flowcharts
  htmlLabels - Flag for setting whether or not a html tag should be used for rendering labels
  on the edges
  useMaxWidth - Flag for setting whether or not a all available width should be used for
  the diagram.

  sequenceDiagram

  The object containing configurations specific for sequence diagrams
  diagramMarginX - margin to the right and left of the sequence diagram
  diagramMarginY - margin to the over and under the sequence diagram
  actorMargin - Margin between actors
  width - Width of actor boxes
  height - Height of actor boxes
  boxMargin - Margin around loop boxes
  boxTextMargin - margin around the text in loop/alt/opt boxes
  noteMargin - margin around notes
  messageMargin - Space between messages
  mirrorActors - mirror actors under diagram
  bottomMarginAdj - Depending on css styling this might need adjustment.
  Prolongs the edge of the diagram downwards
  useMaxWidth - when this flag is set the height and width is set to 100% and is then scaling with the
  available space if not the absolute space required is used

  gantt

  The object containing configurations specific for gantt diagrams
  titleTopMargin - margin top for the text over the gantt diagram
  barHeight - the height of the bars in the graph
  barGap - the margin between the different activities in the gantt diagram
  topPadding - margin between title and gantt diagram and between axis and gantt diagram.
  leftPadding - the space allocated for the section name to the left of the activities.
  gridLineStartPadding - Vertical starting position of the grid lines
  fontSize - font size ...
  fontFamily - font family ...
  numberSectionStyles - the number of alternating section styles
  *axisFormatter - formatting of the axis, this might need adjustment to match your locale and preferences

  parse

  Function that parses a mermaid diagram definition. If parsing fails the parseError callback is called and an error is
  thrown and

  version

  Function returning version information
  ##render
  Function that renders an svg with a graph from a chart definition. Usage example below.

mermaidAPI.initialize({ startOnLoad:true }); $(function(){ var graphDefinition = 'graph TB\na-->b'; var cb = function(svgGraph){ console.log(svgGraph); }; mermaidAPI.render('id1',graphDefinition,cb); });

Updating the documentation

Getting the development environment up

1. Fork the gh-pages branch in the the mermaid repository
2. Do npm install

Working with the documentation

The html files are generated from the source and the markdown files in the docs folder. The site generation is done
using the docker.js framework with the command below.

docker -i ../mermaid/ -x "*git*|*travis*|*bin*|*dist*|*node_modules*|*gulp*|*lib*|*editor*|*conf*|*scripts*|*test*|*htmlDocs*" --extras mermaid -w -o htmlDocs

Thus ... One important thing to remember. Do not edit the html files directly! Those changes will be overwritten
when the site is re-generated.

Committing the changes

Do a pull request to merge the changes to the site.

Things to be done in order to add a new diagram type

Step 1: Grammar & Parsing

Grammar

This would be to define a jison grammar for the new diagram type. That should start with a way to identify that the text in the mermaid tag is a diagram of that type. Create a new folder under diagrams for your new diagram type and a parser folder in it. This leads us to step 2.

For instance:

• the flowchart starts with the keyword graph.
• the sequence diagram starts with the keyword sequenceDiagram

Store data found during parsing

There are some jison specific sub steps here where the parser stores the data encountered when parsing the diagram, this data is later used by the renderer. You can during the parsing call a object provided to the parser by the user of the parser. This object can be called during parsing for storing data.

statement : 'participant' actor { $$='actor'; } | signal { $$='signal'; } | note_statement { $$='note'; } | 'title' message { yy.setTitle($2); } ;

In the extract of the grammar above, it is defined that a call to the setTitle method in the data object will be done when parsing and the title keyword is encountered.

Note: Make sure that the parseError function for the parser is defined and calling mermaidPAI.parseError this way a common way of detecting parse errors is provided for the end-user.

For more info look in the example diagram type:

The yy object has the following function:

exports.parseError = function(err,hash){ mermaidAPI.parseError(err,hash);};

when parsing the yy object is initialized as per below:

 var parser; parser = exampleParser.parser; parser.yy = db;

Step 2: Rendering

Write a renderer that given the data found during parsing renders the diagram. To look at an example look at sequendeRenderer.js rather then the flowchart renderer as this is a more generic example.

Place the renderer in the diagram folder.

Step 3: Detection of the new diagram type

The second thing to do is to add the capability to detect the new new diagram to type to the detectType in utils.js. The detection should return a key for the new diagram type.

Step 4: The final piece - triggering the rendering

At this point when mermaid is trying to render the diagram, it will detect it as being of the new type but there will be no match when trying to render the diagram. To fix this add a new case in the switch statement in main.js:init this should match the diagram type returned from step number 2. The code in this new case statement should call the renderer for the diagram type with the data found by the parser as an argument.

Usage of the parser as a separate module

Setup

var graph = require('./graphDb');var flow = require('./parser/flow');flow.parser.yy = graph;

Parsing

flow.parser.parse(text);

Data extraction

// Javascript examplegraph.getDirection();graph.getVertices();graph.getEdges();

The parser is also exposed in the mermaid api by calling:

var parser = mermaid.getParser();

Note that the parse needs a graph object to store the data as per:

flow.parser.yy = graph;

Look at graphDb.js for more details on that object.

Some of the interfaces has been upgraded.

Initialization

mermaid_config is no longer used. Instead a call to mermaid initialize is done as in the example below:

version 0.4.0

mermaid_config = { startOnLoad:true };

will look like below in version 0.5.0

mermaid.initialize({ startOnLoad:true});