Sequence Diagrams for HTML

This is a set of stylesheets for displaying sequence diagrams in HTML pages.

You can write in semantic markup (demo page) or pure CSS (demo page) - be sure to look at the source.

To embed in your page, you'll need sequence-diagram.css, plus either the conversion script or an extra CSS file for columns.

Pure CSS (includes layout)

The underlying markup works by separating everything into columns and adding CSS classes (e.g. col-2-4 for column 2 in a 4-column layout). If you're doing the layout manually (pure CSS option), you'll need to include sequence-diagram-columns.css.

However, you shouldn't have to write this layout code yourself, instead writing the semantic markup.

Semantic markup

The diagram can be entered in a more intuitive way (no layout concerns). To automatically convert, include the convert.js script, and place the diagram markup in a <sequence-diagram-semantic> element. You do not need the column CSS, because the conversion script generates CSS as needed.

All elements in the semantic markup can be used either directly (i.e. <sequence-diagram-semantic>) or declared by the corresponding CSS class (i.e. <div class="sequence-diagram-semantic">).

Declaring entities

Entities are declared with a <header> element. Each entity is an <entity> element, with an optional alias attribute specifying how it will be referred to later.

<sequence-diagram-semantic>
	<header>
		<entity>Alice</entity>
		<entity>Bob</entity>
		<entity>Carol</entity>
		<entity alias="cat">Dani's cat</entity>
	</header>
	...
</sequence-diagram-semantic>

Actions

Actions are declared with a <action> element.

The source/target of the action can be specified either with <to>/<from> elements, or to/from properties, depending on whether they're part of the content or not:

<sequence-diagram-semantic>
	<header>...</header>
	<action><from>Alice</from> asks <to>Bob</to> a question</action>
	<action from="Bob" to="Alice">reply</action>
</sequence-diagram-semantic>

Notes and events

Notes and events are declared with <note> or <event> elements.

As with <action>s, to/from (attributes or elements) can be used to span the event between two entities. However, <for> (or the for= attribute) can be used to place associate the note/event with a single entity.

Conversion from text

Also included is a (fairly hacky) convertor that takes in a simple text format and outputs HTML:

Alice --> Carol: say hello
Carol: (notes go here)
Dani: some event

See more at the live demo.