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Leafdoc (or 🍂doc for short) is a NaturalDocs- and JSdoc-like documentation generator.

Leafdoc's goals are to help produce documentation which is:

  • Concise: If you need half a page to describe what a function does, then Leafdoc is probably not for you.
  • Non-intrusive: Allow devs to write the minimum possible amount of documentation lines. A two-line function shouldn't need 15 lines of docs.
  • Narrative: Forget about exhaustive code introspection, and focus into providing freeform human-readable explanations and per-class code examples using Markdown to do the heavy lifting.
  • Language-agnostic: Designed with Javascript in mind (and its dozens of ways of doing class inheritance or defining methods), Leafdoc doesn't parse your source code, just the comments.


See Leafdoc's own documentation as generated by Leafdoc, or the Leaflet documentation as generated by Leafdoc.

Try it yourself

git clone [...]
npm install
npm test

You will find a Leafdoc.html file. Open that file in a web browser, and you'll see Leafdoc's own documentation.

Command-line usage

npm install leafdoc
node_modules/.bin/leafdoc -t node_modules/leafdoc/templates/basic -o documentation.html src

See Leafdoc's own documentation for a reference of available parameters.


The syntax is pretty much the tried-and-true directives-in-comment-blocks from JSdoc, NaturalDocs and a gazillion others. But instead of an @ symbol, Leafdoc uses a leaf:

 * 🍂method addDir: this
 * 🍂param dirname: String
 * 🍂param extension: String
 * Recursively scans a directory, and parses any files that match the given `extension`

Leafdoc was designed with compactness in mind, so it accepts comment blocks consisting of adjacent // comment lines, and a shorthand syntax for function/method parameters. This is equivalent to the example just above:

// 🍂method addDir (dirname: String, extension: String): this
// Recursively scans a directory, and parses any files that match the given `extension`

If you need to be even more compact, use a semicolon (;) to put several directives in the same line:

// 🍂namespace Math; 🍂method sum(a: Int, b: Int): Int ; Returns the sum of two numbers

Valid directives

  • 🍂class and 🍂namespace should be at the top of your files. They define the context of the rest of the directives. A namespace can be used in more than one file (for example, when plugging more functionality to an existing class).

  • 🍂example lets some space to demonstrate how the class / namespace is meant to be used.

  • 🍂section allows you to group several functions, events, methods or options together, thematically. You may need to have sections without an explicit name to add stuff to the default section.

  • Methods, functions, options, etc are a generic thing internally named "documentable":

    • 🍂method
    • 🍂function
    • 🍂factory
    • 🍂constructor
    • 🍂destructor
    • 🍂option
    • 🍂event
    • 🍂example
    • 🍂property
  • Functions/methods/factories can have parameters, specified with 🍂param (name), 🍂param (name): (type) or inline (see below).

  • Classes, namespaces and documentables can have 🍂aka (alternative name), (short for Also Known As). This allows to create links to the same thing using different names.

  • Anything can have several 🍂comments, explaining the thing. 🍂comment directives can be implicit, because any (non-empty) line without an explicit directive equals to a comment.

  • If a function (or any other documentable) has several alternative uses, use the 🍂alternative directive after to re-defining the documentable, e.g.:

    🍂method on(type: String, fn: Function): this
    Adds the function `fn` as an event handler for the `type` event.
    🍂method on(types: [String], fn: Function): this
    Given an array of event types (strings), attaches `fn` as an event handler to each of them.

    In this example, the two alternatives are on(type, fn) and on(fnMap). They will be shown as two different documentables.

  • 🍂inherits [parent] means that a class or namespace inherits all documentables from another class or namespace.

  • 🍂relationship [relationshiptype] [namespace] () is specific to thegraphviz

  • 🍂uninheritable is applied only to sections, and hides them from the

  • 🍂miniclass [name] [(parentname)] defines a class/namespace that shall display inside the parent namespace (specified between parentheses); most useful for very concide classes/data structs that are useful only within the context of the parent namespace.

Shorthand syntax

Any documentable has the same syntax: name, optional required flag, optional parameters, optional type / return type/value, default value.

name[?] [ ( params ) ] [: type] [= default]

where params is

name[?] [ : type ]  [ , name[?] [ : type ]  [ , name[?] [ : type ] ...  ]   ]

and where name is a valid unicode identifier, or an ellipsis (). type and default are freeform and can have spaces.

Which means the following are possible:

An option usually has a type and a default value:
🍂option enabled: Boolean = true

But we can omit the default value:
🍂option enabled: Boolean

Or omit just the data type:
🍂option enabled = true

Or even just say there is an option:
🍂option enabled

A function with a return type:
🍂function get: String

A function with one parameter:
🍂function get(id: Int): String

Or two:
A function with one parameter:
🍂function sum(a: Int, b: Int): Int

The last function can also be written without the parameters shorthand:
🍂function sum: Int
🍂param a: Int
🍂param b: Int

Use an interrogation sign to specify a parameter as optional:
🍂function update(force? : Boolean): null

Use ellipsis to mark optional parameters:
🍂function update(…): null

You can specify everything (name, optional, params, type, default), but no documentable uses them all in the templates. The usual schema is:

Params Type Default
option X X
property X X
event X
method X X
function X X
factory X
constructor X
factory X

Relationships format

Relationships are meaningful for class diagrams. They correspond with the UML class diagram

The syntax is:

🍂relationship type namespace [ ,cardinalityFrom [ ,cardinalityTo [ ,label ]]]

The following relationship types are implemented for display in the graphviz-class-diagram templates:

  • associated
  • implements
  • dependsOn
  • aggregationOf
  • compositionOf

Note that class inheritance is a separate directive (🍂inherits) .

namespace must be an identifier; cardinalityFrom and cardinalityTo must not have commas in them.

Some examples of how 🍂relationship works:

🍂namespace ConcreteClass
🍂relationship implements AbstractClass
🍂namespace Classroom
🍂relationship aggregationOf Student, 0..n, 1..n
🍂relationship aggregationOf Teacher, 1, 0..n
🍂namespace Caller
🍂relationship associated Callee ,, calls

Output customization

The output relies on a set of handlebars templates. By default, the ones in templates/basic will be used. In order to use another set of templates, pass the templateDir` option to the Leafdoc constructor, like so:

var l = new Leafdoc({templateDir: 'leaflet'});

I will write no detailed docs on how to modify the templates. If you know some HTML and handlebars, just copy them and hack things away :-)

Custom documentables

Your code might have several things of the same kind, which you want to show in the same fashion as documentables. Maybe it's files, or icons, or you have 5 trivial sub-classes which only merit one line.

You can define custom documentables by doing so:

var l = new Leafdoc();
l.registerDocumentable('icon', 'Available icons');

Whenever you add a custom documentable, you'll need to create its handlebars template too! Failure to do so will throw an error when you are building your documentation.

Your custom documentable will accept parameters, type, and default as the rest of documentables, and can follow the shorthand syntax. You will have to map parameters, type and default to something that makes sense for that documentable. For example, the template might map an icon's filename to the documentable's default:

🍂icon happy = 'icons/happy.gif'
A happy face

Also documentables can be inheritable or not. For example you have some entities in namespace which can be inherited. Pass true to third argument of registerDocumentable to make documentable inheritable:

var l = new Leafdoc();
l.registerDocumentable('field', 'Fields', true);

And later in your documentation:

🍂field limit? = 5
A limit for query

Known gotchas

  • Leafdoc relies on some ugly per-module globals, so having more than one instance in your code (in the same process) might break things up. The use case for Leafdoc is to have just one instance when building docs for your code.


Licensed under the GNU General Public License version 3 (or "GPL3"). Check the full text at


I'm using Debian and I cannot see the leaf character!

Run apt-get install fonts-symbola.

I cannot type 🍂 in my keyboard!

(Linux only) Write this into a plain text file:

keycode  46 = l L l L U1F342 Lstroke lstroke

Then run xmodmap name-of-the-file. Now 🍂 is mapped to AltGr+l.

Of course, you can always do leafdoc.setLeadingCharacter('@');, but that's boring.


A lightweight NaturalDocs-like LeafletJS-style documentation generator






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