# Electron Documentation Style Guide

These are the guidelines for writing Electron documentation.

## Titles

* Each page must have a single `#`-level title at the top.
* Chapters in the same page must have `##`-level titles.
* Sub-chapters need to increase the number of `#` in the title according to
  their nesting depth.
* All words in the page's title must be capitalized, except for conjunctions
  like "of" and "and" .
* Only the first word of a chapter title must be capitalized.

Using `Quick Start` as example:

```markdown
# Quick Start

...

## Main process

...

## Renderer process

...

## Run your app

...

### Run as a distribution

...

### Manually downloaded Electron binary

...
```

For API references, there are exceptions to this rule.

## Markdown rules

* Use `sh` instead of `cmd` in code blocks (due to the syntax highlighter).
* Lines should be wrapped at 80 columns.
* No nesting lists more than 2 levels (due to the markdown renderer).
* All `js` and `javascript` code blocks are linted with
[standard-markdown](https://www.npmjs.com/package/standard-markdown).

## Picking words

* Use "will" over "would" when describing outcomes.
* Prefer "in the ___ process" over "on".

## API references

The following rules only apply to the documentation of APIs.

### Page title

Each page must use the actual object name returned by `require('electron')`
as the title, such as `BrowserWindow`, `autoUpdater`, and `session`.

Under the page title must be a one-line description starting with `>`.

Using `session` as example:

```markdown
# session

> Manage browser sessions, cookies, cache, proxy settings, etc.
```

### Module methods and events

For modules that are not classes, their methods and events must be listed under
the `## Methods` and `## Events` chapters.

Using `autoUpdater` as an example:

```markdown
# autoUpdater

## Events

### Event: 'error'

## Methods

### `autoUpdater.setFeedURL(url[, requestHeaders])`
```

### Classes

* API classes or classes that are part of modules must be listed under a
  `## Class: TheClassName` chapter.
* One page can have multiple classes.
* Constructors must be listed with `###`-level titles.
* [Static Methods](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes/static) must be listed under a `### Static Methods` chapter.
* [Instance Methods](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Classes#Prototype_methods) must be listed under an `### Instance Methods` chapter.
* All methods that have a return value must start their description with "Returns `[TYPE]` - Return description"
  * If the method returns an `Object`, its structure can be specified using a colon followed by a newline then an unordered list of properties in the same style as function parameters.
* Instance Events must be listed under an `### Instance Events` chapter.
* Instance Properties must be listed under an `### Instance Properties` chapter.
  * Instance properties must start with "A [Property Type] ..."

Using the `Session` and `Cookies` classes as an example:

```markdown
# session

## Methods

### session.fromPartition(partition)

## Static Properties

### session.defaultSession

## Class: Session

### Instance Events

#### Event: 'will-download'

### Instance Methods

#### `ses.getCacheSize()`

### Instance Properties

#### `ses.cookies`

## Class: Cookies

### Instance Methods

#### `cookies.get(filter, callback)`
```

### Methods

The methods chapter must be in the following form:

```markdown
### `objectName.methodName(required[, optional]))`

* `required` String - A parameter description.
* `optional` Integer (optional) - Another parameter description.

...
```

The title can be `###` or `####`-levels depending on whether it is a method of
a module or a class.

For modules, the `objectName` is the module's name. For classes, it must be the
name of the instance of the class, and must not be the same as the module's
name.

For example, the methods of the `Session` class under the `session` module must
use `ses` as the `objectName`.

The optional arguments are notated by square brackets `[]` surrounding the optional argument
as well as the comma required if this optional argument follows another
argument:

```sh
required[, optional]
```

Below the method is more detailed information on each of the arguments. The type
of argument is notated by either the common types:

* [`String`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String)
* [`Number`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number)
* [`Object`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object)
* [`Array`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array)
* [`Boolean`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Boolean)
* Or a custom type like Electron's [`WebContent`](api/web-contents.md)

If an argument or a method is unique to certain platforms, those platforms are
denoted using a space-delimited italicized list following the datatype. Values
can be `macOS`, `Windows` or `Linux`.

```markdown
* `animate` Boolean (optional) _macOS_ _Windows_ - Animate the thing.
```

`Array` type arguments must specify what elements the array may include in
the description below.

The description for `Function` type arguments should make it clear how it may be
called and list the types of the parameters that will be passed to it.

### Events

The events chapter must be in following form:

```markdown
### Event: 'wake-up'

Returns:

* `time` String

...
```

The title can be `###` or `####`-levels depending on whether it is an event of
a module or a class.

The arguments of an event follow the same rules as methods.

### Properties

The properties chapter must be in following form:

```markdown
### session.defaultSession

...
```

The title can be `###` or `####`-levels depending on whether it is a property of
a module or a class.

## Documentation Translations

See [electron/i18n](https://github.com/electron/i18n#readme)
