Emo-gen NPM | npm.io

emo-gen

A node style-guide generator

Installation

npm install emo-gen --save-dev

Overview

emo-gen aids in the developemnt of style-guides, providing a slim API by which a style-guide may be generated. emo-gen uses the Nunjucks.js template engine.

Usage (API)

After intalling emo-gen, you may include it in your project like so.

var StyleGuideGenerator = require('emo-gen');

emo-gen exposes the StyleGuideGenerator class, which makes available a number of methods.

StyleGuideGenerator(options, nunjucksOptions)

The StyleGuideGenerator constructor accepts two parameters (options and nunjucksOptions).

options:

path (Object): an object containing a src and/or dest property
- src (String): the location where the style-guide source code is to be placed
- dest (String): the location where the style-guide will build to

nunjucksOptions: see nunjuck's options for more information

Default options:

StyleGuideGenerator.OPTIONS = {
    path: {
        src: 'styleguide/src/',  // default
        dest: 'styleguide/dest/' // default
    }
};

styleGuideGenerator.place()

Place the style-guide source in the location specified by styleGuideGenerator.options.path.src. Note that this method looks for an index.html file in the specified source location. If it finds one, the style-guide source files will not be placed; otherwise, they will be. styleGuideGenerator.place must run before styleGuideGenerator.build.

The place method returns a promise.

Example:

styleGuideGenerator.place().then(function() {
    // do something
});

styleGuideGenerator.copy(files)

Copy the provided files. files must be an array containing src-dest files mappings. copy returns a promise.

var files = [{
    src: 'web/assets/styles/app.css',
    dest: 'styleguide/dest/assets/styles/app.css'
}];

styleGuideGenerator.copy(files).then(function() {
    // yay, files copied!
});

styleGuideGenerator.build(componentFiles, viewDir)

Build the style-guide from the provided parameters. The componentFiles parameter must be a list of files and/or glob patterns (e.g., ['src/assets/scss/**']). The viewDir parameter must be a relative path from the root of the style-guide source directory (styleguide/src/ by default). emo-gen will treat all the .html files within the viewDir as static pages, building each one via the Nunjucks api.

Example:

var componentFiles = [
    'src/assets/scss/*.scss',
    'src/assets/scripts/*.js',
    'src/index.html'
];

var viewDir = 'views';

styleGuideGenerator.build(componentFiles, viewDir).then(function() {
    // the style-guide was built!
});

A complete example

var componentFiles = ['src/assets/scss/**/*.scss'];
var filesToCopy = [{
    src: 'web/assets/styles/app.css',
    dest: 'styleguide/dest/assets/styles/app.css'
}];
var styleGuideGenerator = new StyleGuideGenerator();

styleGuideGenerator.place().then(function() {
    return styleGuideGenerator.copy(filesToCopy).then(function() {
        return styleGuideGenerator.build(componentFiles);
    }));
});

Documentation Syntax

emo-gen was made to scrape documentation from source files. Within a given source file, documentation is expected to be written as YAML front mattter. Example documentation follows.

/*

---
name: Btn
category: Content
description: <button>I'm a button!<button>
---

 */

.btn { ... }

Loading External Documenation

Because writing a bunch of documentation in your source files isn't fun, emo-gen makes it possible to load external documentation from markdown files. Note that the specified path should be relative to the file in which it was written.

/*

---
name: Btn
category: Content
description: relative/path/to/btn_docs.md 
---

 */

.btn { ... }

Eliminate the Need for Doc Blocks

emo-gen also allows you to lose the need for documentation blocks altogether. To do so, simply add your doc blocks to the markdown files themselves and tell emo-gen to scrape them, like so var componentFile = ['src/assets/scss/**/*.md'];.

---
name: Btn
category: Content
---

Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod
tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam

<button>I'm a button</button>

Note that when emo-gen is scraping .md files, it will ignore the description value of the YAML front matter block. In its place, emo-gen will instead use the remaining content of the .md file as the value of the description property.

Doc Block Requirements

emo-gen expects that all components use a name, category, and description property; if a component does not use these properties, it will not show up in the style-guide. The description property will be used as the main body of a given component's documentation. Beyond these properties, emo-gen will allow you to add properties as you wish.

/*

---
name: Btn
category: Content
version: 1.0.0
author: Some Person
description: relative/path/to/btn_docs.md
---

 */

.btn { ... }

Additional properties will be available in the component template via the component global. For example, the author property added above may be rendered in the component template like so.

{{ component.author }}

Nunjucks in Markdown

emo-gen exposes the Nunjucks API to the markdown files it processes. This allows documentation authors to load partials, macros, and use oher Nunjucks goodness in your documentation.

Imagine you create a macro for a card component.

<!-- in styleguide/src/macros/card.html -->

{% macro card(title, body) %}
<div class="card">
    <div class="card-hd">{{ title }}</div>
    <div class="card-bd">{{ body }}</div>
    <div class="card-ft">
        <button type="button" class="btn">read more</button>
    </div>
</div>
{% endmacro %}

Now, you want to document the card, so you create a mardown file. Since emo-gen exposes Nunjucks to markdown files, you can do this.

---
name: Card
category: Molecules
---

<!-- this path must be relative from the root of the style-guide source directory -->
{% import 'macros/card.html' as macros %}

Lorem ipsum dolor sit amet, consectetur adipisicing elit. Assumenda mollitia aspernatur id ipsam dolorem, quos quasi rem ad sunt nemo eaque est illo et, quisquam, natus veniam fugit magnam minus.

<div class="sg-example">
    {{ macros.card('Lorem ipsum.', 'Lorem ipsum dolor sit amet, consectetur adipisicing elit. Nostrum magnam autem fugiat aperiam omnis! Itaque animi dicta veniam dolore neque alias rem distinctio, laborum commodi.') }}
</div>

See the Nunjucks API referrence to learn more about you can do with Nunjucks.

The Source Files

The style-guide source directory contains the following.

----/styleguide/src/              <- default style-guide source directory
--------/assets/
------------/styles/
----------------/styleguide.css   <- the style-guide's styles
--------/layouts/
------------/default.html         <- swig layouts (see http://goo.gl/fD39tI)
--------/partials/
------------/_nav.html            <- the main navigation (renders component list)
--------/templates/
------------/component.html       <- the default component template
--------/index.html               <- the style-guide's homepage

The Build

The style-guide destination folder will look as such.

----/styleguide/dest/             <- default style-guide dest directory
--------/assets/
------------/styles/
----------------/styleguide.css   <- the style-guide's styles
----------------/app.css          <- styles copied over
--------/category/                <- each category gets its own folder
------------/btn.html             <- each component gets its own file
------------/other-category/
------------/box.html
------------/card.html
--------/third-category/
------------/anchor.html
--------/index.html               <- the style-guide's homepage

The Build Process

For each component category found in your source file(s), emo-gen will create a new folder; within the nav, categories will be listed in alphabetical order. One .html file will be created for each component.

Consider the following documention block.

/*

---
name: Btn
category: Content
description: relative/path/to/btn_docs.md
---

 */

.btn { ... }

The previous doc block will generate the following structure within the style-guide destination.

----/styleguide/dest/
--------/Content/
------------/Btn.html

Using a Custom Template

By default, components are built against the components.html template found in the style-guide src templates folder. To use a custom template, simply provide a template property in your doc block. The value of said property should be a relative path from the root of the style-guide src folder.

Example:

/*

---
name: Btn
category: Content
template: templates/custom.html
description: relative/path/to/btn_docs.md
---

 */

.btn { ... }

Using a Custom Filename

By default, emo-gen will use a component's name property to construct its filename. Consider the following doc block.

/*

---
name: Btn
category: Content
description: relative/path/to/btn_docs.md
---

 */

.btn { ... }

The previous documentation will generate the following structure.

----/styleguide/dest/
--------/Content/
------------/Btn.html             <- notice how I'm named after my name

To change this default, apply a filename property to your doc block. Like so:

/*

---
name: Btn
category: Content
filename: custom.html
description: relative/path/to/btn_docs.md
---

 */

.btn { ... }

The View Models

During the build process (styleGuideGenerator.build()), three models are exposed to the templates: one to index.html, another to the component templates, and a third to the views.

The Homepage (`index.html`) Model

var data = {
    pathToRoot: '',           // a relative path to the index.html file
    components: components,   // a list of all the components,
    views: views              // a list of all the views
};

The Component Model

This model is exposed to each component template as the style-guide is being built.

var data = {
    pathToRoot: '../',        // a relative path to the index.html file
    component: component,     // the current component
    components: components,   // a list of all the components,
    views: views              // a list of all the views
};

A Word on the `component` Property.

The component property will mirror the same model as the doc block that was used to create it.

Example:

/*

---
name: Btn
category: Content
author: Some Person
color: red
number: 20
description: relative/path/to/btn_docs.md
---

 */

.btn { ... }

The previous doc block will generate the following component model.

var component = {
    name: 'Btn',
    category: 'Content',
    author: 'Some Person',
    color: 'red',
    number: 20,
    description: '<button>/<button>'  // the contents of relative/path/to/btn_docs.md
};

This data is available to the templates via the component global.

The View Model

This model is exposed to each view as the style-guide is being built.

var data = {
    pathToRoot: '../',        // a relative path to the index.html file
    view: view,               // the current view
    components: components,   // a list of all the components,
    views: views              // a list of all the views
};