Creating and Building an App

Creating an App (enyo init)

Once you've completed the setup tasks outlined in First Steps with Enyo, you're ready to create an application. To initialize a project, use the enyo init command from the enyo-dev toolset. enyo init creates the standard Enyo directory structure and populates it with framework code and configuration files.

As an example, let's initialize a project called "my-project":

    enyo init my-project

enyo init, with the default template, provides us with the following directory structure:

        .enyoconfig    // Enyo configuration file
        .gitignore     // Git configuration file
        index.js       // The main source file
        lib/           // Enyo and its libraries
        package.json   // App and build configuration

Within the project directory (my-project), there are basic versions of several configuration files--.enyoconfig, .gitignore, and package.json. We also have the Enyo framework library, installed under my-project/lib/.

Before we continue, let's look briefly at package.json. Each app must contain a package.json file in its root directory. Here are the contents of the default package.json installed by enyo init:

    "name": "my-project",
    "main": "index.js",
    "assets": [],
    "styles": [],
    "devAssets": [],
    "moduleDir": "src"

package.json must contain a main key indicating the entry point for the application ("index.js" by default) and a name key with the project name. It may also include paths to assets and stylesheets, in the assets and styles arrays, respectively. The moduleDir key specifies the location of additional app source code; you will generally want to keep the default value, "src".

There are additional templates included with enyo-dev, to see a list use the following command:

enyo templates list

Filling Out the App Structure

You are now ready to complete the standard Enyo application structure by plugging in your own app-specific logic, assets, and so on:

        assets/        // Images and other resources for your app
        src/           // App source
        index.js       // App entry point

Most Enyo apps will have their logic stored in files under src/, but an app may be as simple as a single index.js file. To see for yourself, modify my-project/index.js to have the following contents:

    var Control = require('enyo/Control');
    var ready = require('enyo/ready');

    var HelloWorld = Control.kind({
        content: 'Hello, World!'

    ready(function () {
        new HelloWorld().renderInto(document.body);

In the next section, we'll learn how to turn this into a working "Hello, World!" app.

Building an App

As you develop your application, you'll want to (periodically) build the app for testing. The enyo-dev tools provide the enyo pack command for this.

enyo pack

enyo pack creates an optimized build of your application, using only the required source. The output, which includes the combined JavaScript as well as combined/compiled CSS/LESS, is written to ./dist by default; the output directory may be configured using the -d switch. The JavaScript and CSS may either be inlined in the HTML (the default for production) or, in development mode, stored in external files (via the --no-inline-css and --no-inline-js options). In addition, any assets declared in the app's package.json file will be copied to the output directory.

For example, the following command will create output in build/app.css and build/app.js.

    enyo pack --production -d ./build --no-inline-css --css-outfile app.css --no-inline-js --js-outfile app.js

Note that any enyo pack option available on the command line may also be set in the project's .enyoconfig file. Options specified on the command line will always override those defined in .enyoconfig.

The following .enyoconfig will produce the same output as the preceding command-line build, if enyo pack is run without any options:

    "production": true,
    "outDir": "./build",
    "inlineCss": false,
    "outCssFile": "app.css",
    "inlineJs": false,
    "outJsFile": "app.js"

You can try enyo pack for yourself using my-project and the index.js file from our example. Enter the my-project directory and run enyo pack. Then check out the built application under my-project/build.