Lineman is a tool to help you build fat-client webapp projects. It requires node.js & npm and wouldn't be possible without grunt.
For an overview, consider checking out the demo screencast!
Suppose that you're starting a new single page web application and you want to reap the benefits of loose coupling between your client-side and server side. If that rings true, then Lineman (and similar tools) can help to keep you as productive working in the front-end as traditional HTML generation frameworks do on the back-end.
Now, for the features!
Lineman is a productivity tool, in that it provides a development server which:
- Serves up your app on a local development server at localhost:8000
- Compiles your CoffeeScript into JavaScript as soon as you save a file
- Immediately compiles your Sass and Less into CSS
- Provides tools to stub out your back-end API services with express
- Compiles your JavaScript templates (e.g. Underscore, Handlebars) to a
window.JSTobject that maps their file path to the compiled template function - Can ease development by proxying XHRs to your server-side app
- Features a delightful spec runner called Testem, which comes pre-configured for Jasmine
Lineman is also a build tool, because when you're ready to deploy:
- You can deploy to Heroku just by committing and pushing with git
- Assemble your app into a portable
distdirectory with minified JavaScript & CSS, which can in turn be deployed wherever static assets are served
At the end of the day, Lineman is just a handful of conventions and grunt task configurations that can help you get up-and-running more quickly than rolling your own. It's easy to extend and modify as your application grows.
First, you'll need node.js. If you plan on running tests, you'll also want PhantomJS somewhere on your PATH. (This is where the aforementioned screencast picks up.)
Next, you'll need to install Lineman globally:
$ npm install -g linemanOnce Lineman is installed, you can either ask it to generate a new project for you, or you might consider cloning from a pre-existing template.
To create a new project, run the lineman binary with the new command and tell it where you'd like the project to go:
$ lineman new my-projectThis will create a new directory named "my-project" and copy in Lineman's archetypal project.
We have a few template projects floating around to help you get up-and-running even more faster.
- Using Backbone.js
- Using Angular.js
- Using Ember.js
- Building a Markdown blog
To see all of the options available to you in the terminal use the -h or --help option:
$ lineman --helpFrom the project directory, you can start a server at localhost:8000:
$ lineman runInternally, Grunt's watch task will monitor for file changes; in turn, Lineman's default configuration will fire the appropriate tasks when a file of a given type is saved.
With any luck, visiting the server in your browser will yield something as beautiful as this:
The Hello World code shows off JST compilation, CoffeeScript, and Less. When you edit a source file, your changes are usually reflected by the time you can refresh your browser.
Lineman has a very narrow focus: helping you build client-side apps as a collection of ready-to-deploy static assets. That said, almost all nontrivial client-side apps require some interaction with a server, and no developer could be expected to write working code without either faking the server-side or plugging the client and server together. Lineman offers support for both!
Users may define custom HTTP services to aid development in config/server.js by exporting a function named drawRoutes. Here's a trivial example:
module.exports = {
drawRoutes: function(app) {
app.get('/api/greeting/:message', function(req, res){
res.json({ message: "OK, "+req.params.message });
});
}
};With this definition in place, if the client-side app makes a request to "/api/greeting/ahoy!", this route will handle the request and return some JSON.
Because Lineman uses express for the development server, please reference its documentation for details on all the nifty things you can do.
Lineman also provides a facility to forward any requests that it doesn't know how to respond to a proxy service. Typically, if you're developing a client-side app in Lineman and intend to pair it to a server-side app (written, say, in Ruby on Rails), you could run a local Rails server on port 3000 while running Lineman, and your JavaScript could seamlessly send requests to Rails on the same port as Lineman's development server.
To enable proxying, set the enabled flag on the apiProxy configuration of the server task in config/application.js, like this:
server: {
apiProxy: {
enabled: true,
port: 3000
}
}With this feature, you'll be able to develop your client-side and server-side code in concert, while still keeping the codebases cleanly separated.
Lineman provides a way to direct requests to either the apiProxy or serve up generated/index.html in order to simulate what using HTML5 pushState will behave like when running in dev mode. This requires both apiProxy.prefix and server.pushState configuration property to be set, so that the apiProxy correctly knows how route requests to the api you have configured. To enable pushState in your application set the pushState flag on the server task in config/application.js and the prefix on the apiProxy configuration of the server task, like this:
server: {
// enables HTML5 pushState; Lineman will correctly serve `generated/index.html` for any request that does not match the apiProxy.prefix
pushState: true,
apiProxy: {
enabled: true,
port: 3000,
prefix: 'api' // any requests that contain 'api' will now be the only ones forwarded to the apiProxy
}
}[Note: enabling server.pushState merely configures the apiProxy to be smart about routing, you will still need to configure pushState support in whichever client-side routing library you are using.]
Lineman provides a way to run your specs constantly as you work on your code with the lineman spec command:
$ lineman spec[Note: lineman spec requires lineman run to be running in a different process to monitor file changes..
The spec command will launch the fantastic test framework Testem supports Safari, Chrome, Firefox, Opera, PhantomJS and (IE9, IE8, IE7 if on Windows). By default we have configured Testem to launch Chrome for tests during development.
You can override this by modifying the launch_in_dev property within config/spec.json
We have found that running tests in Chrome during development is ideal as it enables the insertion of debugger; statements into javascript which allows debugging in the browser.
You can also run specs with output generated for your CI environment in TAP 13 format:
$ lineman spec-ciThis configuration executes specs headlessly using only PhantomJS. You can override this by modifying the launch_in_ci property within config/spec.json
When you're ready to send your application off to a remote server, just run the lineman build task.
$ lineman buildThe above runs a task that produces a production-ready web application in the project's dist/ directory.
To clean the two build directories (dist and generated), just run the clean task:
$ lineman cleanLineman generates a very particular directory structure. It looks like this:
.
├── app
│ ├── js # <-- JS & CoffeeScript
│ ├── img # <-- images (are merged into the 'img' folder inside of generated & dist)
│ └── templates # <-- client-side templates
│ ├── homepage.us # <-- a template used to produce the application's index.html
│ ├── other.us # <-- other templates will be compiled to a window.JST object
│ └── thing.hb # <-- underscore & handlebars are both already set up
│ └── _partial.hb # <-- a handlebars partial, usable from within other handlebars templates
├── config
│ ├── application.js # <-- Override application configuration
│ ├── files.js # <-- Override named file patterns
│ ├── server.js # <-- Define custom server-side endpoints to aid in development
│ └── spec.json # <-- Override spec run configurations
├── dist # <-- Generated, production-ready app assets
├── generated # <-- Generated, pre-production app assets
├── grunt.js # <-- gruntfile defines app's task config
├── package.json # <-- Project's package.json
├── tasks # <-- Custom grunt tasks can be defined here
├── spec
│ ├── helpers # <-- Spec helpers (loaded before other specs)
│ └── some-spec.coffee # <-- All the Jasmine specs you can write (JS or Coffee)
└── vendor # <-- 3rd-party assets will be prepended or merged into the application
├── js # <-- 3rd-party Javascript
│ └── underscore.js # <-- Underscore, because underscore is fantastic.
├── img # <-- 3rd-party images (are merged into the 'img' folder inside of generated & dist)
└── css # <-- 3rd-party CSS
The lineman run command keeps file handles on all your projects files at once. If you're seeing a message that looks like this:
undefined: [Lundefined:Cundefined] EMFILE, too many open files
Or this
Error: watch Unknown system errno 23
Then it probably means your project has gotten big enough to either run into the user limit on open file descriptors or (in the case of the latter), the hard limit on your operating system's file table .
To resolve this issue, we recommend first increasing the user limit on open files with the ulimit command. You might do this at the beginning of any terminal session or in your ~/.profile dotfile.
ulimit -n 2048
The great thing about a tool whose focus is narrowly on HTML, CSS, and JavaScript is that's all you have to worry about when it comes time to deploy. When you're ready to deploy, just run:
$ lineman build
And this will place a version of your app with minified assets that's ready to be deployed wherever you like. Maybe you'll plan on integrating it with your server-side's existing deployment, or maybe you'll host the files on a static file server.
Deploying your app to heroku couldn't be easier. Once you have the heroku toolbelt installed, simply run this from your project:
heroku create --stack cedar --buildpack http://github.com/testdouble/heroku-buildpack-lineman.git
Now, whenever you git push heroku, our custom buildpack will build your project with lineman and then start serving your minified site assets with apache!
What's really neat about this workflow is that while heroku takes care of building the assets for you (meaning you don't have to worry about checking in or transferring any generated assets), at runtime node is nowhere to be found! Your site is just static assets running on apache.
Lineman got its name from finding that the word "grunt" was first used to describe unskilled railroad workers. Grunts that made the cut were promoted to linemen.
Most fat-client web applications are still written as second-class denizens within server-side project directories. This has inhibited the formation of a coherent community of people who write applications HTML, CSS, and JavaScript, because the server-side technology is dominant. Front-end work on a Rails project differs greatly from front-end work on a Java project, even though they're building the same thing!
All we wanted was a cozy & productive application development tool that didn't saddle our client-side code with a particular server-side technology. Intentionally dividing backend and front-end projects applies a healthy pressure to decouple the two.
It doesn't hurt that with Lineman, we're able to bootstrap new client-side apps faster than we ever have before.
Lineman was created by test double, a software studio in Columbus, Ohio. It's distributed under the MIT license.
If you're interested in contributing to Lineman, it's probably worth knowing how to run Lineman's tests. It's a little tricky, because we're using Ruby & RSpec to integration-test a node project.
Once you've cloned lineman, here's all you need to install lineman's dependencies and the run its tests.
$ npm install
$ cd test
$ bundle install
$ bundle exec rspec