Utopia

Utopia is a website generation framework which provides a robust set of tools to build highly complex dynamic websites. It uses the filesystem heavily for content and provides functions for interacting with files and directories as structure representing the website.

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Motivation

The original Utopia project was written in PHP in the early 2000s. It consisted of an XML parser, a database layer and some code to assist with business logic. It was initially designed to reduce the amount of HTML required to build both content-centric websites and business apps. At the time, CSS was very poorly supported and thus a lot of the time, you'd be using quite complex <table>s with embedded <img>s to generate simple things like boxes with drop shadows, etc. Utopia provided a core concept - a node - which was essentially a small snippet of HTML, which could be composed into other nodes simply by using a named tag (similar to ColdFusion). Attributes and content were passed in, and thus you could easily build complex pages with simple semantic markup.

At the time, the available frameworks were pretty basic. Utopia was a working, albeit poor, implementation of MVC and supported several commercial websites I developed at the time. I made it, partly just because I could, but also because it served a commercial purpose.

Eventually one day I started using Ruby on Rails. There are aspects of the Rails framework which I like. However, at the time I was using it (starting with version 0.8), I found that it's flat organisation of controllers and views very limiting. Nested controllers and views make it easier to manage complexity in a web application. Utopia embraces this principle, and applies it to both the controller and view layers. I also developed a model layer with similar principles.

So, Utopia exists because it suits my way of thinking about web applications, and it's conceptual core has been refined for over a decade. It provides a considered amount of both flexibility, and opinionated behavior.

Installation

Local Setup

Install utopia:

$ gem install utopia

Create a new site:

$ mkdir www.example.com
$ cd www.example.com
$ utopia site create
$ rake

Bower Integration

If you create a site using the utopia generator, it includes a .bowerrc configuration which installs components into public/_static/components. To install jquery, for example:

$ bower install jquery

Then add the appropriate <script> tags to pages/_page.xnode:

<script src="/_static/components/jquery/dist/jquery.min.js" type="text/javascript"></script>

Server Setup

Utopia can be used to set up remote sites quickly and easily.

Firstly log into your remote site using ssh and install utopia:

$ ssh remote
$ sudo gem install utopia

Then use the utopia command to generate a new remote site:

$ mkdir /srv/http/www.example.com
$ cd /srv/http/www.example.com
$ sudo -u http utopia server create

On the local site, you can set up a git remote:

$ git remote add production ssh://remote/srv/http/www.example.com
$ git push --set-upstream production master

When you push to the remote site, rake deploy will be run after the code is updated, finally, rake restart will be run which ideally should restart the application server.

Passenger+Nginx Setup

Utopia works well with Passenger+Nginx. Installing Passenger+Nginx is easy:

$ ssh remote
$ sudo gem install passenger
$ passenger-install-nginx-module

Then, Nginx is configured like so:

server {
    listen 80;
    server_name www.example.com;
    root /srv/http/www.example.com/public;
    passenger_enabled on;
}

server {
    listen 80;
    server_name example.com;
    rewrite ^ http://www.example.com$uri permanent;
}

Arch Linux

Packages for deploying Passenger+Nginx on Arch are available in the AUR. There are issues with the official packages so please avoid them.

Compression

We suggest enabling gzip compression:

gzip on;
gzip_vary on;
gzip_comp_level 6;
gzip_http_version 1.1;
gzip_proxied any;
gzip_types text/* image/svg+xml application/json application/javascript;

Usage

Utopia builds on top of Rack with the following middleware:

  • Utopia::Static: Serve static files efficiently.
  • Utopia::Redirection: Redirect URL patterns and status codes.
  • Utopia::Localization: Non-intrusive localization of resources.
  • Utopia::Controller: Dynamic behaviour with recursive execution.
  • Utopia::Content: XML-style template engine with powerful tag behaviours.
  • Utopia::Session: Session storage using an encrypted cookie.

The implementation of Utopia is considered thread-safe and reentrant. However, this does not guarantee that the code YOU write will be so.

Static

This middleware serves static files using the mime-types library. By default, it works with Rack::Sendfile and supports ETag based caching. Normally, you'd prefer to put static files into public/_static but it's also acceptable to put static content into pages/ if it makes sense.

use Utopia::Static,
    # The root path to serve files from:
    root: "path/to/root",
    # The mime-types to recognize/serve:
    types: [:default, :xiph],
    # Cache-Control header for files:
    cache_control: 'public, max-age=7200'

Redirection

A set of flexible URI rewriting middleware which includes support for string mappings, regular expressions and status codes (e.g. 404 errors).

# String (fast hash lookup) rewriting:
use Utopia::Redirection::Rewrite,
    '/' => '/welcome/index'

# Redirect directories (e.g. /) to an index file (e.g. /index):
use Utopia::Redirection::DirectoryIndex,
    index: 'index.html'

# Redirect (error) status codes to actual pages:
use Utopia::Redirection::Errors,
    404 => '/errors/file-not-found'

Localization

The localization middleware uses the Accept-Language header to guess the preferred locale out of the given options. If a request path maps to a resource, that resource is returned. Otherwise, a localized request is made.

use Utopia::Localization,
    :default_locale => 'en',
    :locales => ['en', 'de', 'ja', 'zh'],
    :nonlocalized => ['/_static/', '/_cache/']

Somewhere further down the chain, you can localize a resource:

localization = Utopia::Localization[request]
show_welcome(localization.current_locale)

Controller

A simple recursive controller layer which works in isolation from the view rendering middleware.

use Utopia::Controller,
    # The root directory where `controller.rb` files can be found.
    root: 'path/to/root',
    # The base class to use for all controllers:
    base: Utopia::Controller::Base
    # Whether or not to cache controller classes:
    cache_controllers: (RACK_ENV == :production),

A controller is a file within the root directory (or subdirectory) with the name controller.rb. This code is dynamically loaded into an anonymous class and executed. The default controller has only a single function:

def passthrough(request, path)
    # Call one of:

    # This will cause the middleware to generate a response.
    # def respond!(response)

    # This will cause the controller to skip the request.
    # def ignore!

    # Request relative redirect. Respond with a redirect to the given target.
    # def redirect! (target, status = 302)

    # Controller relative redirect.
    # def goto!(target, status = 302)

    # Respond with an error which indiciates some kind of failure.
    # def fail!(error = 400, message = nil)

    # Succeed the request and immediately respond.
    # def succeed!(status: 200, headers: {}, **options)
    # options may include content: string or body: Enumerable (as per Rack specifications
end

The controller layer can do more complex operations by prepending modules into it.

prepend Rewrite, Actions

# Extracts an Integer
rewrite.extract_prefix id: Integer do
    @user = User.find_by_id(@id)
end

before do |request, path|
    # Always executed, before any controller specific actions are performed.
end

on 'edit' do |request, path|
    if request.post?
        @user.update_attributes(request[:user])
    end
end

otherwise do |request, path|
    # Executed if no specific named actions were executed.
end

after do |request, path|
    # Always executed, after all other controller actions are performed.
end

Content

A tag based content generation system which integrates nicely with HTML5. Supports structures which separate generic page templates from dynamically generated content in an easy and consistent way.

use Utopia::Content,
    cache_templates: (RACK_ENV == :production),
    tags: {
        'deferred' => Utopia::Tags::Deferred,
        'override' => Utopia::Tags::Override,
        'node' => Utopia::Tags::Node,
        'environment' => Utopia::Tags::Environment.for(RACK_ENV)
    }

A basic template create.xnode looks something like:

<page>
    <heading>Create User</heading>
    <form action="#">
        <input name="name" />
        <input type="submit" />
    </form>
</page>

This template would typically be designed with supporting _page.xnode and _heading.xnode in the same directory or, more typically, somewhere further up the directory hierarchy.

Session

The session management uses symmetric private key encryption to store data on the client and avoid tampering.

use Utopia::Session,
    :expires_after => 3600,
    :secret => '40 or more random characters for your secret key'

All session data is stored on the client, but it's encrypted with a salt and the secret key. It would be hard for the client to decrypt the data without the secret.

Testing

Utopia websites include a default set of tests, and associated rake test tasks. These specs can test against the actual running website. By default, simplecov is included for coverage testing.

$ rake coverage test

my website
    should have an accessible front page

Finished in 0.44849 seconds (files took 0.15547 seconds to load)
1 example, 0 failures

Coverage report generated for RSpec. 5 / 5 LOC (100.0%) covered.

Contributing

  1. Fork it
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create new Pull Request

License

Released under the MIT license.

Copyright, 2015, by Samuel G. D. Williams.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.