Inspired by ctemplate and et, Mustache is a framework-agnostic way to render logic-free views.
As ctemplates says, "It emphasizes separating logic from presentation: it is impossible to embed application logic in this template language."
For a list of implementations (other than Ruby) and tips, see http://mustache.github.com/.
Think of Mustache as a replacement for your views. Instead of views consisting of ERB or HAML with random helpers and arbitrary logic, your views are broken into two parts: a Ruby class and an HTML template.
We call the Ruby class the "view" and the HTML template the "template."
All your logic, decisions, and code is contained in your view. All your markup is contained in your template. The template does nothing but reference methods in your view.
This strict separation makes it easier to write clean templates, easier to test your views, and more fun to work on your app's front end.
I like writing Ruby. I like writing HTML. I like writing JavaScript.
I don't like writing ERB, Haml, Liquid, Django Templates, putting Ruby in my HTML, or putting JavaScript in my HTML.
Quick example:
>> require 'mustache'
=> true
>> Mustache.render("Hello {{planet}}", :planet => "World!")
=> "Hello World!"
We've got an examples folder but here's the canonical one:
class Simple < Mustache
def name
"Chris"
end
def value
10_000
end
def taxed_value
value * 0.6
end
def in_ca
true
end
end
We simply create a normal Ruby class and define methods. Some methods reference others, some return values, some return only booleans.
Now let's write the template:
Hello {{name}}
You have just won {{value}} dollars!
{{#in_ca}}
Well, {{taxed_value}} dollars, after taxes.
{{/in_ca}}
This template references our view methods. To bring it all together, here's the code to render actual HTML;
Simple.render
Which returns the following:
Hello Chris
You have just won 10000 dollars!
Well, 6000.0 dollars, after taxes.
Simple.
For a language-agnostic overview of Mustache's template syntax, see
the mustache(5) manpage or
http://mustache.github.com/mustache.5.html.
Mustache does escape all values when using the standard double
Mustache syntax. Characters which will be escaped: & \ " < >. To
disable escaping, simply use triple mustaches like
{{{unescaped_variable}}}.
Example: Using {{variable}} inside a template for 5 > 2 will
result in 5 > 2, where as the usage of {{{variable}}} will
result in 5 > 2.
ctemplate and friends want you to hand a dictionary to the template processor. Mustache supports a similar concept. Feel free to mix the class-based and this more procedural style at your leisure.
Given this template (winner.mustache):
Hello {{name}}
You have just won {{value}} bucks!
We can fill in the values at will:
view = Winner.new
view[:name] = 'George'
view[:value] = 100
view.render
Which returns:
Hello George
You have just won 100 bucks!
We can re-use the same object, too:
view[:name] = 'Tony'
view.render
Hello Tony
You have just won 100 bucks!
A word on templates. By default, a view will try to find its template on disk by searching for an HTML file in the current directory that follows the classic Ruby naming convention.
TemplatePartial => ./template_partial.mustache
You can set the search path using Mustache.template_path. It can be set on a
class by class basis:
class Simple < Mustache
self.template_path = File.dirname(__FILE__)
... etc ...
end
Now Simple will look for simple.mustache in the directory it resides
in, no matter the cwd.
If you want to just change what template is used you can set
Mustache.template_file directly:
Simple.template_file = './blah.mustache'
Mustache also allows you to define the extension it'll use.
Simple.template_extension = 'xml'
Given all other defaults, the above line will cause Mustache to look for './blah.xml'
Feel free to set the template directly:
Simple.template = 'Hi {{person}}!'
Or set a different template for a single instance:
Simple.new.template = 'Hi {{person}}!'
Whatever works.
Mustache supports a bit of magic when it comes to views. If you're
authoring a plugin or extension for a web framework (Sinatra, Rails,
etc), check out the view_namespace and view_path settings on the
Mustache class. They will surely provide needed assistance.
What about global helpers? Maybe you have a nifty gravatar function
you want to use in all your views? No problem.
This is just Ruby, after all.
module ViewHelpers
def gravatar
gravatar_id = Digest::MD5.hexdigest(self[:email].to_s.strip.downcase)
gravatar_for_id(gravatar_id)
end
def gravatar_for_id(gid, size = 30)
"#{gravatar_host}/avatar/#{gid}?s=#{size}"
end
def gravatar_host
@ssl ? 'https://secure.gravatar.com' : 'http://www.gravatar.com'
end
end
Then just include it:
class Simple < Mustache
include ViewHelpers
def name
"Chris"
end
def value
10_000
end
def taxed_value
value * 0.6
end
def in_ca
true
end
def users
User.all
end
end
Great, but what about that @ssl ivar in gravatar_host? There are
many ways we can go about setting it.
Here's an example which illustrates a key feature of Mustache: you
are free to use the initialize method just as you would in any
normal class.
class Simple < Mustache
include ViewHelpers
def initialize(ssl = false)
@ssl = ssl
end
... etc ...
end
Now:
Simple.new(request.ssl?).render
Finally, our template might look like this:
<ul>
{{# users}}
<li><img src="{{ gravatar }}"> {{ login }}</li>
{{/ users}}
</ul>
Mustache ships with Sinatra integration. Please see
lib/mustache/sinatra.rb or
http://github.com/defunkt/mustache/blob/master/lib/mustache/sinatra.rb
for complete documentation.
An example Sinatra application is also provided: http://github.com/defunkt/mustache-sinatra-example
If you are upgrading to Sinatra 1.0 and Mustache 0.9.0+ from Mustache 0.7.0 or lower, the settings have changed. But not that much.
See this diff for what you need to
do. Basically, things are named properly now and all should be
contained in a hash set using set :mustache, hash.
Mustache also ships with a Rack::Bug panel. In your config.ru add
the following code:
require 'rack/bug/panels/mustache_panel'
use Rack::Bug::MustachePanel
Using Rails? Add this to your initializer or environment file:
require 'rack/bug/panels/mustache_panel'
config.middleware.use "Rack::Bug::MustachePanel"
Thanks to Juvenn Woo for mustache.vim. It is included under the contrib/ directory.
See http://gist.github.com/323622 for installation instructions.
mustache-mode.el is available at https://github.com/mustache/emacs
See http://gist.github.com/323624 for installation instructions.
See mustache(1) man page or
http://mustache.github.com/mustache.1.html
for command line docs.
$ gem install mustache
Thanks to Tom Preston-Werner for showing me ctemplate and Leah Culver for the name "Mustache."
Special thanks to Magnus Holm for all his awesome work on Mustache's parser.
Once you've made your great commits:
- Fork Mustache
- Create a topic branch -
git checkout -b my_branch - Push to your branch -
git push origin my_branch - Create an Issue with a link to your branch
- That's it!
You might want to checkout Resque's Contributing wiki page for information on coding standards, new features, etc.
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The archive can be found at http://librelist.com/browser/.
- Code:
git clone git://github.com/defunkt/mustache.git - Home: http://mustache.github.com
- Bugs: http://github.com/defunkt/mustache/issues
- List: [email protected]
- Gems: http://rubygems.org/gems/mustache
You can also find us in #{ on irc.freenode.net.