Mustache (template system)

Mustache is a simple web template system with implementations available for ActionScript, C++, Clojure, CoffeeScript, ColdFusion, Common Lisp, D, Delphi, Erlang, Fantom, Go, Haskell, Io, Java, JavaScript, Julia, Lua, .NET, Objective-C, Perl, PHP, Pharo, Python, Racket, Ruby, Rust, Scala, Swift, CFEngine and XQuery.

Mustache is described as a "logic-less" system because it lacks any explicit control flow statements, like if and else conditionals or for loops; however, both looping and conditional evaluation can be achieved using section tags processing lists and lambdas.

It is named "Mustache" because of heavy use of curly braces ,{ }, that resemble a sideways moustache.

Mustache is used mainly for mobile and web applications.^[1][2]

History and principles

Mustache-1 was inspired by ctemplate and et,^[3] and started as a GitHub distribution at the end of 2009. A first version of the template engine was implemented with Ruby, running YAML template texts. The (preserved) main principles were:

• "logic-less": no explicit control flow statements, all control driven by data.
• strong "separating logic from presentation": it is impossible to embed application logic in the Mustache templates.

The input data can be a class, so input data can be characterized as an MVC-view. The Mustache template does nothing but reference methods in the (input data) view.^[3] All the logic, decisions, and code is contained in this view, and all the markup (ex. output XML) is contained in the template. In an MVP context: input data is from MVP-presenter, and the Mustache template is the MVP-view.

Examples

The simplest template:

Hello {{name}}

Template with section tag:

{{#x}}
Some text
{{/x}}

Here, when x is a Boolean value then the section tag acts like an if conditional, but when x is an array then it acts like a foreach loop.

Template that is not escaped:

{{&body}}

Here, if body contains HTML, it won't be escaped.

Technical details

Syntax highlighting is available in Vim, Emacs,^[4] TextMate, Coda and Atom.

The Mustache templates support is built into many web application frameworks (ex. CakePHP). The support in JavaScript includes both client-side programming with many popular JavaScript libraries and Ajax frameworks like jQuery, Dojo and YUI, as well as server-side JavaScript using Node.js and CommonJS.

Specification and implementations

There are many Mustache Engine implementations available, and all of them meet a common specification (see external links) — that for final users results in the common syntax.

As of March 2011, the last SPEC_VERSION was 1.1.2.^[5]

All Mustache Engines, in the v1.X architecture, have a render method, a Mustache_Compiler class and a Parser class.

References

External links

• Official website
• Mustache syntax
• Mustache spec