mustache -- Logic-less templates.
A typical Mustache template:
Hello {{name}}
You have just won ${{value}}!
{{#in_ca}}
Well, ${{taxed_value}}, after taxes.
{{/in_ca}}
Given the following hash:
{
"name": "Chris",
"value": 10000,
"taxed_value": 10000 - (10000 * 0.4),
"in_ca": true
}
Will produce the following:
Hello Chris
You have just won $10000!
Well, $6000.0, after taxes.
Mustache can be used for HTML, config files, source code - anything. It works by expanding tags in a template using values provided in a hash or object.
We call it "logic-less" because there are no if statements, else clauses, or for loops. Instead there are only tags. Some tags are replaced with a value, some nothing, and others a series of values. This document explains the different types of Mustache tags.
Tags are indicated by the double mustaches. {{name}} is a tag. Let's
talk about the different types of tags.
The most basic tag is the variable. A {{name}} tag in a basic
template will try to call the name method on your view. If there is
no name method, an exception will be raised.
All variables are HTML escaped by default. If you want to return
unescaped HTML, use the triple mustache: {{{name}}}.
You can also use & to unescape a variable: {{& name}}. This may be
useful when changing delimiters (see "Set Delimter" below).
By default a variable "miss" returns an empty string. This can usually be configured in your Mustache library.
Template:
* {{name}}
* {{age}}
* {{company}}
* {{{company}}}
Hash:
{
"name": "Chris",
"company": "<b>GitHub</b>"
}
Output:
* Chris
*
* <b>GitHub</b>
* <b>GitHub</b>
A section begins with a pound and ends with a slash. That is,
{{#person}} begins a "person" section while {{/person}} ends it.
If the person key exists and calling it returns false, the HTML
between the pound and slash will not be displayed.
If the person method exists and calling it returns true, the HTML
between the pound and slash will be rendered and displayed.
Template:
{{#person}}
Shown!
{{/person}}
{{#anything_else}}
Never shown!
{{/anything_else}}
Hash:
{
"person": true
}
Output:
Shown!
Enumerable sections are syntactically identical to boolean sections in that they begin with a pound and end with a slash. The difference, however, is in the view: if the method called returns an enumerable, the section is repeated as the enumerable is iterated over.
Each item in the enumerable is expected to be a hash which will then become the context of the corresponding iteration. In this way we can construct loops.
Template:
{{#repo}}
<b>{{name}}</b>
{{/repo}}
Hash:
{
"repo": [
{ "name": "resque" },
{ "name": "hub" },
{ "name": "rip" },
]
}
Output:
<b>resque</b>
<b>hub</b>
<b>rip</b>
Comments begin with a bang and are ignored. The following template:
<h1>Today{{! ignore me }}.</h1>
Will render as follows:
<h1>Today.</h1>
Partials begin with a greater than sign, like {{> box}}.
It is useful to think of partials as a "template expansion" - that is, the actual partial tag will be replaced with the content of the partial. Therefor partials share the current context.
For example, this template and partial:
base.mustache:
<h2>Names</h2>
{{# names }}
{{> user }}
{{/ names }}
user.mustache:
<strong>{{ name }}</strong>
Can be thought of as a single, expanded template:
<h2>Names</h2>
{{# names }}
<strong>{{ name }}</strong>
{{/ names }}
Set Delimiter tags start with an equal sign and change the tag delimiters from {{ and }} to custom strings.
Consider the following contrived example:
* {{ default_tags }}
{{=<% %>=}}
* <% erb_style_tags %>
<%={{ }}=%>
* {{ default_tags_again }}
Here we have a list with three items. The first item uses the default tag style, the second uses erb style as defined by the Set Delimiter tag, and the third returns to the default style after yet another Set Delimiter declaration.
According to ctemplates, this "is useful for languages like TeX, where double-braces may occur in the text and are awkward to use for markup."
Custom delimiters may not contain whitespace or the equals sign.
Mustache is Copyright (C) 2009 Chris Wanstrath
Original CTemplate by Google
mustache(1), mustache(7), gem(1), http://defunkt.github.com/mustache/