class Mustache

Mustache is the base class from which your Mustache subclasses should inherit (though it can be used on its own).

The typical Mustache workflow is as follows:

Create a Mustache subclass: class Stats < Mustache
Create a template: stats.mustache
Instantiate an instance: view = Stats.new
Render that instance: view.render

You can skip the instantiation by calling `Stats.render` directly.

While Mustache will do its best to load and render a template for you, this process is completely customizable using a few options.

All settings can be overriden at the class level.

For example, going with the above example, we can use `Stats.template_path = “/usr/local/templates”` to specify the path Mustache uses to find templates.

Here are the available options:

::template_path

The `template_path` setting determines the path Mustache uses when looking for a template. By default it is “.” Setting it to /usr/local/templates, for example, means (given all other settings are default) a Mustache subclass `Stats` will try to load /usr/local/templates/stats.mustache

::template_extension

The `template_extension` is the extension Mustache uses when looking for template files. By default it is “mustache”

::template_file

You can tell Mustache exactly which template to use with this setting. It can be a relative or absolute path.

template

Sometimes you want Mustache to render a string, not a file. In those cases you may set the `template` setting. For example:

>> Mustache.render("Hello {{planet}}", :planet => "World!")
=> "Hello World!"

The `template` setting is also available on instances.

view = Mustache.new
view.template = "Hi, {{person}}!"
view[:person] = 'Mom'
view.render # => Hi, mom!

::view_namespace

To make life easy on those developing Mustache plugins for web frameworks or other libraries, Mustache will attempt to load view classes (i.e. Mustache subclasses) using the `view_class` class method. The `view_namespace` tells Mustache under which constant view classes live. By default it is `Object`.

::view_path

Similar to `template_path`, the `view_path` option tells Mustache where to look for files containing view classes when using the `view_class` method.

Settings which can be configured for all view classes, a single view class, or a single Mustache instance.

Constants

Enumerable
VERSION

Public Class Methods

partial(name) click to toggle source

Given a name, attempts to read a file and return the contents as a string. The file is not rendered, so it might contain {{mustaches}}.

Call `render` if you need to process it.

# File lib/mustache.rb, line 168
def self.partial(name)
  self.new.partial(name)
end

path() click to toggle source

Alias for `template_path`

# File lib/mustache/settings.rb, line 35
def self.path
  template_path
end

path=(path) click to toggle source

Alias for `template_path`

# File lib/mustache/settings.rb, line 40
def self.path=(path)
  self.template_path = path
end

raise_on_context_miss=(boolean) click to toggle source

# File lib/mustache/settings.rb, line 180
def self.raise_on_context_miss=(boolean)
  @raise_on_context_miss = boolean
end

raise_on_context_miss?() click to toggle source

Should an exception be raised when we cannot find a corresponding method or key in the current context? By default this is false to emulate ctemplate's behavior, but it may be useful to enable when debugging or developing.

If set to true and there is a context miss, `Mustache::ContextMiss` will be raised.

# File lib/mustache/settings.rb, line 176
def self.raise_on_context_miss?
  @raise_on_context_miss
end

render(*args) click to toggle source

Instantiates an instance of this class and calls `render` with the passed args.

@return A rendered String version of a template.

# File lib/mustache.rb, line 81
def self.render(*args)
  new.render(*args)
end

render_file(name, context = {}) click to toggle source

Given a file name and an optional context, attempts to load and render the file as a template.

# File lib/mustache.rb, line 153
def self.render_file(name, context = {})
  render(partial(name), context)
end

template() click to toggle source

The template is the actual string Mustache uses as its template. There is a bit of magic here: what we get back is actually a Mustache::Template object, but you can still safely use `template=`

with a string.

# File lib/mustache/settings.rb, line 140
def self.template
  @template ||= templateify(File.read(template_file))
end

template=(template) click to toggle source

# File lib/mustache/settings.rb, line 144
def self.template=(template)
  @template = templateify(template)
end

template_extension() click to toggle source

A Mustache template's default extension is 'mustache', but this can be changed.

# File lib/mustache/settings.rb, line 51
def self.template_extension
  @template_extension ||= inheritable_config_for :template_extension, 'mustache'
end

template_extension=(template_extension) click to toggle source

# File lib/mustache/settings.rb, line 55
def self.template_extension=(template_extension)
  @template_extension = template_extension
  @template = nil
end

template_file() click to toggle source

The template file is the absolute path of the file Mustache will use as its template. By default it's ./class_name.mustache

# File lib/mustache/settings.rb, line 110
def self.template_file
  @template_file || "#{path}/#{template_name}.#{template_extension}"
end

template_file=(template_file) click to toggle source

# File lib/mustache/settings.rb, line 114
def self.template_file=(template_file)
  @template_file = template_file
  @template = nil
end

template_name() click to toggle source

The template name is the Mustache template file without any extension or other information. Defaults to `class_name`.

You may want to change this if your class is named Stat but you want to re-use another template.

class Stat
  self.template_name = "graphs" # use graphs.mustache
end

# File lib/mustache/settings.rb, line 84
def self.template_name
  @template_name || underscore
end

template_name=(template_name) click to toggle source

# File lib/mustache/settings.rb, line 88
def self.template_name=(template_name)
  @template_name = template_name
  @template = nil
end

template_path() click to toggle source

The template path informs your Mustache view where to look for its corresponding template. By default it's the current directory (“.”)

A class named Stat with a ::template_path of “app/templates” will look for “app/templates/stat.mustache”

# File lib/mustache/settings.rb, line 15
def self.template_path
  @template_path ||= inheritable_config_for :template_path, '.'
end

template_path=(path) click to toggle source

# File lib/mustache/settings.rb, line 19
def self.template_path=(path)
  @template_path = File.expand_path(path)
  @template = nil
end

view_namespace() click to toggle source

The constant under which Mustache will look for views when autoloading. By default the view namespace is `Object`, but it might be nice to set it to something like `Hurl::Views` if your app's main namespace is `Hurl`.

# File lib/mustache/settings.rb, line 202
def self.view_namespace
  @view_namespace ||= inheritable_config_for(:view_namespace, Object)
end

view_namespace=(namespace) click to toggle source

# File lib/mustache/settings.rb, line 206
def self.view_namespace=(namespace)
  @view_namespace = namespace
end

view_path() click to toggle source

Mustache searches the view path for .rb files to require when asked to find a view class. Defaults to “.”

# File lib/mustache/settings.rb, line 218
def self.view_path
  @view_path ||= inheritable_config_for(:view_path, '.')
end

view_path=(path) click to toggle source

# File lib/mustache/settings.rb, line 222
def self.view_path=(path)
  @view_path = path
end

Private Class Methods

classify(underscored) click to toggle source

template_partial => TemplatePartial template/partial => Template::Partial

# File lib/mustache.rb, line 256
def self.classify(underscored)
  Mustache::Utils::String.new(underscored).classify
end

compiled?() click to toggle source

Has this template already been compiled? Compilation is somewhat expensive so it may be useful to check this before attempting it.

# File lib/mustache.rb, line 249
def self.compiled?
  @template.is_a? Template
end

const_from_file(name) click to toggle source

# File lib/mustache.rb, line 237
def self.const_from_file name
  file_name = underscore(name)
  file_path = "#{view_path}/#{file_name}.rb"

  return Mustache unless File.exists?(file_path)

  require file_path.chomp('.rb')
  rescued_const_get(name)
end

inheritable_config_for(attr_name, default) click to toggle source

Return the value of the configuration setting on the superclass, or return the default.

@param [Symbol] attr_name Name of the attribute. It should match

the instance variable.

@param [Object] default Default value to use if the superclass does

not respond.

@return Inherited or default configuration setting.

# File lib/mustache.rb, line 287
def self.inheritable_config_for(attr_name, default)
  superclass.respond_to?(attr_name) ? superclass.send(attr_name) : default
end

rescued_const_get(name) click to toggle source

# File lib/mustache.rb, line 231
def self.rescued_const_get name
  const_get(name, true) || Mustache
rescue NameError
  nil
end

templateify(obj) click to toggle source

@param [Template,String] obj Turns `obj` into a template

# File lib/mustache.rb, line 270
def self.templateify(obj)
  obj.is_a?(Template) ? obj : Template.new(obj)
end

underscore(classified = name) click to toggle source

TemplatePartial => template_partial

Template::Partial => template/partial Takes a string but defaults to using the current class' name.

# File lib/mustache.rb, line 263
def self.underscore(classified = name)
  classified = superclass.name if classified.to_s.empty?

  Mustache::Utils::String.new(classified).underscore(view_namespace)
end

view_class(name) click to toggle source

When given a symbol or string representing a class, will try to produce an appropriate view class. e.g.

Mustache.view_namespace = Hurl::Views
Mustache.view_class(:Partial) # => Hurl::Views::Partial

# File lib/mustache.rb, line 217
def self.view_class(name)
  name = classify(name.to_s)

  # Emptiness begets emptiness.
  return Mustache if name.to_s.empty?

  name = "#{view_namespace}::#{name}"
  const = rescued_const_get(name)

  return const if const

  const_from_file(name)
end

Public Instance Methods

[](key) click to toggle source

Context accessors.

Example:

view = Mustache.new
view[:name] = "Jon"
view.template = "Hi, {{name}}!"
view.render # => "Hi, Jon!"

# File lib/mustache.rb, line 136
def [](key)
  context[key.to_sym]
end

[]=(key, value) click to toggle source

# File lib/mustache.rb, line 140
def []=(key, value)
  context[key.to_sym] = value
end

compiled?() click to toggle source

Has this instance or its class already compiled a template?

# File lib/mustache.rb, line 204
def compiled?
  (@template && @template.is_a?(Template)) || self.class.compiled?
end

context() click to toggle source

A helper method which gives access to the context at a given time. Kind of a hack for now, but useful when you're in an iterating section and want access to the hash currently being iterated over.

# File lib/mustache.rb, line 147
def context
  @context ||= Context.new(self)
end

escapeHTML(str) click to toggle source

Override this to provide custom escaping.

Example:

class PersonView < Mustache
  def escapeHTML(str)
    my_html_escape_method(str)
  end
end

@param [String] str String to escape.

@return [String] Escaped HTML.

# File lib/mustache.rb, line 199
def escapeHTML(str)
  CGI.escapeHTML(str)
end

partial(name) click to toggle source

Override this in your subclass if you want to do fun things like reading templates from a database. It will be rendered by the context, so all you need to do is return a string.

# File lib/mustache.rb, line 175
def partial(name)
  path = "#{template_path}/#{name}.#{template_extension}"

  begin
    File.read(path)
  rescue
    raise if raise_on_context_miss?
    ""
  end
end

path()

Alias for: template_path

raise_on_context_miss=(boolean) click to toggle source

# File lib/mustache/settings.rb, line 189
def raise_on_context_miss=(boolean)
  @raise_on_context_miss = boolean
end

raise_on_context_miss?() click to toggle source

Instance level version of `Mustache.raise_on_context_miss?`

# File lib/mustache/settings.rb, line 185
def raise_on_context_miss?
  self.class.raise_on_context_miss? || @raise_on_context_miss
end

render(data = template, ctx = {}) click to toggle source

Parses our fancy pants template file and returns normal file with all special {{tags}} and {{#sections}}replaced{{/sections}}.

Examples

@view.render("Hi {{thing}}!", :thing => :world)

View.template = "Hi {{thing}}!"
@view = View.new
@view.render(:thing => :world)

@param [String,Hash] data A String template or a Hash context.

If a Hash is given, we'll try to figure
out the template from the class.

@param [Hash] ctx A Hash context if `data` is a String template.

@return [String] Returns a rendered version of a template.

# File lib/mustache.rb, line 102
def render(data = template, ctx = {})
  case data
  when Hash
    ctx = data
  when Symbol
    self.template_name = data
  end

  tpl = case data
  when Hash
    templateify(template)
  when Symbol
    templateify(template)
  else
    templateify(data)
  end

  return tpl.render(context) if ctx == {}

  begin
    context.push(ctx)
    tpl.render(context)
  ensure
    context.pop
  end
end