Module: Haml::Filters

Extended by:
Filters
Included in:
Filters
Defined in:
lib/haml/filters.rb,
lib/haml/sass_rails_filter.rb

Overview

The module containing the default Haml filters, as well as the base module, Base.

See Also:

Defined Under Namespace

Modules: Base, Cdata, Coffee, Css, Erb, Escaped, Javascript, Less, Markdown, Plain, Preserve, Ruby, Sass, Scss Classes: SassRailsTemplate, ScssRailsTemplate

Instance Attribute Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#defined ⇒ {String => Haml::Filters::Base} (readonly)

Returns a hash mapping filter names to classes.

Returns:

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# File 'lib/haml/filters.rb', line 16

def defined
  @defined
end

Instance Method Details

#register_tilt_filter(name, options = {}) ⇒ Module

Loads an external template engine from Tilt as a filter. This method is used internally by Haml to set up filters for Sass, SCSS, Less, Coffeescript, and others. It’s left public to make it easy for developers to add their own Tilt-based filters if they choose.

Parameters:

  • options (Hash) (defaults to: {}) —

    Options for generating the filter module.

Options Hash (options):

  • :precompiled (Boolean) —

    Whether the filter should be precompiled. Erb, Nokogiri and Builder use this, for example.

  • :template_class (Class) —

    The Tilt template class to use, in the event it can’t be inferred from an extension.

  • :extension (String) —

    The extension associated with the content, for example “markdown”. This lets Tilt choose the preferred engine when there are more than one.

  • :alias (String, Array<String>) —

    Any aliases for the filter. For example, :coffee is also available as :coffeescript.

  • :extend (String) —

    The name of a module to extend when defining the filter. Defaults to “Plain”. This allows filters such as Coffee to “inherit” from Javascript, wrapping its output in script tags.

Returns:

  • (Module) —

    The generated filter.

Since:

  • 4.0

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# File 'lib/haml/filters.rb', line 40

def register_tilt_filter(name, options = {})
  if constants.map(&:to_s).include?(name.to_s)
    raise "#{name} filter already defined"
  end

  filter = const_set(name, Module.new)
  filter.extend const_get(options[:extend] || "Plain")
  filter.extend TiltFilter
  filter.extend PrecompiledTiltFilter if options.has_key? :precompiled

  if options.has_key? :template_class
    filter.template_class = options[:template_class]
  else
    filter.tilt_extension = options.fetch(:extension) { name.downcase }
  end

  # All ":coffeescript" as alias for ":coffee", etc.
  if options.has_key?(:alias)
    [options[:alias]].flatten.each {|x| Filters.defined[x.to_s] = filter}
  end
  filter
end

#remove_filter(name)

Removes a filter from Haml. If the filter was removed, it returns the Module that was removed upon success, or nil on failure. If you try to redefine a filter, Haml will raise an error. Use this method first to explicitly remove the filter before redefining it.

Returns:

  • Module The filter module that has been removed

Since:

  • 4.0

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# File 'lib/haml/filters.rb', line 69

def remove_filter(name)
  defined.delete name.to_s.downcase
  if constants.map(&:to_s).include?(name.to_s)
    remove_const name.to_sym
  end
end