Class: Stylish::Rule

Inherits:
Object
  • Object
show all
Includes:
Formattable, Tree::Leaf
Defined in:
lib/stylish/core.rb

Overview

Rule objects represent CSS rules, and serialise to them. They possess one or more selectors, and zero or more declarations. In addition to their importance as the major building-blocks of stylesheets, they act as the leaves of Stylish’s stylesheet trees.

Their serialisation is controllable to some extent by altering their format attribute; this should never make them lose information when they are serialised.

E.g., by changing its format to “%s %sn” a rule that would normally be serialised thus:

body {font-size:81%;}

Would instead be serialised like this:

body {
  font-size:81%;
}

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from Formattable

included

Methods included from Tree::Leaf

#leaf?

Methods included from Tree::Node

#leaf?, #root?

Constructor Details

#initialize(selectors, declarations) ⇒ Rule

Every Rule must have at least one selector, but may have any number of declarations. Empty rules are often used in stylesheets to indicate particular combinations of selectors which may be used to produce particular effects.

In Stylish, of course, a Rule’s declarations may be amended after its creation:

rule = Stylish::Rule.new([Stylish::Selector.new("body")])
rule.declarations << Stylish::Declaration.new("font-weight", "bold")
rule.to_s # => "body {font-weight:bold;}"

This makes Rule objects a very flexible foundation for the higher-level data structures and APIs in Stylish.



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# File 'lib/stylish/core.rb', line 82

def initialize(selectors, declarations)
  @selectors = selectors.inject(Selectors.new) do |ss, s|
    ss << s
  end
  
  @declarations = declarations.inject(Declarations.new) do |ds, d|
    ds << d
  end
end

Instance Attribute Details

#declarations ⇒ Object (readonly)

Returns the value of attribute declarations.



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# File 'lib/stylish/core.rb', line 65

def declarations
  @declarations
end

#selectors ⇒ Object (readonly)

Returns the value of attribute selectors.



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# File 'lib/stylish/core.rb', line 65

def selectors
  @selectors
end

Instance Method Details

#to_s(symbols = {}, scope = "") ⇒ Object

Serialise the rule to valid CSS code.



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# File 'lib/stylish/core.rb', line 93

def to_s(symbols = {}, scope = "")
  sprintf(self.class.format, selectors.join(symbols, scope),
    @declarations.to_s(symbols))
end