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#!/usr/bin/env ruby
#--
# Copyright 2004, 2005 by Jim Weirich (jim@weirichhouse.org).
# Copyright 2005 by Scott Barron (scott@elitists.net).
# All rights reserved.
#
# Permission is granted for use, copying, modification, distribution,
# and distribution of modified versions of this work as long as the
# above copyright notice is included.
#
# Much of this is taken from Jim's work in xmlbase.rb and xmlmarkup.rb.
# Documentation has also been copied and pasted and modified to reflect
# that we're building CSS here instead of XML. Jim is conducting the
# orchestra here and I'm just off in the corner playing a flute.
#++
# Provide a flexible and easy to use Builder for creating Cascading
# Style Sheets (CSS).
require 'builder/blankslate'
module Builder
# Create a Cascading Style Sheet (CSS) using Ruby.
#
# Example usage:
#
# css = Builder::CSS.new
#
# text_color = '#7F7F7F'
# preferred_fonts = 'Helvetica, Arial, sans_serif'
#
# css.comment! 'This is our stylesheet'
# css.body {
# background_color '#FAFAFA'
# font_size 'small'
# font_family preferred_fonts
# color text_color
# }
#
# css.id!('navbar') {
# width '500px'
# }
#
# css.class!('navitem') {
# color 'red'
# }
#
# css.a :hover {
# text_decoration 'underline'
# }
#
# css.div(:id => 'menu') {
# background 'green'
# }
#
# css.div(:class => 'foo') {
# background 'red'
# }
#
# This will yield the following stylesheet:
#
# /* This is our stylesheet */
# body {
# background_color: #FAFAFA;
# font_size: small;
# font_family: Helvetica, Arial, sans_serif;
# color: #7F7F7F;
# }
#
# #navbar {
# width: 500px;
# }
#
# .navitem {
# color: red;
# }
#
# a:hover {
# text_decoration: underline;
# }
#
# div#menu {
# background: green;
# }
#
# div.foo {
# background: red;
# }
#
class CSS < BlankSlate
# Create a CSS builder.
#
# out:: Object receiving the markup.1 +out+ must respond to
# <tt><<</tt>.
# indent:: Number of spaces used for indentation (0 implies no
# indentation and no line breaks).
#
def initialize(indent=2)
@indent = indent
@target = []
@parts = []
@library = {}
end
def +(part)
_join_with_op! '+'
self
end
def >>(part)
_join_with_op! ''
self
end
def >(part)
_join_with_op! '>'
self
end
def |(part)
_join_with_op! ','
self
end
# Return the target of the builder
def target!
@target * ''
end
# Create a comment string in the output.
def comment!(comment_text)
@target << "/* #{comment_text} */\n"
end
def id!(arg, &block)
_start_container('#'+arg.to_s, nil, block_given?)
_css_block(block) if block
_unify_block
self
end
def class!(arg, &block)
_start_container('.'+arg.to_s, nil, block_given?)
_css_block(block) if block
_unify_block
self
end
def store!(sym, &block)
@library[sym] = block.to_proc
end
def group!(*args, &block)
args.each do |arg|
if arg.is_a?(Symbol)
instance_eval(&@library[arg])
else
instance_eval(&arg)
end
_text ', ' unless arg == args.last
end
if block
_css_block(block)
_unify_block
end
end
def method_missing(sym, *args, &block)
sym = "#{sym}:#{args.shift}" if args.first.kind_of?(Symbol)
if block
_start_container(sym, args.first)
_css_block(block)
_unify_block
elsif @in_block
_indent
_css_line(sym, *args)
_newline
return self
else
_start_container(sym, args.first, false)
_unify_block
end
self
end
# "Cargo culted" from Jim who also "cargo culted" it. See xmlbase.rb.
def nil?
false
end
private
def _unify_block
@target << @parts * ''
@parts = []
end
def _join_with_op!(op)
rhs, lhs = @target.pop, @target.pop
@target << "#{lhs} #{op} #{rhs}"
end
def _text(text)
@parts << text
end
def _css_block(block)
_newline
_nested_structures(block)
_end_container
_end_block
end
def _end_block
_newline
_newline
end
def _newline
_text "\n"
end
def _indent
_text ' ' * @indent
end
def _nested_structures(block)
@in_block = true
self.instance_eval(&block)
@in_block = false
end
def _start_container(sym, atts = {}, with_bracket = true)
selector = sym.to_s
selector << ".#{atts[:class]}" if atts && atts[:class]
selector << '#' + "#{atts[:id]}" if atts && atts[:id]
@parts << "#{selector}#{with_bracket ? ' {' : ''}"
end
def _end_container
@parts << "}"
end
def _css_line(sym, *args)
_text("#{sym.to_s.gsub('_','-')}: #{args * ' '};")
end
end
end
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