tag_helper.coffee

# Copyright (C) 2012 Mark Huetsch
#
# Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

require 'cream'

class TagHelper

  HTML_ESCAPE = { '&': '&amp;', '>': '&gt;', '<': '&lt;', '"': '&quot;' }
  JSON_ESCAPE = { '&': '\u0026', '>': '\u003E', '<': '\u003C' }
  BOOLEAN_ATTRIBUTES = [
    'disabled', 'readonly', 'multiple', 'checked', 'autobuffer', 'autoplay', 'controls', 'loop', 'selected', 'hidden', 'scoped',
    'async', 'defer', 'reversed', 'ismap', 'seemless', 'muted', 'required', 'autofocus', 'novalidate', 'formnovalidate', 'open',
    'pubdate'
  ]

  # ==== Example:
  # puts html_escape("is a > 0 & a < 10?")
  # # => is a &gt; 0 &amp; a &lt; 10?
  html_escape: (s) ->
    unless s instanceof String
      s = String s
    unless s.is_html_safe?
      s.replace(/&/g, "&amp;").replace(/\"/g, "&quot;").replace(/>/g, "&gt;").replace(/</g, "&lt;").html_safe()
    else
      s

  tag: (name, options = null, open = false, escape = true) ->
    tag_options = ''
    if options
      tag_options = @tag_options(options, escape)
    "<#{name}#{tag_options}#{if open then '>' else ' />'}".html_safe()

  content_tag: (name, content_or_options_with_block = null, options = null, escape = true) ->
    @content_tag_string(name, content_or_options_with_block, options, escape)

  content_tag_string: (name, content, options, escape = true) ->
    tag_options = if options then @tag_options(options, escape) else ''
    "<#{name}#{tag_options}>#{if escape then @html_escape(content) else content}</#{name}>".html_safe()

  tag_options: (options, escape = true) ->
    keys = (k for k, v of options)
    unless keys.length is 0
      attrs = []
      for key, value of options
        if key is 'data' and typeof value is 'object'
          for k, v of value
            unless typeof v is 'string'
              v = JSON.stringify v
            if escape
              v = @html_escape v
            attrs.push "data-#{k.dasherize()}=\"#{v}\""
        else if key in BOOLEAN_ATTRIBUTES
          if value
            attrs.push "#{key}=\"#{key}\""
        else if (value isnt null and value isnt undefined)
          final_value = value
          if value instanceof Array
            final_value = value.join(" ")
          if escape
            final_value = @html_escape(final_value)
          attrs.push "#{key}=\"#{final_value}\""
      unless attrs.length is 0
        " #{attrs.sort().join(' ')}".html_safe()

helper = new TagHelper()

#class SafeBuffer extends String
  # not really sure why we need to override these values...
#  constructor: (__value__) ->
#    @dirty = false
#    @length = (@__value__ = __value__ or "").length
#    super __value__
#  toString: -> @__value__
#  valueOf: -> @__value__
#
#  is_dirty: ->
#    @dirty
#
#  is_html_safe: ->
#    not @dirty
#
#  concat: (other) ->
#    if @is_dirty() or other.is_html_safe()
#      super(other)
#    else
#      super(helper.html_escape(other))
#
 # XXX we can't overload operators in javascript
 #+: ->
 #  'a' + @__value__
#String::html_safe = -> new SafeBuffer(this.valueOf())

exports.html_escape = helper.html_escape
exports.tag = helper.tag
exports.content_tag = helper.content_tag_string
exports.tag_options = helper.tag_options