| Class | Builder::XmlBase |
| In: |
vendor/rails/activesupport/lib/active_support/vendor/builder-2.1.2/builder/xmlbase.rb
|
| Parent: | BlankSlate |
XmlBase is a base class for building XML builders. See Builder::XmlMarkup and Builder::XmlEvents for examples.
Create an XML markup builder.
| out: | Object receiving the markup. out must respond to <<. |
| indent: | Number of spaces used for indentation (0 implies no indentation and no line breaks). |
| initial: | Level of initial indentation. |
# File vendor/rails/activesupport/lib/active_support/vendor/builder-2.1.2/builder/xmlbase.rb, line 22
22: def initialize(indent=0, initial=0)
23: @indent = indent
24: @level = initial
25: end
Append text to the output target without escaping any markup. May be used within the markup brackets as:
builder.p { |x| x << "<br/>HI" } #=> <p><br/>HI</p>
This is useful when using non-builder enabled software that generates strings. Just insert the string directly into the builder without changing the inserted markup.
It is also useful for stacking builder objects. Builders only use << to append to the target, so by supporting this method/operation builders can use other builders as their targets.
# File vendor/rails/activesupport/lib/active_support/vendor/builder-2.1.2/builder/xmlbase.rb, line 97
97: def <<(text)
98: _text(text)
99: end
Create XML markup based on the name of the method. This method is never invoked directly, but is called for each markup method in the markup block.
# File vendor/rails/activesupport/lib/active_support/vendor/builder-2.1.2/builder/xmlbase.rb, line 37
37: def method_missing(sym, *args, &block)
38: text = nil
39: attrs = nil
40: sym = "#{sym}:#{args.shift}" if args.first.kind_of?(Symbol)
41: args.each do |arg|
42: case arg
43: when Hash
44: attrs ||= {}
45: attrs.merge!(arg)
46: else
47: text ||= ''
48: text << arg.to_s
49: end
50: end
51: if block
52: unless text.nil?
53: raise ArgumentError, "XmlMarkup cannot mix a text argument with a block"
54: end
55: _indent
56: _start_tag(sym, attrs)
57: _newline
58: _nested_structures(block)
59: _indent
60: _end_tag(sym)
61: _newline
62: elsif text.nil?
63: _indent
64: _start_tag(sym, attrs, true)
65: _newline
66: else
67: _indent
68: _start_tag(sym, attrs)
69: text! text
70: _end_tag(sym)
71: _newline
72: end
73: @target
74: end
For some reason, nil? is sent to the XmlMarkup object. If nil? is not defined and method_missing is invoked, some strange kind of recursion happens. Since nil? won‘t ever be an XML tag, it is pretty safe to define it here. (Note: this is an example of cargo cult programming, cf. fishbowl.pastiche.org/2004/10/13/cargo_cult_programming).
# File vendor/rails/activesupport/lib/active_support/vendor/builder-2.1.2/builder/xmlbase.rb, line 107
107: def nil?
108: false
109: end
Create a tag named sym. Other than the first argument which is the tag name, the arguments are the same as the tags implemented via method_missing.
# File vendor/rails/activesupport/lib/active_support/vendor/builder-2.1.2/builder/xmlbase.rb, line 30
30: def tag!(sym, *args, &block)
31: method_missing(sym.to_sym, *args, &block)
32: end
Append text to the output target. Escape any markup. May be used within the markup brackets as:
builder.p { |b| b.br; b.text! "HI" } #=> <p><br/>HI</p>
# File vendor/rails/activesupport/lib/active_support/vendor/builder-2.1.2/builder/xmlbase.rb, line 80
80: def text!(text)
81: _text(_escape(text))
82: end