Class: XmlLens

Inherits:
Object
  • Object
show all
Defined in:
lib/puppet/provider/xmlfile/lens.rb

Overview

XMLLens wraps around rexml/document and XPath to provide augeas esque-manipulation of an xml file.

Instance Method Summary collapse

Constructor Details

#initialize(xml, changes = nil, conditions = nil) ⇒ XmlLens

Initialized with the file(preloaded), any changes and any conditions

Raises:

  • (ArgumentError) 


7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
 
# File 'lib/puppet/provider/xmlfile/lens.rb', line 7

def initialize(xml, changes = nil, conditions = nil)
  raise ArgumentError unless xml.is_a? REXML::Document
  @xml = xml
  @operations = Array.new
  @validations = Array.new
  
  # Initialize our ops and validations
  # these get batched and executed en-masse
  unless changes.nil?
    if changes.is_a? Array
      changes.each { |change| parser(change) }
    elsif changes.is_a? String
      parser(changes)
    else
      raise ArgumentError
    end
  end
  
  unless conditions.nil?
    if conditions.is_a? Array
      conditions.each { |condition| parser(condition) }
    elsif conditions.is_a? String
      parser(conditions)
    end
  end
end

Instance Method Details

#clear(path) ⇒ Object

Clears an element



54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
 
# File 'lib/puppet/provider/xmlfile/lens.rb', line 54

def clear(path)
  puts "clear #{path.inspect}"
  if path.is_a? Array
    path.each do |p|
      p.elements.each do |child|
        p.elements.delete(child)
      end
      p.text = nil
      p.attributes.keys.each do |key|
        p.attributes.delete(key)
      end
    end
  elsif path.is_a? REXML::Element
    path.elements.each do |child|
      path.elements.delete(child)
    end
    path.text = nil
    path.attributes.keys.each do |key|
      path.attributes.delete(key)
    end
  else
    raise ArgumentError
  end
end

#evaluate ⇒ Object

Evaluates. Calls the procs that have been loaded.



40
41
42
43
44
45
46
47
48
49
50
51
 
# File 'lib/puppet/provider/xmlfile/lens.rb', line 40

def evaluate
  # First up validations
  @validations.each do |validate|
    next if validate.call
    return @xml
  end
  # Those passed, so next up is actual operations
  @operations.each do |operation|
    operation.call
  end
  return @xml
end

#get(match, expr, value, attr) ⇒ Object

Checks if a match has a certain value(attribute or text)



80
81
82
83
84
85
86
87
88
89
90
91
 
# File 'lib/puppet/provider/xmlfile/lens.rb', line 80

def get(match, expr, value, attr)
  retval = false
  match.each do |m|
    if attr and attr.length > 0
      retval = evaluate_expression(m.attributes[attr], expr, value)
    else
      retval = evaluate_expression(m.text, expr, value)
    end
    break if retval
  end
  return retval
end

#match(match, xml = @xml) ⇒ Object

Wrap around XPath.match



35
36
37
 
# File 'lib/puppet/provider/xmlfile/lens.rb', line 35

def match(match, xml = @xml)
  REXML::XPath.match(xml, match)
end

#rm(path) ⇒ Object

Deletes a node



94
95
96
97
98
99
100
101
102
103
104
 
# File 'lib/puppet/provider/xmlfile/lens.rb', line 94

def rm(path)
  if path.is_a? Array
    path.each do |p|
      p.parent.elements.delete(p) if p.parent
    end
  elsif path.is_a? REXML::Element
    path.parent.elements.delete(p) if path.parent
  else
    raise ArgumentError
  end
end

#set(element, value, attribute, path) ⇒ Object

Sets a node or node attribute to a value. Creates it if it doesn’t exist



107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
 
# File 'lib/puppet/provider/xmlfile/lens.rb', line 107

def set(element, value, attribute, path)
  unless element.nil?
    set_element = element.first
  else
    built_path = build_path(path.scan(/\/([^\[\/]*)(\[[^\]\[]*\])?+/))
    if built_path[:exists]
      set_element = built_path[:final_path].first
    else
      set_element = built_path[:final_path].first
      built_path[:remainder].each do |add|
        set_element = set_element.elements.add(add)
      end
    end
  end
  if attribute
    set_element.attributes[attribute] = value
  else
    set_element.text = value
  end
end

#sort(element, attr, type) ⇒ Object

Type is ignored for now as I didn’t really have a use case for it.



129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
 
# File 'lib/puppet/provider/xmlfile/lens.rb', line 129

def sort(element, attr, type)
  if element.is_a?(Array)
    element.each do |elem|
      case attr
      when "text"
        sorted = elem.elements.sort { |e1, e2| e1.text <=> e2.text }
      when nil
        sorted = elem.elements.sort { |e1, e2| e1.name <=> e2.name }
      else
        sorted = elem.elements.sort { |e1, e2| e1.attributes[attr] <=> e2.attributes[attr] }
      end
      elem.elements.each { |a| elem.elements.delete(a) }
      sorted.each { |a| elem.add_element(a) }
    end
  elsif element.is_a? REXML::Element
    case attr
    when "text"
      sorted = elem.elements.sort { |e1, e2| e1.text <=> e2.text }
    when nil
      sorted = elem.elements.sort { |e1, e2| e1.name <=> e2.name }
    else
      sorted = elem.elements.sort { |e1, e2| e1.attributes[attr] <=> e2.attributes[attr] }
    end
    element.elements.each { |a| element.elements.delete(a) }
    sorted.each { |a| element.add_element(a) }
  end
end