Class: Bosh::Template::EvaluationContext

Inherits:
Object
  • Object
show all
Includes:
PropertyHelper
Defined in:
lib/bosh/template/evaluation_context.rb

Overview

Helper class to evaluate templates. Used by Director, CLI and Agent.

Defined Under Namespace

Classes: ActiveElseBlock, InactiveElseBlock

Instance Attribute Summary collapse

Instance Method Summary collapse

Methods included from PropertyHelper

#copy_property, #lookup_property

Constructor Details

#initialize(spec) ⇒ EvaluationContext 



29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
 
# File 'lib/bosh/template/evaluation_context.rb', line 29

def initialize(spec)
  unless spec.is_a?(Hash)
    raise EvaluationFailed,
          'Invalid spec provided for template evaluation context, ' +
              "Hash expected, #{spec.class} given"
  end

  if spec['job'].is_a?(Hash)
    @name = spec['job']['name']
  else
    @name = nil
  end

  @index = spec['index']
  @spec = openstruct(spec)
  @raw_properties = spec['properties'] || {}
  @properties = openstruct(@raw_properties)

  @links = spec['links'] || {}
end

Instance Attribute Details

#index ⇒ Integer (readonly) 



17
18
19
 
# File 'lib/bosh/template/evaluation_context.rb', line 17

def index
  @index
end

#name ⇒ String (readonly) 



14
15
16
 
# File 'lib/bosh/template/evaluation_context.rb', line 14

def name
  @name
end

#properties ⇒ Hash (readonly) 



20
21
22
 
# File 'lib/bosh/template/evaluation_context.rb', line 20

def properties
  @properties
end

#raw_properties ⇒ Hash (readonly) 



23
24
25
 
# File 'lib/bosh/template/evaluation_context.rb', line 23

def raw_properties
  @raw_properties
end

#spec ⇒ Hash (readonly) 



26
27
28
 
# File 'lib/bosh/template/evaluation_context.rb', line 26

def spec
  @spec
end

Instance Method Details

#get_binding ⇒ Binding 



51
52
53
 
# File 'lib/bosh/template/evaluation_context.rb', line 51

def get_binding
  binding.taint
end

#if_p(*names) {|Object| ... } ⇒ Object

Run a block of code if all given properties are defined

Yields:

  • (Object) —

    property values



104
105
106
107
108
109
110
111
112
113
 
# File 'lib/bosh/template/evaluation_context.rb', line 104

def if_p(*names)
  values = names.map do |name|
    value = lookup_property(@raw_properties, name)
    return ActiveElseBlock.new(self) if value.nil?
    value
  end

  yield *values
  InactiveElseBlock.new
end

#link(name) ⇒ Object

Raises:



94
95
96
97
98
99
 
# File 'lib/bosh/template/evaluation_context.rb', line 94

def link(name)
  result = lookup_property(@links, name)
  return result unless result.nil?

  raise UnknownLink.new(name)
end

#openstruct(object) ⇒ Object 



118
119
120
121
122
123
124
125
126
127
128
 
# File 'lib/bosh/template/evaluation_context.rb', line 118

def openstruct(object)
  case object
    when Hash
      mapped = object.inject({}) { |h, (k, v)| h[k] = openstruct(v); h }
      OpenStruct.new(mapped)
    when Array
      object.map { |item| openstruct(item) }
    else
      object
  end
end

#p(name, default_value) ⇒ Object #p(names, default_value) ⇒ Object #p(names) ⇒ Object #p(name) ⇒ Object

Property lookup helper

Overloads:

  • #p(name, default_value) ⇒ Object

    Returns property value or default value if property not set

  • #p(names, default_value) ⇒ Object

    Returns first property from the list that is set or default value if none of them are set

  • #p(names) ⇒ Object

    Looks up first property from the list that is set, raises an error if none of them are set.

    Raises:

    • (Bosh::Common::UnknownProperty)
  • #p(name) ⇒ Object

    Looks up property and raises an error if it’s not set

    Raises:

    • (Bosh::Common::UnknownProperty)

Raises:



82
83
84
85
86
87
88
89
90
91
92
 
# File 'lib/bosh/template/evaluation_context.rb', line 82

def p(*args)
  names = Array(args[0])

  names.each do |name|
    result = lookup_property(@raw_properties, name)
    return result unless result.nil?
  end

  return args[1] if args.length == 2
  raise UnknownProperty.new(names)
end