Class: Attributor::Attribute

Inherits:
Object
  • Object
show all
Defined in:
lib/attributor/attribute.rb

Overview

It is the abstract base class to hold an attribute, both a leaf and a container (hash/Array…) TODO: should this be a mixin since it is an abstract class?

Constant Summary collapse

TOP_LEVEL_OPTIONS = 
[ :description, :values, :default, :example, :required, :required_if, :custom_data ]
INTERNAL_OPTIONS =

Options we don’t want to expose when describing attributes

[:dsl_compiler,:dsl_compiler_options]

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(type, options = {}, &block) ⇒ Attribute

@options: metadata about the attribute @block: code definition for struct attributes (nil for predefined types or leaf/simple types)



26
27
28
29
30
31
32
33
34
35
 
# File 'lib/attributor/attribute.rb', line 26

def initialize(type, options={}, &block)
  @type = Attributor.resolve_type(type, options, block)

  @options = options
  if @type.respond_to?(:options)
    @options = @type.options.merge(@options)
  end

  check_options!
end

Instance Attribute Details

#options ⇒ Object (readonly)

Returns the value of attribute options.



22
23
24
 
# File 'lib/attributor/attribute.rb', line 22

def options
  @options
end

#type ⇒ Object (readonly)

Returns the value of attribute type.



22
23
24
 
# File 'lib/attributor/attribute.rb', line 22

def type
  @type
end

Instance Method Details

#==(attribute) ⇒ Object

Raises:

  • (ArgumentError) 


37
38
39
40
41
42
 
# File 'lib/attributor/attribute.rb', line 37

def ==(attribute)
  raise ArgumentError, "can not compare Attribute with #{attribute.class.name}" unless attribute.kind_of?(Attribute)

  self.type == attribute.type &&
    self.options == attribute.options
end

#attributes ⇒ Object 



184
185
186
187
188
189
190
 
# File 'lib/attributor/attribute.rb', line 184

def attributes
  if (@type_has_attributes ||= type.respond_to?(:attributes))
    type.attributes
  else
    nil
  end
end

#check_option!(name, definition) ⇒ Object

TODO: override in type subclass



283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
 
# File 'lib/attributor/attribute.rb', line 283

def check_option!(name, definition)
  case name
  when :values
    raise AttributorException.new("Allowed set of values requires an array. Got (#{definition})") unless definition.is_a? ::Array
  when :default
    raise AttributorException.new("Default value doesn't have the correct attribute type. Got (#{definition.inspect})") unless self.type.valid_type?(definition) || definition.kind_of?(Proc)
    self.options[:default] = self.load(definition) unless definition.kind_of?(Proc)
  when :description
    raise AttributorException.new("Description value must be a string. Got (#{definition})") unless definition.is_a? ::String
  when :required
    raise AttributorException.new("Required must be a boolean") unless !!definition == definition # Boolean check
    raise AttributorException.new("Required cannot be enabled in combination with :default") if definition == true && options.has_key?(:default)
  when :required_if
    raise AttributorException.new("Required_if must be a String, a Hash definition or a Proc") unless definition.is_a?(::String) || definition.is_a?(::Hash) || definition.is_a?(::Proc)
    raise AttributorException.new("Required_if cannot be specified together with :required") if self.options[:required]
  when :example
    unless definition.is_a?(::Regexp) || definition.is_a?(::String) || definition.is_a?(::Array) || definition.is_a?(::Proc) || definition.nil? || self.type.valid_type?(definition)
      raise AttributorException.new("Invalid example type (got: #{definition.class.name}). It must always match the type of the attribute (except if passing Regex that is allowed for some types)")
    end
  when :custom_data
    raise AttributorException.new("custom_data must be a Hash. Got (#{definition})") unless definition.is_a?(::Hash)
  else
    return :unknown # unknown option
  end

  :ok # passes
end

#check_options! ⇒ Object 



269
270
271
272
273
274
275
276
277
278
279
 
# File 'lib/attributor/attribute.rb', line 269

def check_options!
  self.options.each do |option_name, option_value|
    if self.check_option!(option_name, option_value) == :unknown
      if self.type.check_option!(option_name, option_value) == :unknown
        raise AttributorException.new("unsupported option: #{option_name} with value: #{option_value.inspect} for attribute: #{self.inspect}")
      end
    end
  end

  true
end

#describe(shallow = true, example: nil) ⇒ Object 



102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
 
# File 'lib/attributor/attribute.rb', line 102

def describe(shallow=true, example: nil)
  description = { }
  # Clone the common options
  TOP_LEVEL_OPTIONS.each do |option_name|
    description[option_name] = self.options[option_name] if self.options.has_key? option_name
  end

  # Make sure this option definition is not mistaken for the real generated example
  if ( ex_def = description.delete(:example) )
    description[:example_definition] = ex_def
  end

  special_options = self.options.keys - TOP_LEVEL_OPTIONS - INTERNAL_OPTIONS
  description[:options] = {} unless special_options.empty?
  special_options.each do |opt_name|
    description[:options][opt_name] = self.options[opt_name]
  end
  # Change the reference option to the actual class name.
  if ( reference = self.options[:reference] )
    description[:options][:reference] = reference.name
  end

  description[:type] = self.type.describe(shallow, example: example )
  # Move over any example from the type, into the attribute itself
  if ( ex = description[:type].delete(:example) )
    description[:example] = self.dump(ex)
  end

  description
end

#dump(value, **opts) ⇒ Object 



82
83
84
 
# File 'lib/attributor/attribute.rb', line 82

def dump(value, **opts)
  type.dump(value, **opts)
end

#example(context = nil, parent: nil, values: {}) ⇒ Object

Raises:

  • (ArgumentError) 


155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
 
# File 'lib/attributor/attribute.rb', line 155

def example(context=nil, parent: nil, values:{})
  raise ArgumentError, "attribute example cannot take a context of type String" if (context.is_a? ::String )
  if context
    ctx = Attributor.humanize_context(context)
    seed, _ = Digest::SHA1.digest(ctx).unpack("QQ")
    Random.srand(seed)
  else
    context = Attributor::DEFAULT_ROOT_CONTEXT
  end

  if self.options.has_key? :example
    loaded = example_from_options(parent, context)
    errors = self.validate(loaded, context)
    raise AttributorException, "Error generating example for #{Attributor.humanize_context(context)}. Errors: #{errors.inspect}" if errors.any?
    loaded
  else
    if (option_values = self.options[:values])
      option_values.pick
    else
      if type.respond_to?(:attributes)
        self.type.example(context, values)
      else
        self.type.example(context, options: self.options)
      end
    end
  end
end

#example_from_options(parent, context) ⇒ Object 



134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
 
# File 'lib/attributor/attribute.rb', line 134

def example_from_options(parent, context)
  val = self.options[:example]
  generated = case val
  when ::Regexp
    val.gen
  when ::Proc
    if val.arity == 2
      val.call(parent, context)
    elsif val.arity == 1
      val.call(parent)
    else
      val.call
    end
  when nil
    nil
  else
    val
  end
  self.load( generated, context )
end

#load(value, context = Attributor::DEFAULT_ROOT_CONTEXT, **options) ⇒ Object 



53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
 
# File 'lib/attributor/attribute.rb', line 53

def load(value, context=Attributor::DEFAULT_ROOT_CONTEXT,  **options)
  value = type.load(value,context,**options)

  if value.nil? && self.options.has_key?(:default)
    defined_val = self.options[:default]
    val = case defined_val
    when ::Proc
      fake_parent = FakeParent.new
      # TODO: we can only support "context" as a parameter to the proc for now, since we don't have the parent...
      if defined_val.arity == 2
        defined_val.call(fake_parent, context)
      elsif defined_val.arity == 1
        defined_val.call(fake_parent)
      else
        defined_val.call
      end
    else
      defined_val
    end
    value = val #Need to load?
  end

  value
rescue AttributorException, NameError
  raise
rescue => e
  raise Attributor::LoadError, "Error loading attribute #{Attributor.humanize_context(context)} of type #{type.name} from value #{Attributor.errorize_value(value)}\n#{e.message}"
end

#parse(value, context = Attributor::DEFAULT_ROOT_CONTEXT) ⇒ Object 



45
46
47
48
49
50
 
# File 'lib/attributor/attribute.rb', line 45

def parse(value, context=Attributor::DEFAULT_ROOT_CONTEXT)
  object = self.load(value,context)

  errors = self.validate(object,context)
  [ object, errors ]
end

#validate(object, context = Attributor::DEFAULT_ROOT_CONTEXT) ⇒ Object

Validates stuff and checks dependencies



194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
 
# File 'lib/attributor/attribute.rb', line 194

def validate(object, context=Attributor::DEFAULT_ROOT_CONTEXT )
  raise "INVALID CONTEXT!! #{context}" unless context
  # Validate any requirements, absolute or conditional, and return.

  if object.nil? # == Attributor::UNSET
    # With no value, we can only validate whether that is acceptable or not and return.
    # Beyond that, no further validation should be done.
    return self.validate_missing_value(context)
  end

  # TODO: support validation for other types of conditional dependencies based on values of other attributes

  errors = self.validate_type(object,context)

  # End validation if we don't even have the proper type to begin with
  return errors if errors.any?

  if self.options[:values] && !self.options[:values].include?(object)
    errors << "Attribute #{Attributor.humanize_context(context)}: #{Attributor.errorize_value(object)} is not within the allowed values=#{self.options[:values].inspect} "
  end

  errors + self.type.validate(object,context,self)
end

#validate_missing_value(context) ⇒ Object 



219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
 
# File 'lib/attributor/attribute.rb', line 219

def validate_missing_value(context)
  raise "INVALID CONTEXT!!! (got: #{context.inspect})" unless context.is_a? Enumerable

  # Missing attribute was required if :required option was set
  return ["Attribute #{Attributor.humanize_context(context)} is required"] if self.options[:required]

  # Missing attribute was not required if :required_if (and :required)
  # option was NOT set
  requirement = self.options[:required_if]
  return [] unless requirement

  case requirement
  when ::String
    key_path = requirement
    predicate = nil
  when ::Hash
    # TODO: support multiple dependencies?
    key_path = requirement.keys.first
    predicate = requirement.values.first
  else
    # should never get here if the option validation worked...
    raise AttributorException.new("unknown type of dependency: #{requirement.inspect} for #{Attributor.humanize_context(context)}")
  end

  # chop off the last part
  requirement_context = context[0..-2]
  requirement_context_string = requirement_context.join(Attributor::SEPARATOR)

  # FIXME: we're having to reconstruct a string context just to use the resolver...smell.
  if AttributeResolver.current.check(requirement_context_string, key_path, predicate)
    message = "Attribute #{Attributor.humanize_context(context)} is required when #{key_path} "

    # give a hint about what the full path for a relative key_path would be
    unless key_path[0..0] == Attributor::AttributeResolver::ROOT_PREFIX
      message << "(for #{Attributor.humanize_context(requirement_context)}) "
    end

    if predicate
      message << "matches #{predicate.inspect}."
    else
      message << "is present."
    end

    [message]
  else
    []
  end
end

#validate_type(value, context) ⇒ Object 



87
88
89
90
91
92
93
94
95
96
 
# File 'lib/attributor/attribute.rb', line 87

def validate_type(value, context)
  # delegate check to type subclass if it exists
  unless self.type.valid_type?(value)
    msg = "Attribute #{Attributor.humanize_context(context)} received value: "
    msg += "#{Attributor.errorize_value(value)} is of the wrong type "
    msg += "(got: #{value.class.name}, expected: #{self.type.name})"
    return [msg]
  end
  []
end