Class: Puppet::Property Abstract

Inherits:
Parameter show all
Defined in:
lib/puppet/property.rb,
lib/puppet/type/zpool.rb,
lib/puppet/property/list.rb,
lib/puppet/property/keyvalue.rb,
lib/puppet/property/ordered_list.rb

Overview

This class is abstract.
Note:

Properties of Types are expressed using subclasses of this class. Such a class describes one named property of a particular Type (as opposed to describing a type of property in general). This limits the use of one (concrete) property class instance to occur only once for a given type’s inheritance chain. An instance of a Property class is the value holder of one instance of the resource type (e.g. the mode of a file resource instance). A Property class may server as the superclass _(parent)_ of another; e.g. a Size property that describes handling of measurements such as kb, mb, gb. If a type requires two different size measurements it requires one concrete class per such measure; e.g. MinSize (:parent => Size), and MaxSize (:parent => Size).

The Property class is the implementation of a resource’s attributes of property kind. A Property is a specialized Resource Type Parameter that has both an ‘is’ (current) state, and a ‘should’ (wanted state). However, even if this is conceptually true, the current is value is obtained by asking the associated provider for the value, and hence it is not actually part of a property’s state, and only available when a provider has been selected and can obtain the value (i.e. when running on an agent).

A Property (also in contrast to a parameter) is intended to describe a managed attribute of some system entity, such as the name or mode of a file.

The current value _(is)_ is read and written with the methods #retrieve and #set, and the wanted value _(should)_ is read and written with the methods #value and #value= which delegate to #should and #should=, i.e. when a property is used like any other parameter, it is the should value that is operated on.

All resource type properties in the puppet system are derived from this class.

The intention is that new parameters are created by using the DSL method Type.newproperty.

See Also:

Direct Known Subclasses

Boolean, Ensure, KeyValue, List, VDev, SELFileContext

Defined Under Namespace

Classes: Boolean, Ensure, KeyValue, List, MultiVDev, OrderedList, VDev

Constant Summary

Constants included from Util::Docs

Util::Docs::HEADER_LEVELS

Constants included from Util

Util::AbsolutePathPosix, Util::AbsolutePathWindows, Util::DEFAULT_POSIX_MODE, Util::DEFAULT_WINDOWS_MODE

Constants included from Util::POSIX

Util::POSIX::LOCALE_ENV_VARS, Util::POSIX::USER_ENV_VARS

Constants included from Util::SymbolicFileMode

Util::SymbolicFileMode::SetGIDBit, Util::SymbolicFileMode::SetUIDBit, Util::SymbolicFileMode::StickyBit, Util::SymbolicFileMode::SymbolicMode, Util::SymbolicFileMode::SymbolicSpecialToBit

Constants included from Util::Logging

Util::Logging::FILE_AND_LINE, Util::Logging::FILE_NO_LINE, Util::Logging::MM, Util::Logging::NO_FILE_LINE

Class Attribute Summary collapse

Instance Attribute Summary collapse

Attributes inherited from Parameter

#parent, #resource

Attributes included from Util::Docs

#doc, #nodoc

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Parameter

aliasvalue, defaultto, desc, doc, #file, format_value_for_display, #initialize, initvars, isnamevar, isnamevar?, #isnamevar?, isrequired, #line, #metaparam?, #munge, munge, newvalues, nodefault, #path, #pathbuilder, #provider, proxymethods, #remove, #required?, required?, #tags, #to_s, unmunge, #unmunge, #unsafe_munge, validate, #validate, #version

Methods included from Util::Docs

#desc, #dochook, #doctable, #markdown_definitionlist, #markdown_header, #nodoc?, #pad, scrub

Methods included from Util

absolute_path?, benchmark, chuser, clear_environment, default_env, deterministic_rand, deterministic_rand_int, exit_on_fail, get_env, get_environment, logmethods, merge_environment, path_to_uri, pretty_backtrace, replace_file, safe_posix_fork, set_env, symbolizehash, thinmark, uri_to_path, which, withenv, withumask

Methods included from Util::POSIX

#get_posix_field, #gid, #idfield, #methodbyid, #methodbyname, #search_posix_field, #uid

Methods included from Util::SymbolicFileMode

#normalize_symbolic_mode, #symbolic_mode_to_int, #valid_symbolic_mode?

Methods included from Util::MethodHelper

#requiredopts, #set_options, #symbolize_options

Methods included from Util::Logging

#clear_deprecation_warnings, #debug, #deprecation_warning, #format_exception, #get_deprecation_offender, #log_and_raise, #log_deprecations_to_file, #log_exception, #puppet_deprecation_warning, #send_log, setup_facter_logging!, #warn_once

Methods included from Util::Errors

#adderrorcontext, #devfail, #error_context, #exceptwrap, #fail

Constructor Details

This class inherits a constructor from Puppet::Parameter

Class Attribute Details

.array_matchingSymbol

Note:

The semantics of these modes are implemented by the method #insync?. That method is the default implementation and it has a backwards compatible behavior that imposes additional constraints on what constitutes a positive match. A derived property may override that method.

The ‘is` vs. `should` array matching mode; `:first`, or `:all`.

  • ‘:first` This is primarily used for single value properties. When matched against an array of values a match is true if the `is` value matches any of the values in the `should` array. When the `is` value is also an array, the matching is performed against the entire array as the `is` value.

  • ‘:all` : This is primarily used for multi-valued properties. When matched against an array of

    `should` values, the size of `is` and `should` must be the same, and all values in `is` must match
    a value in `should`.
    

Returns:

  • (Symbol)

    (:first) the mode in which matching is performed

See Also:



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# File 'lib/puppet/property.rb', line 90

def array_matching
  @array_matching ||= :first
end

.nameSymbol (readonly)

Returns The name of the property as given when the property was created.

Returns:

  • (Symbol)

    The name of the property as given when the property was created.



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# File 'lib/puppet/property.rb', line 66

def name
  @name
end

.unmanagedObject

TODO:

Figure out what this is used for. Can not find any logic in the puppet code base that reads or writes this attribute.

??? Probably Unused



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# File 'lib/puppet/property.rb', line 62

def unmanaged
  @unmanaged
end

Instance Attribute Details

#noopBoolean

TODO:

This logic is different than Parameter#noop in that the resource noop mode overrides the property’s mode - in parameter it is the other way around. Bug or feature?

Returns whether this property is in noop mode or not; if a difference between the is and should values should be acted on or not. The noop mode is a transitive setting. The mode is checked in this property, then in the _associated resource_ and finally in Puppet.

Returns:

  • (Boolean)

    whether this property is in noop mode or not.



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# File 'lib/puppet/property.rb', line 386

def noop
  # This is only here to make testing easier.
  if @resource.respond_to?(:noop?)
    @resource.noop?
  else
    if defined?(@noop)
      @noop
    else
      Puppet[:noop]
    end
  end
end

#shouldorigArray<Object>, ... (readonly)

Returns the original wanted value(s) _(should)_ unprocessed by munging/unmunging. The original values are set by #value= or #should=.

Returns:



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# File 'lib/puppet/property.rb', line 48

def shouldorig
  @shouldorig
end

Class Method Details

.method_added(sym) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Protects against override of the #safe_insync? method.

Raises:

  • (RuntimeError)

    if the added method is ‘:safe_insync?`



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# File 'lib/puppet/property.rb', line 266

def self.method_added(sym)
  raise "Puppet::Property#safe_insync? shouldn't be overridden; please override insync? instead" if sym == :safe_insync?
end

.newvalue(name, options = {}, &block) ⇒ Object

TODO:

Option :event original comment says “event should be returned…”, is “returned” the correct word to use?

Defines a new valid value for this property. A valid value is specified as a literal (typically a Symbol), but can also be specified with a Regexp.

Parameters:

  • name (Symbol, Regexp)

    a valid literal value, or a regexp that matches a value

  • options (Hash) (defaults to: {})

    a hash with options

Options Hash (options):

  • :event (Symbol)

    The event that should be emitted when this value is set.

  • :invalidate_refreshes (Symbol)

    Indicates a change on this property should invalidate and remove any scheduled refreshes (from notify or subscribe) targeted at the same resource. For example, if a change in this property takes into account any changes that a scheduled refresh would have performed, then the scheduled refresh would be deleted.

  • any (Object)

    Any other option is treated as a call to a setter having the given option name (e.g. ‘:required_features` calls `required_features=` with the option’s value as an argument).



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# File 'lib/puppet/property.rb', line 147

def self.newvalue(name, options = {}, &block)
  value = value_collection.newvalue(name, options, &block)

  unless value.method.nil?
    method = value.method.to_sym
    if value.block
      if instance_methods(false).include?(method)
        raise ArgumentError, "Attempt to redefine method #{method} with block"
      end
      define_method(method, &value.block)
    else
      # Let the method be an alias for calling the providers setter unless we already have this method
      alias_method(method, :call_provider) unless method_defined?(method)
    end
  end
  value
end

.value_name(name) ⇒ Symbol, Regexp

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Looks up a value’s name among valid values, to enable option lookup with result as a key.

Parameters:

  • name (Object)

    the parameter value to match against valid values (names).

Returns:

  • (Symbol, Regexp)

    a value matching predicate



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# File 'lib/puppet/property.rb', line 108

def self.value_name(name)
  if value = value_collection.match?(name)
    value.name
  end
end

.value_option(name, option) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

TODO:

Guessing on result of passing a non supported option (it performs send(option)).

Returns the value of the given option (set when a valid value with the given “name” was defined).

Parameters:

  • name (Symbol, Regexp)

    the valid value predicate as returned by value_name

  • option (Symbol)

    the name of the wanted option

Returns:

  • (Object)

    value of the option

Raises:

  • (NoMethodError)

    if the option is not supported



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# File 'lib/puppet/property.rb', line 122

def self.value_option(name, option)
  if value = value_collection.value(name)
    value.send(option)
  end
end

Instance Method Details

#call_provider(value) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Calls the provider setter method for this property with the given value as argument.

Returns:

  • (Object)

    what the provider returns when calling a setter for this property’s name

Raises:

  • (Puppet::Error)

    when the provider can not handle this property.

See Also:



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# File 'lib/puppet/property.rb', line 171

def call_provider(value)
  # We have no idea how to handle this unless our parent have a provider
  self.fail "#{self.class.name} cannot handle values of type #{value.inspect}" unless @resource.provider
  method = self.class.name.to_s + "="
  unless provider.respond_to? method
    self.fail "The #{provider.class.name} provider can not handle attribute #{self.class.name}"
  end
  provider.send(method, value)
end

#change_to_s(current_value, newvalue) ⇒ String

Note:

If called with equal values, this is reported as a change.

Formats a message for a property change from the given ‘current_value` to the given `newvalue`.

Returns:

  • (String)

    a message describing the property change.

Raises:



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# File 'lib/puppet/property.rb', line 186

def change_to_s(current_value, newvalue)
  begin
    if current_value == :absent
      return "defined '#{name}' as #{self.class.format_value_for_display should_to_s(newvalue)}"
    elsif newvalue == :absent or newvalue == [:absent]
      return "undefined '#{name}' from #{self.class.format_value_for_display is_to_s(current_value)}"
    else
      return "#{name} changed #{self.class.format_value_for_display is_to_s(current_value)} to #{self.class.format_value_for_display should_to_s(newvalue)}"
    end
  rescue Puppet::Error, Puppet::DevError
    raise
  rescue => detail
    message = "Could not convert change '#{name}' to string: #{detail}"
    Puppet.log_exception(detail, message)
    raise Puppet::DevError, message, detail.backtrace
  end
end

#eventPuppet::Transaction::Event

TODO:

What is the intent of this method? What is the meaning of the :source_description passed in the options to the created event?

Produces an event describing a change of this property. In addition to the event attributes set by the resource type, this method adds:

  • ‘:name` - the event_name

  • ‘:desired_value` - a.k.a should or _wanted value_

  • ‘:property` - reference to this property

  • ‘:source_description` - the path (?? See todo)

  • ‘:invalidate_refreshes` - if scheduled refreshes should be invalidated

Returns:

See Also:



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# File 'lib/puppet/property.rb', line 238

def event
  attrs = { :name => event_name, :desired_value => should, :property => self, :source_description => path }
  if should and value = self.class.value_collection.match?(should)
    attrs[:invalidate_refreshes] = true if value.invalidate_refreshes
  end
  resource.event attrs
end

#event_nameString

Produces the name of the event to use to describe a change of this property’s value. The produced event name is either the event name configured for this property, or a generic event based on the name of the property with suffix ‘_changed`, or if the property is `:ensure`, the name of the resource type and one of the suffixes `_created`, `_removed`, or `_changed`.

Returns:

  • (String)

    the name of the event that describes the change



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# File 'lib/puppet/property.rb', line 210

def event_name
  value = self.should

  event_name = self.class.value_option(value, :event) and return event_name

  name == :ensure or return (name.to_s + "_changed").to_sym

  return (resource.type.to_s + case value
  when :present; "_created"
  when :absent; "_removed"
  else
    "_changed"
  end).to_sym
end

#insync?(is) ⇒ Boolean

TODO:

The implementation should really do return is.zip(@should).all? {|a, b| property_matches?(a, b) } instead of using equality check and then check against an array with converted strings.

Note:

The array matching logic in this method contains backwards compatible logic that performs the comparison in ‘:all` mode by checking equality and equality of is against should converted to array of String, and that the lengths are equal, and in `:first` mode by checking if one of the should values is included in the is values. This means that the is value needs to be carefully arranged to match the should.

Checks if the current _(is)_ value is in sync with the wanted _(should)_ value. The check if the two values are in sync is controlled by the result of #match_all? which specifies a match of ‘:first` or `:all`). The matching of the is value against the entire should value or each of the should values (as controlled by #match_all? is performed by #property_matches?.

A derived property typically only needs to override the #property_matches? method, but may also override this method if there is a need to have more control over the array matching logic.

Parameters:

  • is (Object)

    The current _(is)_ value to check if it is in sync with the wanted _(should)_ value(s)

Returns:

  • (Boolean)

    whether the values are in sync or not.

Raises:



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# File 'lib/puppet/property.rb', line 290

def insync?(is)
  self.devfail "#{self.class.name}'s should is not array" unless @should.is_a?(Array)

  # an empty array is analogous to no should values
  return true if @should.empty?

  # Look for a matching value, either for all the @should values, or any of
  # them, depending on the configuration of this property.
  if match_all? then
    # Emulate Array#== using our own comparison function.
    # A non-array was not equal to an array, which @should always is.
    return false unless is.is_a? Array

    # If they were different lengths, they are not equal.
    return false unless is.length == @should.length

    # Finally, are all the elements equal?  In order to preserve the
    # behaviour of previous 2.7.x releases, we need to impose some fun rules
    # on "equality" here.
    #
    # Specifically, we need to implement *this* comparison: the two arrays
    # are identical if the is values are == the should values, or if the is
    # values are == the should values, stringified.
    #
    # This does mean that property equality is not commutative, and will not
    # work unless the `is` value is carefully arranged to match the should.
    return (is == @should or is == @should.map(&:to_s))

    # When we stop being idiots about this, and actually have meaningful
    # semantics, this version is the thing we actually want to do.
    #
    # return is.zip(@should).all? {|a, b| property_matches?(a, b) }
  else
    return @should.any? {|want| property_matches?(is, want) }
  end
end

#is_to_s(currentvalue) ⇒ String

Produces a pretty printing string for the given value. This default implementation simply returns the given argument. A derived implementation may perform property specific pretty printing when the is and should values are not already in suitable form.

Returns:

  • (String)

    a pretty printing string



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# File 'lib/puppet/property.rb', line 349

def is_to_s(currentvalue)
  currentvalue
end

#log(msg) ⇒ void

This method returns an undefined value.

Emits a log message at the log level specified for the associated resource. The log entry is associated with this property.

Parameters:

  • msg (String)

    the message to log



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# File 'lib/puppet/property.rb', line 358

def log(msg)
  Puppet::Util::Log.create(
    :level   => resource[:loglevel],
    :message => msg,
    :source  => self
  )
end

#match_all?Boolean

Returns whether the array_matching mode is set to ‘:all` or not.

Returns:



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# File 'lib/puppet/property.rb', line 367

def match_all?
  self.class.array_matching == :all
end

#nameSymbol

Note:

A property class (just like a parameter class) describes one specific property and can only be used once within one type’s inheritance chain.

Returns the name of the property as stated when the property was created.

Returns:

  • (Symbol)

    the name of the property as stated when the property was created.



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# File 'lib/puppet/property.rb', line 374

def name
  self.class.name
end

#property_matches?(current, desired) ⇒ Boolean

Checks if the given current and desired values are equal. This default implementation performs this check in a backwards compatible way where the equality of the two values is checked, and then the equality of current with desired converted to a string.

A derived implementation may override this method to perform a property specific equality check.

The intent of this method is to provide an equality check suitable for checking if the property value is in sync or not. It is typically called from #insync?.

Returns:



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# File 'lib/puppet/property.rb', line 337

def property_matches?(current, desired)
  # This preserves the older Puppet behaviour of doing raw and string
  # equality comparisons for all equality.  I am not clear this is globally
  # desirable, but at least it is not a breaking change. --daniel 2011-11-11
  current == desired or current == desired.to_s
end

#retrieveObject

Retrieves the current value _(is)_ of this property from the provider. This implementation performs this operation by calling a provider method with the same name as this property (i.e. if the property name is ‘gid’, a call to the ‘provider.gid’ is expected to return the current value.

Returns:

  • (Object)

    what the provider returns as the current value of the property



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# File 'lib/puppet/property.rb', line 405

def retrieve
  provider.send(self.class.name)
end

#safe_insync?(is) ⇒ Boolean

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Note:

If the wanted value _(should)_ is not defined or is set to a non-true value then this is a state that can not be fixed and the property is reported to be in sync.

Note:

Do not override this method.

Determines whether the property is in-sync or not in a way that is protected against missing value.

Returns:

  • (Boolean)

    the protected result of ‘true` or the result of calling #insync?.



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# File 'lib/puppet/property.rb', line 254

def safe_insync?(is)
  # If there is no @should value, consider the property to be in sync.
  return true unless @should

  # Otherwise delegate to the (possibly derived) insync? method.
  insync?(is)
end

#set(value) ⇒ Object

Sets the current _(is)_ value of this property. The name associated with the value is first obtained by calling value_name. A dynamically created setter method associated with this name is called if it exists, otherwise the value is set using using the provider’s setter method for this property by calling (#call_provider).

Parameters:

  • value (Object)

    the value to set

Returns:

Raises:

  • (Puppet::Error)

    if there were problems setting the value using the setter method or when the provider setter should be used but there is no provider in the associated resource_

  • (Puppet::ResourceError)

    if there was a problem setting the value and it was not raised as a Puppet::Error. The original exception is wrapped and logged.



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# File 'lib/puppet/property.rb', line 422

def set(value)
  # Set a name for looking up associated options like the event.
  name = self.class.value_name(value)
  if method = self.class.value_option(name, :method) and self.respond_to?(method)
    begin
      self.send(method)
    rescue Puppet::Error
      raise
    rescue => detail
      error = Puppet::ResourceError.new("Could not set '#{value}' on #{self.class.name}: #{detail}", @resource.line, @resource.file, detail)
      error.set_backtrace detail.backtrace
      Puppet.log_exception(detail, error.message)
      raise error
    end
  elsif block = self.class.value_option(name, :block)
    # FIXME It'd be better here to define a method, so that
    # the blocks could return values.
    self.instance_eval(&block)
  else
    call_provider(value)
  end
end

#shouldArray<Object>, ...

Note:

This method will potentially return different values than the original values as they are converted via munging/unmunging. If the original values are wanted, call #shouldorig.

Returns the wanted _(should)_ value of this property. If the _array matching mode_ #match_all? is true, an array of the wanted values in unmunged format is returned, else the first value in the array of wanted values in unmunged format is returned.

Returns:

Raises:

See Also:



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# File 'lib/puppet/property.rb', line 458

def should
  return nil unless defined?(@should)

  self.devfail "should for #{self.class.name} on #{resource.name} is not an array" unless @should.is_a?(Array)

  if match_all?
    return @should.collect { |val| self.unmunge(val) }
  else
    return self.unmunge(@should[0])
  end
end

#should=(values) ⇒ Object

Sets the wanted _(should)_ value of this property. If the given value is not already an Array, it will be wrapped in one before being set. This method also sets the cached original should values returned by #shouldorig.

Parameters:

Raises:



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# File 'lib/puppet/property.rb', line 478

def should=(values)
  values = [values] unless values.is_a?(Array)

  @shouldorig = values

  values.each { |val| validate(val) }
  @should = values.collect { |val| self.munge(val) }
end

#should_to_s(newvalue) ⇒ String

Formats the given newvalue (following should type conventions) for inclusion in a string describing a change.

Returns:

  • (String)

    Returns the given newvalue in string form with space separated entries if it is an array.

See Also:



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# File 'lib/puppet/property.rb', line 491

def should_to_s(newvalue)
  [newvalue].flatten.join(" ")
end

#syncObject

TODO:

The implementation of this method is somewhat inefficient as it computes the should array twice.

Synchronizes the current value _(is)_ and the wanted value _(should)_ by calling #set.

Raises:



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# File 'lib/puppet/property.rb', line 499

def sync
  devfail "Got a nil value for should" unless should
  set(should)
end

#unsafe_validate(value) ⇒ void

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

This method returns an undefined value.

Asserts that the given value is valid. If the developer uses a ‘validate’ hook, this method will get overridden.

Raises:

  • (Exception)

    if the value is invalid, or value can not be handled.



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# File 'lib/puppet/property.rb', line 510

def unsafe_validate(value)
  super
  validate_features_per_value(value)
end

#validate_features_per_value(value) ⇒ void

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

This method returns an undefined value.

Asserts that all required provider features are present for the given property value.

Raises:

  • (ArgumentError)

    if a required feature is not present



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# File 'lib/puppet/property.rb', line 520

def validate_features_per_value(value)
  if features = self.class.value_option(self.class.value_name(value), :required_features)
    features = Array(features)
    needed_features = features.collect { |f| f.to_s }.join(", ")
    raise ArgumentError, "Provider must have features '#{needed_features}' to set '#{self.class.name}' to '#{value}'" unless provider.satisfies?(features)
  end
end

#valueObject?

Returns the wanted _(should)_ value of this property.

Returns:

  • (Object, nil)

    Returns the wanted _(should)_ value of this property.



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# File 'lib/puppet/property.rb', line 529

def value
  self.should
end

#value=(values) ⇒ Object

Sets the wanted _(should)_ value of this property. If the given value is not already an Array, it will be wrapped in one before being set. This method also sets the cached original should values returned by #shouldorig.

Parameters:

Raises:



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# File 'lib/puppet/property.rb', line 534

def value=(values)
  self.should = values
end