Mail::SPF::Mod(3) User Contributed Perl Documentation Mail::SPF::Mod(3)NAME
Mail::SPF::Mod - SPF record modifier base class
DESCRIPTION
An object of class Mail::SPF::Mod represents a modifier within an SPF
record. Mail::SPF::Mod cannot be instantiated directly. Create an
instance of a concrete sub-class instead.
Constructors
The following constructors are provided:
new(%options): returns Mail::SPF::Mod
Abstract. Creates a new SPF record modifier object.
%options is a list of key/value pairs representing any of the
following options:
text
A string denoting the unparsed text of the modifier.
name
A string denoting the name of the modifier. Required if a
generic Mail::SPF::Mod object (as opposed to a specific sub-
class) is being constructed.
domain_spec
Either a plain string or a Mail::SPF::MacroString object
denoting an optional "domain-spec" parameter of the mechanism.
new_from_string($text, %options): returns Mail::SPF::Mod; throws
Mail::SPF::ENothingToParse, Mail::SPF::EInvalidMod
Abstract. Creates a new SPF record modifier object by parsing the
string and any options given.
Class methods
The following class methods are provided:
name_pattern: returns Regexp
Returns a regular expression that matches any legal modifier name.
Instance methods
The following instance methods are provided:
text: returns string; throws Mail::SPF::ENoUnparsedText
Returns the unparsed text of the modifier. Throws a
Mail::SPF::ENoUnparsedText exception if the modifier was created
synthetically instead of being parsed, and no text was provided.
name: returns string
Returns the name of the modifier.
params: returns string
Abstract. Returns the modifier's parameters formatted as a string.
A sub-class of Mail::SPF::Mod does not have to implement this
method if it supports no parameters, although this is highly
unlikely.
stringify: returns string
Formats the modifier's name and parameters as a string and returns
it. You can simply use a Mail::SPF::Mod object as a string for the
same effect, see "OVERLOADING".
process: throws Mail::SPF::Result, Mail::SPF::Result::Error,
Mail::SPF::Exception
Abstract. Processes the modifier. What that means depends on the
actual implementation in sub-classes. See "MODIFIER TYPES" below.
This method is abstract and must be implemented by sub-classes of
Mail::SPF::Mod.
MODIFIER TYPES
There are different basic types of modifiers, which are described
below. All of them are provided by the Mail::SPF::Mod module.
Global modifiers - Mail::SPF::GlobalMod
SPFv1 (RFC 4408) only knows "global" modifiers. A global modifier may
appear anywhere in an SPF record, but only once. During evaluation of
the record, global modifiers are processed after the last mechanism has
been evaluated and an SPF result has been determined.
The following additional class method is provided by
Mail::SPF::GlobalMod:
precedence: returns real
Abstract. Returns a real number between 0 and 1 denoting the
precedence of the type of the global modifier. Global modifiers
present in an SPF record are processed in the order of their
precedence values, 0 meaning "first".
This method is abstract and must be implemented by sub-classes of
Mail::SPF::GlobalMod.
The following specific instance method is provided by
Mail::SPF::GlobalMod:
process($server, $request, $result): throws Mail::SPF::Result
Abstract. Processes the modifier. What that means depends on the
actual implementation in sub-classes. Takes both a
Mail::SPF::Server and a Mail::SPF::Request object. As global
modifiers are generally processed after an SPF result has already
been determined, takes also the current Mail::SPF::Result. If the
modifier wishes to modify the SPF result, it may throw a different
Mail::SPF::Result object.
This method is abstract and must be implemented by sub-classes of
Mail::SPF::GlobalMod.
Positional modifiers - Mail::SPF::PositionalMod
Sender ID (RFC 4406) introduces the concept of "positional" modifiers.
According to RFC 4406, a positional modifier must follow a mechanism
and applies to that, and only that, mechanism. However, because this
definition is not very useful, and because no positional modifiers have
been defined based on it as of yet, Mail::SPF deviates from RFC 4406 as
follows:
A positional modifier may appear anywhere in an SPF record, and it is
stateful, i.e. it applies to all mechanisms and modifiers that follow
it. Positional modifiers are generally multiple, i.e. they may appear
any number of times throughout the record. During evaluation of the
record, positional modifiers are processed at exactly the time when
they are encountered by the evaluator. Consequently, all positional
modifiers are processed before an SPF result is determined.
The following specific instance method is provided by
Mail::SPF::PositionalMod:
process($server, $request): throws Mail::SPF::Result::Error,
Mail::SPF::Exception
Abstract. Processes the modifier. What that means depends on the
actual implementation in sub-classes. Takes both a
Mail::SPF::Server and a Mail::SPF::Request object. As global
modifiers are generally processed before an SPF result has been
determined, no result object is available to the modifier. The
modifier can (at least at this time) not directly modify the final
SPF result, however it may throw an exception to signal an error
condition.
This method is abstract and must be implemented by sub-classes of
Mail::SPF::PositionalMod.
Unknown modifiers - Mail::SPF::UnknownMod
Both SPFv1 and Sender ID allow unknown modifiers to appear in SPF
records in order to allow new modifiers to be introduced without
breaking existing implementations. Obviously, unknown modifiers are
neither global nor positional, but they may appear any number of times
throughout the record and are simply ignored during evaluation of the
record.
Also obviously, Mail::SPF::UnknownMod does not support a "process"
method.
The following specific instance method is provided by
Mail::SPF::UnknownMod:
params: returns string
Returns the modifier's unparsed value as a string.
OVERLOADING
If a Mail::SPF::Mod object is used as a string, the "stringify" method
is used to convert the object into a string.
SEE ALSO
Mail::SPF::Mod::Redirect, Mail::SPF::Mod::Exp
Mail::SPF, Mail::SPF::Record, Mail::SPF::Term
<http://tools.ietf.org/html/rfc4408>
For availability, support, and license information, see the README file
included with Mail::SPF.
AUTHORS
Julian Mehnle <julian@mehnle.net>, Shevek <cpan@anarres.org>
perl v5.16.2 2013-08-25 Mail::SPF::Mod(3)
