Mail::Field(3pm)

1Mail::Field(3)        User Contributed Perl Documentation       Mail::Field(3)
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NAME

6       Mail::Field - Base class for manipulation of mail header fields
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INHERITANCE

9        Mail::Field is extended by
10          Mail::Field::AddrList
11          Mail::Field::Date
12          Mail::Field::Generic
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SYNOPSIS

15        use Mail::Field;
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17        my $field = Mail::Field->new('Subject', 'some subject text');
18        my $field = Mail::Field->new(Subject => 'some subject text');
19        print $field->tag,": ",$field->stringify,"\n";
20
21        my $field = Mail::Field->subject('some subject text');
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DESCRIPTION

24       "Mail::Field" creates and manipulates fields in MIME headers, collected
25       within a Mail::Header object.  Different field types have their own
26       sub-class (extension), defining additional useful accessors to the
27       field content.
28
29       People are invited to merge their implementation to special fields into
30       MailTools, to maintain a consistent set of packages and documentation.
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METHODS

33   Constructors
34       Mail::Field (and it's sub-classes) define several methods which return
35       new objects. These can all be categorized as constructor.
36
37       Mail::Field->combine(FIELDS)
38
39           Take a LIST of "Mail::Field" objects (which should all be of the
40           same sub-class) and create a new object in that same class.
41
42       Mail::Field->extract(TAG, HEAD [, INDEX ])
43
44           Takes as arguments the tag name, a "Mail::Head" object and
45           optionally an index.
46
47           If the index argument is given then "extract" will retrieve the
48           given tag from the "Mail::Head" object and create a new
49           "Mail::Field" based object.  undef will be returned in the field
50           does not exist.
51
52           If the index argument is not given the the result depends on the
53           context in which "extract" is called. If called in a scalar context
54           the result will be as if "extract" was called with an index value
55           of zero. If called in an array context then all tags will be
56           retrieved and a list of "Mail::Field" objects will be returned.
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58       Mail::Field->new(TAG [, STRING | OPTIONS])
59
60           Create an object in the class which defines the field specified by
61           the TAG argument.
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63   "Fake" constructors
64       $obj->create(OPTIONS)
65
66           This constructor is used internally with preprocessed field
67           information.  When called on an existing object, its original
68           content will get replaced.
69
70       $obj->parse
71
72           Parse a field line.
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74   Accessors
75       $obj->set(OPTIONS)
76
77           Change the settings (the content, but then smart) of this field.
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79       $obj->stringify
80
81           Returns the field as a string.
82
83       $obj->tag
84
85       Mail::Field->tag
86
87           Return the tag (in the correct case) for this item.  Well, actually
88           any casing is OK, because the field tags are treated case-
89           insentitive; however people have some preferences.
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91   Smart accessors
92       $obj->text([STRING])
93
94           Without arguments, the field is returned as stringify() does.
95           Otherwise, the STRING is parsed with parse() to replace the
96           object's content.
97
98           It is more clear to call either stringify() or parse() directly,
99           because this method does not add additional processing.
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DETAILS

102   SUB-CLASS PACKAGE NAMES
103       All sub-classes should be called Mail::Field::name where name is
104       derived from the tag using these rules.
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106       ·   Consider a tag as being made up of elements separated by '-'
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108       ·   Convert all characters to lowercase except the first in each
109           element, which should be uppercase.
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111       ·   name is then created from these elements by using the first N
112           characters from each element.
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114       ·   N is calculated by using the formula :-
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116               int((7 + #elements) / #elements)
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118       ·   name is then limited to a maximum of 8 characters, keeping the
119           first 8 characters.
120
121       For an example of this take a look at the definition of the
122       "_header_pkg_name()" subroutine in "Mail::Field"
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DIAGNOSTICS

125       Error: Undefined subroutine <method> called
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127           Mail::Field objects use autoloading to compile new functionality.
128           Apparently, the mehod called is not implemented for the specific
129           class of the field object.
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AUTHORS

136       The MailTools bundle was developed by Graham Barr.  Later, Mark
137       Overmeer took over maintenance without commitment to further
138       development.
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140       Mail::Cap by Gisle Aas <aas@oslonett.no>.  Mail::Field::AddrList by
141       Peter Orbaek <poe@cit.dk>.  Mail::Mailer and Mail::Send by Tim Bunce
142       <Tim.Bunce@ig.co.uk>.  For other contributors see ChangeLog.
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LICENSE

145       Copyrights 1995-2000 Graham Barr <gbarr@pobox.com> and 2001-2007 Mark
146       Overmeer <perl@overmeer.net>.
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148       This program is free software; you can redistribute it and/or modify it
149       under the same terms as Perl itself.  See
150       http://www.perl.com/perl/misc/Artistic.html
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154perl v5.10.1                      2008-07-29                    Mail::Field(3)