Commit | Line | Data |
3fea05b9 |
1 | package HTTP::Headers; |
2 | |
3 | use strict; |
4 | use Carp (); |
5 | |
6 | use vars qw($VERSION $TRANSLATE_UNDERSCORE); |
7 | $VERSION = "5.827"; |
8 | |
9 | # The $TRANSLATE_UNDERSCORE variable controls whether '_' can be used |
10 | # as a replacement for '-' in header field names. |
11 | $TRANSLATE_UNDERSCORE = 1 unless defined $TRANSLATE_UNDERSCORE; |
12 | |
13 | # "Good Practice" order of HTTP message headers: |
14 | # - General-Headers |
15 | # - Request-Headers |
16 | # - Response-Headers |
17 | # - Entity-Headers |
18 | |
19 | my @general_headers = qw( |
20 | Cache-Control Connection Date Pragma Trailer Transfer-Encoding Upgrade |
21 | Via Warning |
22 | ); |
23 | |
24 | my @request_headers = qw( |
25 | Accept Accept-Charset Accept-Encoding Accept-Language |
26 | Authorization Expect From Host |
27 | If-Match If-Modified-Since If-None-Match If-Range If-Unmodified-Since |
28 | Max-Forwards Proxy-Authorization Range Referer TE User-Agent |
29 | ); |
30 | |
31 | my @response_headers = qw( |
32 | Accept-Ranges Age ETag Location Proxy-Authenticate Retry-After Server |
33 | Vary WWW-Authenticate |
34 | ); |
35 | |
36 | my @entity_headers = qw( |
37 | Allow Content-Encoding Content-Language Content-Length Content-Location |
38 | Content-MD5 Content-Range Content-Type Expires Last-Modified |
39 | ); |
40 | |
41 | my %entity_header = map { lc($_) => 1 } @entity_headers; |
42 | |
43 | my @header_order = ( |
44 | @general_headers, |
45 | @request_headers, |
46 | @response_headers, |
47 | @entity_headers, |
48 | ); |
49 | |
50 | # Make alternative representations of @header_order. This is used |
51 | # for sorting and case matching. |
52 | my %header_order; |
53 | my %standard_case; |
54 | |
55 | { |
56 | my $i = 0; |
57 | for (@header_order) { |
58 | my $lc = lc $_; |
59 | $header_order{$lc} = ++$i; |
60 | $standard_case{$lc} = $_; |
61 | } |
62 | } |
63 | |
64 | |
65 | |
66 | sub new |
67 | { |
68 | my($class) = shift; |
69 | my $self = bless {}, $class; |
70 | $self->header(@_) if @_; # set up initial headers |
71 | $self; |
72 | } |
73 | |
74 | |
75 | sub header |
76 | { |
77 | my $self = shift; |
78 | Carp::croak('Usage: $h->header($field, ...)') unless @_; |
79 | my(@old); |
80 | my %seen; |
81 | while (@_) { |
82 | my $field = shift; |
83 | my $op = @_ ? ($seen{lc($field)}++ ? 'PUSH' : 'SET') : 'GET'; |
84 | @old = $self->_header($field, shift, $op); |
85 | } |
86 | return @old if wantarray; |
87 | return $old[0] if @old <= 1; |
88 | join(", ", @old); |
89 | } |
90 | |
91 | sub clear |
92 | { |
93 | my $self = shift; |
94 | %$self = (); |
95 | } |
96 | |
97 | |
98 | sub push_header |
99 | { |
100 | my $self = shift; |
101 | return $self->_header(@_, 'PUSH_H') if @_ == 2; |
102 | while (@_) { |
103 | $self->_header(splice(@_, 0, 2), 'PUSH_H'); |
104 | } |
105 | } |
106 | |
107 | |
108 | sub init_header |
109 | { |
110 | Carp::croak('Usage: $h->init_header($field, $val)') if @_ != 3; |
111 | shift->_header(@_, 'INIT'); |
112 | } |
113 | |
114 | |
115 | sub remove_header |
116 | { |
117 | my($self, @fields) = @_; |
118 | my $field; |
119 | my @values; |
120 | foreach $field (@fields) { |
121 | $field =~ tr/_/-/ if $field !~ /^:/ && $TRANSLATE_UNDERSCORE; |
122 | my $v = delete $self->{lc $field}; |
123 | push(@values, ref($v) eq 'ARRAY' ? @$v : $v) if defined $v; |
124 | } |
125 | return @values; |
126 | } |
127 | |
128 | sub remove_content_headers |
129 | { |
130 | my $self = shift; |
131 | unless (defined(wantarray)) { |
132 | # fast branch that does not create return object |
133 | delete @$self{grep $entity_header{$_} || /^content-/, keys %$self}; |
134 | return; |
135 | } |
136 | |
137 | my $c = ref($self)->new; |
138 | for my $f (grep $entity_header{$_} || /^content-/, keys %$self) { |
139 | $c->{$f} = delete $self->{$f}; |
140 | } |
141 | $c; |
142 | } |
143 | |
144 | |
145 | sub _header |
146 | { |
147 | my($self, $field, $val, $op) = @_; |
148 | |
149 | unless ($field =~ /^:/) { |
150 | $field =~ tr/_/-/ if $TRANSLATE_UNDERSCORE; |
151 | my $old = $field; |
152 | $field = lc $field; |
153 | unless(defined $standard_case{$field}) { |
154 | # generate a %standard_case entry for this field |
155 | $old =~ s/\b(\w)/\u$1/g; |
156 | $standard_case{$field} = $old; |
157 | } |
158 | } |
159 | |
160 | $op ||= defined($val) ? 'SET' : 'GET'; |
161 | if ($op eq 'PUSH_H') { |
162 | # Like PUSH but where we don't care about the return value |
163 | if (exists $self->{$field}) { |
164 | my $h = $self->{$field}; |
165 | if (ref($h) eq 'ARRAY') { |
166 | push(@$h, ref($val) eq "ARRAY" ? @$val : $val); |
167 | } |
168 | else { |
169 | $self->{$field} = [$h, ref($val) eq "ARRAY" ? @$val : $val] |
170 | } |
171 | return; |
172 | } |
173 | $self->{$field} = $val; |
174 | return; |
175 | } |
176 | |
177 | my $h = $self->{$field}; |
178 | my @old = ref($h) eq 'ARRAY' ? @$h : (defined($h) ? ($h) : ()); |
179 | |
180 | unless ($op eq 'GET' || ($op eq 'INIT' && @old)) { |
181 | if (defined($val)) { |
182 | my @new = ($op eq 'PUSH') ? @old : (); |
183 | if (ref($val) ne 'ARRAY') { |
184 | push(@new, $val); |
185 | } |
186 | else { |
187 | push(@new, @$val); |
188 | } |
189 | $self->{$field} = @new > 1 ? \@new : $new[0]; |
190 | } |
191 | elsif ($op ne 'PUSH') { |
192 | delete $self->{$field}; |
193 | } |
194 | } |
195 | @old; |
196 | } |
197 | |
198 | |
199 | sub _sorted_field_names |
200 | { |
201 | my $self = shift; |
202 | return sort { |
203 | ($header_order{$a} || 999) <=> ($header_order{$b} || 999) || |
204 | $a cmp $b |
205 | } keys %$self |
206 | } |
207 | |
208 | |
209 | sub header_field_names { |
210 | my $self = shift; |
211 | return map $standard_case{$_} || $_, $self->_sorted_field_names |
212 | if wantarray; |
213 | return keys %$self; |
214 | } |
215 | |
216 | |
217 | sub scan |
218 | { |
219 | my($self, $sub) = @_; |
220 | my $key; |
221 | foreach $key ($self->_sorted_field_names) { |
222 | next if $key =~ /^_/; |
223 | my $vals = $self->{$key}; |
224 | if (ref($vals) eq 'ARRAY') { |
225 | my $val; |
226 | for $val (@$vals) { |
227 | &$sub($standard_case{$key} || $key, $val); |
228 | } |
229 | } |
230 | else { |
231 | &$sub($standard_case{$key} || $key, $vals); |
232 | } |
233 | } |
234 | } |
235 | |
236 | |
237 | sub as_string |
238 | { |
239 | my($self, $endl) = @_; |
240 | $endl = "\n" unless defined $endl; |
241 | |
242 | my @result = (); |
243 | $self->scan(sub { |
244 | my($field, $val) = @_; |
245 | $field =~ s/^://; |
246 | if ($val =~ /\n/) { |
247 | # must handle header values with embedded newlines with care |
248 | $val =~ s/\s+$//; # trailing newlines and space must go |
249 | $val =~ s/\n\n+/\n/g; # no empty lines |
250 | $val =~ s/\n([^\040\t])/\n $1/g; # intial space for continuation |
251 | $val =~ s/\n/$endl/g; # substitute with requested line ending |
252 | } |
253 | push(@result, "$field: $val"); |
254 | }); |
255 | |
256 | join($endl, @result, ''); |
257 | } |
258 | |
259 | |
260 | if (eval { require Storable; 1 }) { |
261 | *clone = \&Storable::dclone; |
262 | } else { |
263 | *clone = sub { |
264 | my $self = shift; |
265 | my $clone = new HTTP::Headers; |
266 | $self->scan(sub { $clone->push_header(@_);} ); |
267 | $clone; |
268 | }; |
269 | } |
270 | |
271 | |
272 | sub _date_header |
273 | { |
274 | require HTTP::Date; |
275 | my($self, $header, $time) = @_; |
276 | my($old) = $self->_header($header); |
277 | if (defined $time) { |
278 | $self->_header($header, HTTP::Date::time2str($time)); |
279 | } |
280 | $old =~ s/;.*// if defined($old); |
281 | HTTP::Date::str2time($old); |
282 | } |
283 | |
284 | |
285 | sub date { shift->_date_header('Date', @_); } |
286 | sub expires { shift->_date_header('Expires', @_); } |
287 | sub if_modified_since { shift->_date_header('If-Modified-Since', @_); } |
288 | sub if_unmodified_since { shift->_date_header('If-Unmodified-Since', @_); } |
289 | sub last_modified { shift->_date_header('Last-Modified', @_); } |
290 | |
291 | # This is used as a private LWP extension. The Client-Date header is |
292 | # added as a timestamp to a response when it has been received. |
293 | sub client_date { shift->_date_header('Client-Date', @_); } |
294 | |
295 | # The retry_after field is dual format (can also be a expressed as |
296 | # number of seconds from now), so we don't provide an easy way to |
297 | # access it until we have know how both these interfaces can be |
298 | # addressed. One possibility is to return a negative value for |
299 | # relative seconds and a positive value for epoch based time values. |
300 | #sub retry_after { shift->_date_header('Retry-After', @_); } |
301 | |
302 | sub content_type { |
303 | my $self = shift; |
304 | my $ct = $self->{'content-type'}; |
305 | $self->{'content-type'} = shift if @_; |
306 | $ct = $ct->[0] if ref($ct) eq 'ARRAY'; |
307 | return '' unless defined($ct) && length($ct); |
308 | my @ct = split(/;\s*/, $ct, 2); |
309 | for ($ct[0]) { |
310 | s/\s+//g; |
311 | $_ = lc($_); |
312 | } |
313 | wantarray ? @ct : $ct[0]; |
314 | } |
315 | |
316 | sub content_type_charset { |
317 | my $self = shift; |
318 | require HTTP::Headers::Util; |
319 | my $h = $self->{'content-type'}; |
320 | $h = $h->[0] if ref($h); |
321 | $h = "" unless defined $h; |
322 | my @v = HTTP::Headers::Util::split_header_words($h); |
323 | if (@v) { |
324 | my($ct, undef, %ct_param) = @{$v[0]}; |
325 | my $charset = $ct_param{charset}; |
326 | if ($ct) { |
327 | $ct = lc($ct); |
328 | $ct =~ s/\s+//; |
329 | } |
330 | if ($charset) { |
331 | $charset = uc($charset); |
332 | $charset =~ s/^\s+//; $charset =~ s/\s+\z//; |
333 | undef($charset) if $charset eq ""; |
334 | } |
335 | return $ct, $charset if wantarray; |
336 | return $charset; |
337 | } |
338 | return undef, undef if wantarray; |
339 | return undef; |
340 | } |
341 | |
342 | sub content_is_text { |
343 | my $self = shift; |
344 | return $self->content_type =~ m,^text/,; |
345 | } |
346 | |
347 | sub content_is_html { |
348 | my $self = shift; |
349 | return $self->content_type eq 'text/html' || $self->content_is_xhtml; |
350 | } |
351 | |
352 | sub content_is_xhtml { |
353 | my $ct = shift->content_type; |
354 | return $ct eq "application/xhtml+xml" || |
355 | $ct eq "application/vnd.wap.xhtml+xml"; |
356 | } |
357 | |
358 | sub content_is_xml { |
359 | my $ct = shift->content_type; |
360 | return 1 if $ct eq "text/xml"; |
361 | return 1 if $ct eq "application/xml"; |
362 | return 1 if $ct =~ /\+xml$/; |
363 | return 0; |
364 | } |
365 | |
366 | sub referer { |
367 | my $self = shift; |
368 | if (@_ && $_[0] =~ /#/) { |
369 | # Strip fragment per RFC 2616, section 14.36. |
370 | my $uri = shift; |
371 | if (ref($uri)) { |
372 | $uri = $uri->clone; |
373 | $uri->fragment(undef); |
374 | } |
375 | else { |
376 | $uri =~ s/\#.*//; |
377 | } |
378 | unshift @_, $uri; |
379 | } |
380 | ($self->_header('Referer', @_))[0]; |
381 | } |
382 | *referrer = \&referer; # on tchrist's request |
383 | |
384 | sub title { (shift->_header('Title', @_))[0] } |
385 | sub content_encoding { (shift->_header('Content-Encoding', @_))[0] } |
386 | sub content_language { (shift->_header('Content-Language', @_))[0] } |
387 | sub content_length { (shift->_header('Content-Length', @_))[0] } |
388 | |
389 | sub user_agent { (shift->_header('User-Agent', @_))[0] } |
390 | sub server { (shift->_header('Server', @_))[0] } |
391 | |
392 | sub from { (shift->_header('From', @_))[0] } |
393 | sub warning { (shift->_header('Warning', @_))[0] } |
394 | |
395 | sub www_authenticate { (shift->_header('WWW-Authenticate', @_))[0] } |
396 | sub authorization { (shift->_header('Authorization', @_))[0] } |
397 | |
398 | sub proxy_authenticate { (shift->_header('Proxy-Authenticate', @_))[0] } |
399 | sub proxy_authorization { (shift->_header('Proxy-Authorization', @_))[0] } |
400 | |
401 | sub authorization_basic { shift->_basic_auth("Authorization", @_) } |
402 | sub proxy_authorization_basic { shift->_basic_auth("Proxy-Authorization", @_) } |
403 | |
404 | sub _basic_auth { |
405 | require MIME::Base64; |
406 | my($self, $h, $user, $passwd) = @_; |
407 | my($old) = $self->_header($h); |
408 | if (defined $user) { |
409 | Carp::croak("Basic authorization user name can't contain ':'") |
410 | if $user =~ /:/; |
411 | $passwd = '' unless defined $passwd; |
412 | $self->_header($h => 'Basic ' . |
413 | MIME::Base64::encode("$user:$passwd", '')); |
414 | } |
415 | if (defined $old && $old =~ s/^\s*Basic\s+//) { |
416 | my $val = MIME::Base64::decode($old); |
417 | return $val unless wantarray; |
418 | return split(/:/, $val, 2); |
419 | } |
420 | return; |
421 | } |
422 | |
423 | |
424 | 1; |
425 | |
426 | __END__ |
427 | |
428 | =head1 NAME |
429 | |
430 | HTTP::Headers - Class encapsulating HTTP Message headers |
431 | |
432 | =head1 SYNOPSIS |
433 | |
434 | require HTTP::Headers; |
435 | $h = HTTP::Headers->new; |
436 | |
437 | $h->header('Content-Type' => 'text/plain'); # set |
438 | $ct = $h->header('Content-Type'); # get |
439 | $h->remove_header('Content-Type'); # delete |
440 | |
441 | =head1 DESCRIPTION |
442 | |
443 | The C<HTTP::Headers> class encapsulates HTTP-style message headers. |
444 | The headers consist of attribute-value pairs also called fields, which |
445 | may be repeated, and which are printed in a particular order. The |
446 | field names are cases insensitive. |
447 | |
448 | Instances of this class are usually created as member variables of the |
449 | C<HTTP::Request> and C<HTTP::Response> classes, internal to the |
450 | library. |
451 | |
452 | The following methods are available: |
453 | |
454 | =over 4 |
455 | |
456 | =item $h = HTTP::Headers->new |
457 | |
458 | Constructs a new C<HTTP::Headers> object. You might pass some initial |
459 | attribute-value pairs as parameters to the constructor. I<E.g.>: |
460 | |
461 | $h = HTTP::Headers->new( |
462 | Date => 'Thu, 03 Feb 1994 00:00:00 GMT', |
463 | Content_Type => 'text/html; version=3.2', |
464 | Content_Base => 'http://www.perl.org/'); |
465 | |
466 | The constructor arguments are passed to the C<header> method which is |
467 | described below. |
468 | |
469 | =item $h->clone |
470 | |
471 | Returns a copy of this C<HTTP::Headers> object. |
472 | |
473 | =item $h->header( $field ) |
474 | |
475 | =item $h->header( $field => $value ) |
476 | |
477 | =item $h->header( $f1 => $v1, $f2 => $v2, ... ) |
478 | |
479 | Get or set the value of one or more header fields. The header field |
480 | name ($field) is not case sensitive. To make the life easier for perl |
481 | users who wants to avoid quoting before the => operator, you can use |
482 | '_' as a replacement for '-' in header names. |
483 | |
484 | The header() method accepts multiple ($field => $value) pairs, which |
485 | means that you can update several fields with a single invocation. |
486 | |
487 | The $value argument may be a plain string or a reference to an array |
488 | of strings for a multi-valued field. If the $value is provided as |
489 | C<undef> then the field is removed. If the $value is not given, then |
490 | that header field will remain unchanged. |
491 | |
492 | The old value (or values) of the last of the header fields is returned. |
493 | If no such field exists C<undef> will be returned. |
494 | |
495 | A multi-valued field will be returned as separate values in list |
496 | context and will be concatenated with ", " as separator in scalar |
497 | context. The HTTP spec (RFC 2616) promise that joining multiple |
498 | values in this way will not change the semantic of a header field, but |
499 | in practice there are cases like old-style Netscape cookies (see |
500 | L<HTTP::Cookies>) where "," is used as part of the syntax of a single |
501 | field value. |
502 | |
503 | Examples: |
504 | |
505 | $header->header(MIME_Version => '1.0', |
506 | User_Agent => 'My-Web-Client/0.01'); |
507 | $header->header(Accept => "text/html, text/plain, image/*"); |
508 | $header->header(Accept => [qw(text/html text/plain image/*)]); |
509 | @accepts = $header->header('Accept'); # get multiple values |
510 | $accepts = $header->header('Accept'); # get values as a single string |
511 | |
512 | =item $h->push_header( $field => $value ) |
513 | |
514 | =item $h->push_header( $f1 => $v1, $f2 => $v2, ... ) |
515 | |
516 | Add a new field value for the specified header field. Previous values |
517 | for the same field are retained. |
518 | |
519 | As for the header() method, the field name ($field) is not case |
520 | sensitive and '_' can be used as a replacement for '-'. |
521 | |
522 | The $value argument may be a scalar or a reference to a list of |
523 | scalars. |
524 | |
525 | $header->push_header(Accept => 'image/jpeg'); |
526 | $header->push_header(Accept => [map "image/$_", qw(gif png tiff)]); |
527 | |
528 | =item $h->init_header( $field => $value ) |
529 | |
530 | Set the specified header to the given value, but only if no previous |
531 | value for that field is set. |
532 | |
533 | The header field name ($field) is not case sensitive and '_' |
534 | can be used as a replacement for '-'. |
535 | |
536 | The $value argument may be a scalar or a reference to a list of |
537 | scalars. |
538 | |
539 | =item $h->remove_header( $field, ... ) |
540 | |
541 | This function removes the header fields with the specified names. |
542 | |
543 | The header field names ($field) are not case sensitive and '_' |
544 | can be used as a replacement for '-'. |
545 | |
546 | The return value is the values of the fields removed. In scalar |
547 | context the number of fields removed is returned. |
548 | |
549 | Note that if you pass in multiple field names then it is generally not |
550 | possible to tell which of the returned values belonged to which field. |
551 | |
552 | =item $h->remove_content_headers |
553 | |
554 | This will remove all the header fields used to describe the content of |
555 | a message. All header field names prefixed with C<Content-> falls |
556 | into this category, as well as C<Allow>, C<Expires> and |
557 | C<Last-Modified>. RFC 2616 denote these fields as I<Entity Header |
558 | Fields>. |
559 | |
560 | The return value is a new C<HTTP::Headers> object that contains the |
561 | removed headers only. |
562 | |
563 | =item $h->clear |
564 | |
565 | This will remove all header fields. |
566 | |
567 | =item $h->header_field_names |
568 | |
569 | Returns the list of distinct names for the fields present in the |
570 | header. The field names have case as suggested by HTTP spec, and the |
571 | names are returned in the recommended "Good Practice" order. |
572 | |
573 | In scalar context return the number of distinct field names. |
574 | |
575 | =item $h->scan( \&process_header_field ) |
576 | |
577 | Apply a subroutine to each header field in turn. The callback routine |
578 | is called with two parameters; the name of the field and a single |
579 | value (a string). If a header field is multi-valued, then the |
580 | routine is called once for each value. The field name passed to the |
581 | callback routine has case as suggested by HTTP spec, and the headers |
582 | will be visited in the recommended "Good Practice" order. |
583 | |
584 | Any return values of the callback routine are ignored. The loop can |
585 | be broken by raising an exception (C<die>), but the caller of scan() |
586 | would have to trap the exception itself. |
587 | |
588 | =item $h->as_string |
589 | |
590 | =item $h->as_string( $eol ) |
591 | |
592 | Return the header fields as a formatted MIME header. Since it |
593 | internally uses the C<scan> method to build the string, the result |
594 | will use case as suggested by HTTP spec, and it will follow |
595 | recommended "Good Practice" of ordering the header fields. Long header |
596 | values are not folded. |
597 | |
598 | The optional $eol parameter specifies the line ending sequence to |
599 | use. The default is "\n". Embedded "\n" characters in header field |
600 | values will be substituted with this line ending sequence. |
601 | |
602 | =back |
603 | |
604 | =head1 CONVENIENCE METHODS |
605 | |
606 | The most frequently used headers can also be accessed through the |
607 | following convenience Methods. Most of these methods can both be used to read |
608 | and to set the value of a header. The header value is set if you pass |
609 | an argument to the method. The old header value is always returned. |
610 | If the given header did not exist then C<undef> is returned. |
611 | |
612 | Methods that deal with dates/times always convert their value to system |
613 | time (seconds since Jan 1, 1970) and they also expect this kind of |
614 | value when the header value is set. |
615 | |
616 | =over 4 |
617 | |
618 | =item $h->date |
619 | |
620 | This header represents the date and time at which the message was |
621 | originated. I<E.g.>: |
622 | |
623 | $h->date(time); # set current date |
624 | |
625 | =item $h->expires |
626 | |
627 | This header gives the date and time after which the entity should be |
628 | considered stale. |
629 | |
630 | =item $h->if_modified_since |
631 | |
632 | =item $h->if_unmodified_since |
633 | |
634 | These header fields are used to make a request conditional. If the requested |
635 | resource has (or has not) been modified since the time specified in this field, |
636 | then the server will return a C<304 Not Modified> response instead of |
637 | the document itself. |
638 | |
639 | =item $h->last_modified |
640 | |
641 | This header indicates the date and time at which the resource was last |
642 | modified. I<E.g.>: |
643 | |
644 | # check if document is more than 1 hour old |
645 | if (my $last_mod = $h->last_modified) { |
646 | if ($last_mod < time - 60*60) { |
647 | ... |
648 | } |
649 | } |
650 | |
651 | =item $h->content_type |
652 | |
653 | The Content-Type header field indicates the media type of the message |
654 | content. I<E.g.>: |
655 | |
656 | $h->content_type('text/html'); |
657 | |
658 | The value returned will be converted to lower case, and potential |
659 | parameters will be chopped off and returned as a separate value if in |
660 | an array context. If there is no such header field, then the empty |
661 | string is returned. This makes it safe to do the following: |
662 | |
663 | if ($h->content_type eq 'text/html') { |
664 | # we enter this place even if the real header value happens to |
665 | # be 'TEXT/HTML; version=3.0' |
666 | ... |
667 | } |
668 | |
669 | =item $h->content_type_charset |
670 | |
671 | Returns the upper-cased charset specified in the Content-Type header. In list |
672 | context return the lower-cased bare content type followed by the upper-cased |
673 | charset. Both values will be C<undef> if not specified in the header. |
674 | |
675 | =item $h->content_is_text |
676 | |
677 | Returns TRUE if the Content-Type header field indicate that the |
678 | content is textual. |
679 | |
680 | =item $h->content_is_html |
681 | |
682 | Returns TRUE if the Content-Type header field indicate that the |
683 | content is some kind of HTML (including XHTML). This method can't be |
684 | used to set Content-Type. |
685 | |
686 | =item $h->content_is_xhtml |
687 | |
688 | Returns TRUE if the Content-Type header field indicate that the |
689 | content is XHTML. This method can't be used to set Content-Type. |
690 | |
691 | =item $h->content_is_xml |
692 | |
693 | Returns TRUE if the Content-Type header field indicate that the |
694 | content is XML. This method can't be used to set Content-Type. |
695 | |
696 | =item $h->content_encoding |
697 | |
698 | The Content-Encoding header field is used as a modifier to the |
699 | media type. When present, its value indicates what additional |
700 | encoding mechanism has been applied to the resource. |
701 | |
702 | =item $h->content_length |
703 | |
704 | A decimal number indicating the size in bytes of the message content. |
705 | |
706 | =item $h->content_language |
707 | |
708 | The natural language(s) of the intended audience for the message |
709 | content. The value is one or more language tags as defined by RFC |
710 | 1766. Eg. "no" for some kind of Norwegian and "en-US" for English the |
711 | way it is written in the US. |
712 | |
713 | =item $h->title |
714 | |
715 | The title of the document. In libwww-perl this header will be |
716 | initialized automatically from the E<lt>TITLE>...E<lt>/TITLE> element |
717 | of HTML documents. I<This header is no longer part of the HTTP |
718 | standard.> |
719 | |
720 | =item $h->user_agent |
721 | |
722 | This header field is used in request messages and contains information |
723 | about the user agent originating the request. I<E.g.>: |
724 | |
725 | $h->user_agent('Mozilla/5.0 (compatible; MSIE 7.0; Windows NT 6.0)'); |
726 | |
727 | =item $h->server |
728 | |
729 | The server header field contains information about the software being |
730 | used by the originating server program handling the request. |
731 | |
732 | =item $h->from |
733 | |
734 | This header should contain an Internet e-mail address for the human |
735 | user who controls the requesting user agent. The address should be |
736 | machine-usable, as defined by RFC822. E.g.: |
737 | |
738 | $h->from('King Kong <king@kong.com>'); |
739 | |
740 | I<This header is no longer part of the HTTP standard.> |
741 | |
742 | =item $h->referer |
743 | |
744 | Used to specify the address (URI) of the document from which the |
745 | requested resource address was obtained. |
746 | |
747 | The "Free On-line Dictionary of Computing" as this to say about the |
748 | word I<referer>: |
749 | |
750 | <World-Wide Web> A misspelling of "referrer" which |
751 | somehow made it into the {HTTP} standard. A given {web |
752 | page}'s referer (sic) is the {URL} of whatever web page |
753 | contains the link that the user followed to the current |
754 | page. Most browsers pass this information as part of a |
755 | request. |
756 | |
757 | (1998-10-19) |
758 | |
759 | By popular demand C<referrer> exists as an alias for this method so you |
760 | can avoid this misspelling in your programs and still send the right |
761 | thing on the wire. |
762 | |
763 | When setting the referrer, this method removes the fragment from the |
764 | given URI if it is present, as mandated by RFC2616. Note that |
765 | the removal does I<not> happen automatically if using the header(), |
766 | push_header() or init_header() methods to set the referrer. |
767 | |
768 | =item $h->www_authenticate |
769 | |
770 | This header must be included as part of a C<401 Unauthorized> response. |
771 | The field value consist of a challenge that indicates the |
772 | authentication scheme and parameters applicable to the requested URI. |
773 | |
774 | =item $h->proxy_authenticate |
775 | |
776 | This header must be included in a C<407 Proxy Authentication Required> |
777 | response. |
778 | |
779 | =item $h->authorization |
780 | |
781 | =item $h->proxy_authorization |
782 | |
783 | A user agent that wishes to authenticate itself with a server or a |
784 | proxy, may do so by including these headers. |
785 | |
786 | =item $h->authorization_basic |
787 | |
788 | This method is used to get or set an authorization header that use the |
789 | "Basic Authentication Scheme". In array context it will return two |
790 | values; the user name and the password. In scalar context it will |
791 | return I<"uname:password"> as a single string value. |
792 | |
793 | When used to set the header value, it expects two arguments. I<E.g.>: |
794 | |
795 | $h->authorization_basic($uname, $password); |
796 | |
797 | The method will croak if the $uname contains a colon ':'. |
798 | |
799 | =item $h->proxy_authorization_basic |
800 | |
801 | Same as authorization_basic() but will set the "Proxy-Authorization" |
802 | header instead. |
803 | |
804 | =back |
805 | |
806 | =head1 NON-CANONICALIZED FIELD NAMES |
807 | |
808 | The header field name spelling is normally canonicalized including the |
809 | '_' to '-' translation. There are some application where this is not |
810 | appropriate. Prefixing field names with ':' allow you to force a |
811 | specific spelling. For example if you really want a header field name |
812 | to show up as C<foo_bar> instead of "Foo-Bar", you might set it like |
813 | this: |
814 | |
815 | $h->header(":foo_bar" => 1); |
816 | |
817 | These field names are returned with the ':' intact for |
818 | $h->header_field_names and the $h->scan callback, but the colons do |
819 | not show in $h->as_string. |
820 | |
821 | =head1 COPYRIGHT |
822 | |
823 | Copyright 1995-2005 Gisle Aas. |
824 | |
825 | This library is free software; you can redistribute it and/or |
826 | modify it under the same terms as Perl itself. |
827 | |