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94 | When called in void context, nothing is returned. In other contexts, |
94 | When called in void context, nothing is returned. In other contexts, |
95 | C<http_request> returns a "cancellation guard" - you have to keep the |
95 | C<http_request> returns a "cancellation guard" - you have to keep the |
96 | object at least alive until the callback get called. If the object gets |
96 | object at least alive until the callback get called. If the object gets |
97 | destroyed before the callbakc is called, the request will be cancelled. |
97 | destroyed before the callbakc is called, the request will be cancelled. |
98 | |
98 | |
99 | The callback will be called with the response data as first argument |
99 | The callback will be called with the response body data as first argument |
100 | (or C<undef> if it wasn't available due to errors), and a hash-ref with |
100 | (or C<undef> if an error occured), and a hash-ref with response headers as |
101 | response headers as second argument. |
101 | second argument. |
102 | |
102 | |
103 | All the headers in that hash are lowercased. In addition to the response |
103 | All the headers in that hash are lowercased. In addition to the response |
104 | headers, the "pseudo-headers" C<HTTPVersion>, C<Status> and C<Reason> |
104 | headers, the "pseudo-headers" C<HTTPVersion>, C<Status> and C<Reason> |
105 | contain the three parts of the HTTP Status-Line of the same name. The |
105 | contain the three parts of the HTTP Status-Line of the same name. The |
106 | pseudo-header C<URL> contains the original URL (which can differ from the |
106 | pseudo-header C<URL> contains the original URL (which can differ from the |
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186 | verification) TLS context. |
186 | verification) TLS context. |
187 | |
187 | |
188 | The default for this option is C<low>, which could be interpreted as "give |
188 | The default for this option is C<low>, which could be interpreted as "give |
189 | me the page, no matter what". |
189 | me the page, no matter what". |
190 | |
190 | |
191 | =item on_header => $callback->($hdr) |
191 | =item on_header => $callback->($headers) |
192 | |
192 | |
193 | When specified, this callback will be called with the header hash as soon |
193 | When specified, this callback will be called with the header hash as soon |
194 | as headers have been successfully received from the remote server (not on |
194 | as headers have been successfully received from the remote server (not on |
195 | locally-generated errors). |
195 | locally-generated errors). |
196 | |
196 | |
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200 | |
200 | |
201 | This callback is useful, among other things, to quickly reject unwanted |
201 | This callback is useful, among other things, to quickly reject unwanted |
202 | content, which, if it is supposed to be rare, can be faster than first |
202 | content, which, if it is supposed to be rare, can be faster than first |
203 | doing a C<HEAD> request. |
203 | doing a C<HEAD> request. |
204 | |
204 | |
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205 | Example: cancel the request unless the content-type is "text/html". |
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206 | |
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207 | on_header => sub { |
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208 | $_[0]{"content-type"} =~ /^text\/html\s*(?:;|$)/ |
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209 | }, |
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210 | |
205 | =item on_body => $callback->($data, $hdr) |
211 | =item on_body => $callback->($partial_body, $headers) |
206 | |
212 | |
207 | When specified, all body data will be "filtered" through this callback. |
213 | When specified, all body data will be passed to this callback instead of |
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214 | to the completion callback. The completion callback will get the empty |
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215 | string instead of the body data. |
208 | |
216 | |
209 | The callback will incrementally receive body data, and is supposed to |
217 | It has to return either true (in which case AnyEvent::HTTP will continue), |
210 | return it or a modified version of it (empty strings are valid returns). |
218 | or false, in which case AnyEvent::HTTP will cancel the download (and call |
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219 | the completion callback with an error code of C<598>). |
211 | |
220 | |
212 | If the callback returns C<undef>, then the request will be cancelled. |
221 | This callback is useful when the data is too large to be held in memory |
213 | |
222 | (so the callback writes it to a file) or when only some information should |
214 | This callback is useful when you want to do some processing on the data, |
223 | be extracted, or when the body should be processed incrementally. |
215 | or the data is too large to be held in memory (so the callback writes it |
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216 | to a file and returns the empty string) and so on. |
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217 | |
224 | |
218 | It is usually preferred over doing your own body handling via |
225 | It is usually preferred over doing your own body handling via |
219 | C<want_body_handle>. |
226 | C<want_body_handle>. |
220 | |
227 | |
221 | =item want_body_handle => $enable |
228 | =item want_body_handle => $enable |
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597 | my $len = $hdr{"content-length"}; |
604 | my $len = $hdr{"content-length"}; |
598 | |
605 | |
599 | if (!$redirect && $arg{on_header} && !$arg{on_header}(\%hdr)) { |
606 | if (!$redirect && $arg{on_header} && !$arg{on_header}(\%hdr)) { |
600 | $finish->(undef, { Status => 598, Reason => "Request cancelled by on_header", URL => $url }); |
607 | $finish->(undef, { Status => 598, Reason => "Request cancelled by on_header", URL => $url }); |
601 | } elsif ( |
608 | } elsif ( |
602 | $hdr{Status} =~ /^(?:1..|204|304)$/ |
609 | $hdr{Status} =~ /^(?:1..|[23]04)$/ |
603 | or $method eq "HEAD" |
610 | or $method eq "HEAD" |
604 | or (defined $len && !$len) |
611 | or (defined $len && !$len) |
605 | ) { |
612 | ) { |
606 | # no body |
613 | # no body |
607 | $finish->("", \%hdr); |
614 | $finish->("", \%hdr); |