/[Grep]/lib/Grep/Source.pm
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Revision 130 - (show annotations)
Sun Apr 29 12:07:06 2007 UTC (17 years ago) by dpavlin
File size: 8332 byte(s)
remove debugging snippet
1 # Dobrica Pavlinusic, <dpavlin@rot13.org> 02/22/07 20:30:00 CET
2
3 use strict;
4 use warnings;
5
6 package Grep::Source;
7
8 use Carp qw/verbose/;
9 use Module::Pluggable search_path => 'Grep::Source', sub_name => 'sources', require => 1;
10 use base qw(Class::Accessor Jifty::Object);
11 Grep::Source->mk_accessors( qw(feed uri q new_items collection search_obj tree) );
12
13 use HTML::TreeBuilder;
14 use WWW::Mechanize;
15 use XML::Feed;
16 use URI;
17 use HTML::ResolveLink;
18
19 use Data::Dump qw/dump/;
20
21 =head1 NAME
22
23 Grep::Source - base class for implementation of different sources for Grep
24
25 =head1 METHODS
26
27 This is mostly documentation because most of methods are implemented by plugins.
28
29 =head2 sources
30
31 my @sources = Grep::Source->sources();
32
33 Returns all available sources.
34
35 =cut
36
37 Jifty->log->debug("Found source plugins: ", join(", ", __PACKAGE__->sources() ) );
38
39 =head2 new
40
41 my $source = Grep::Source->new({ feed => $feed_record });
42
43 This will also setup:
44
45 =head2 feed
46
47 isa L<Grep::Model::Feed>
48
49 =head2 search
50
51 my $collection = $source->search( 'query string' );
52
53 It will also setup following accessors:
54
55 =head2 q
56
57 Search query
58
59 =head2 uri
60
61 URI of feed with embedded search query
62
63 =head2 new_items
64
65 Number of new items in result collection
66
67 =head2 collection
68
69 Actuall results which is L<Grep::Model::ItemCollection>, so following will
70 work:
71
72 print "and ", $self->collection->count, " total items";
73
74
75 Also setups number of new items
76
77 print $source->new_items, " items new";
78
79 =cut
80
81 sub search {
82 my $self = shift;
83
84 my $q = shift;
85
86 $q ? $self->q( $q ) : $q = $self->q;
87
88 die "no q?" unless ( $self->q );
89 die "no feed?" unless ( $self->feed );
90 die "feed not Grep::Model::Feed" unless ( $self->feed->isa('Grep::Model::Feed') );
91
92 my $message;
93 my $uri = $self->feed->uri;
94 if ($uri =~ m/%s/) {
95 $uri = $self->feed->search_uri( $q );
96 $message = 'Searching';
97 } else {
98 $message = 'Fetching';
99 }
100 $message .= ' ' . $self->feed->title . " at $uri";
101
102 $self->uri( $uri );
103
104 $self->log->info( $message );
105
106 $self->collection( Grep::Model::ItemCollection->new() );
107
108 my $class = $self->feed->source || 'Grep::Source::Feed';
109 $self->log->debug("using $class");
110
111 $self->search_obj( Grep::Search->new() );
112 $self->log->debug("created " . $self->search_obj);
113
114 $class->fetch( $self );
115
116 $self->search_obj->finish;
117
118 return $self->collection;
119 }
120
121 =head2 add_record
122
123 Plugins will be called with parametar C<$parent> so they can call this method to add
124 record into result collection (and store in cache and index).
125
126 $parent->add_record( id => 42, foo => 'bar', ... );
127
128 This will also update L</new_items>
129
130 =cut
131
132 sub add_record {
133 my $self = shift;
134
135 $self->log->confess("no search_obj") unless ($self->search_obj);
136
137 my $i = Grep::Model::Item->new();
138
139 my $rec = {@_};
140
141 $self->log->debug("resolving links using base ", $rec->{link});
142 my $resolver = HTML::ResolveLink->new( base => $rec->{link} );
143 $rec->{content} = $resolver->resolve( $rec->{content} );
144
145 my ($ok,$msg) = $i->load_or_create( %$rec );
146
147 $msg ||= '';
148
149 if ( $ok ) {
150 $self->log->debug("item ", $i->id, ": $msg");
151 $self->collection->add_record( $i );
152
153 # is new record?
154 if ( $msg !~ m/^Found/ ) {
155 $self->search_obj->add( $i );
156 $self->new_items( ( $self->new_items || 0 ) + 1 );
157 }
158 } else {
159 warn "can't add entry ", dump( @_ ), "\n";
160 }
161 }
162
163 =head2 content_class
164
165 Return class registred for particular content.
166
167 my $class = $source->content_class( $content );
168
169 =cut
170
171 sub content_class {
172 my $self = shift;
173
174 my $content = shift or die "no content?";
175
176 foreach my $s ( $self->sources ) {
177 $self->log->debug("testing source class $s");
178 if ( $s->can('content_have') ) {
179 my $regex = $s->content_have( $content ) or
180 die "${s}->content_have didn't return anything";
181 die "${s}->content_have didn't return regex but ", dump( $regex ), " ref ", ref( $regex )
182 unless ( ref($regex) eq 'Regexp' );
183 if ( $content =~ $regex ) {
184 $self->log->debug("${s}->content_have succesful");
185 return $s;
186 }
187 }
188 }
189 }
190
191 =head2 scrape
192
193 Create semi-complex L<WWW::Mechanize> rules to scrape page
194
195
196 =cut
197
198 sub element_by_triplet {
199 my $self = shift;
200
201 my $args = {@_};
202
203 my $tree = $args->{tree} || die "no tree";
204 my $message = $args->{message} || '';
205 my $fatal = $args->{fatal};
206 die "no triplets" unless defined( $args->{triplets} );
207 my @triplets;
208 if ( ref( $args->{triplets} ) eq 'ARRAY' ) {
209 @triplets = @{ $args->{triplets} };
210 } else {
211 @triplets = ( $args->{triplets} );
212 }
213
214 push @triplets, ( undef, undef ) if ( $#triplets == 0 );
215
216 die "wrapper doesn't have 3 elements but ", $#triplets unless (
217 ( $#triplets + 1 ) % 3 == 0
218 );
219
220 my ( $el, $attr, $value );
221
222 my @results;
223 my @tags;
224
225 while ( @triplets ) {
226 ( $el,$attr,$value ) = splice( @triplets, 0, 3 );
227 my $tag = $attr ? "<$el $attr=\"$value\">" : "<$el>";
228 push @tags, $tag;
229 $self->log->debug("looking for $message $tag");
230 @results = $tree->look_down( '_tag', $el, sub {
231 return 1 unless ( $attr && $value );
232 ( $_[0]->attr( $attr ) || '' ) eq $value;
233 });
234 last if @results;
235 }
236
237 if ( ! @results ) {
238 my $msg = "can't find $message ", join(" ", @tags);
239 die $msg if ( $fatal );
240 warn $msg;
241 return;
242 }
243
244 $self->log->debug("found ", $#results + 1, " results");
245
246 return @results if wantarray;
247 return shift @results;
248 }
249
250 sub scrape {
251 my $self = shift;
252
253 my $args = {@_};
254
255 $self->log->debug("scrape with args ",dump($args));
256
257 my ($feed,$uri,$q) = ($self->feed, $self->uri,$self->q);
258 die "no uri" unless ($uri);
259 die "feed is not a Grep::Model::Feed but ", ref $feed unless $feed->isa('Grep::Model::Feed');
260
261 sub mech_warn {
262 my $m = shift || return;
263 warn $m;
264 }
265
266 my $mech = WWW::Mechanize->new(
267 cookie_jar => {},
268 onwarn => \&mech_warn,
269 onerror => \&mech_warn,
270 );
271
272 $mech->get( $uri );
273
274 $self->save( 'get.html', $mech->content );
275
276 if ( my $form = $args->{submit_form} ) {
277 $self->log->debug("submit form on $uri with ", dump( $form ));
278 $mech->submit_form( %$form ) or die "can't submit form ", dump( $form );
279 $self->save( 'submit.html', $mech->content );
280 }
281
282 $self->log->debug("parse result page");
283
284 my $tree = HTML::TreeBuilder->new or die "can't create html tree";
285 $tree->parse( $mech->content ) or die "can't parse fetched content";
286
287 my $div = $self->element_by_triplet(
288 tree => $tree,
289 triplets => $args->{wrapper},
290 message => 'wrapper for all results',
291 fatal => 1
292 );
293
294 my $max = 15;
295 my $nr = 1;
296
297 my $base_uri = $uri;
298 $base_uri =~ s!\?.*$!!;
299
300 my @r = $self->element_by_triplet(
301 tree => $tree,
302 triplets => $args->{results},
303 message => 'result element',
304 );
305
306 foreach my $dt ( @r ) {
307 my $a = $dt->look_down( '_tag', 'a', sub { $_[0]->attr('href') } );
308 if ( $a ) {
309
310 my $href = $a->attr('href') or die "can't find href inside <", $args->{results}, ">";
311 my $page_uri = URI->new_abs( $a->attr('href'), $base_uri );
312 $page_uri->query( undef );
313 $page_uri = $page_uri->canonical;
314
315 $self->log->debug("fetching page: ",$a->as_text," from $page_uri");
316 if ( $mech->follow_link( url => $a->attr('href') ) ) {
317
318 $self->save( "page-${nr}.html", $mech->content );
319
320 my $page_tree = HTML::TreeBuilder->new or die "can't create page tree";
321 $page_tree->parse( $mech->content ) or die "can't parse page at $page_uri";
322 $div = $self->element_by_triplet(
323 tree => $page_tree,
324 message => "result $nr",
325 triplets => $args->{scrape}
326 );
327
328 $self->add_record(
329 in_feed => $feed,
330 title => $mech->title,
331 link => $page_uri,
332 content => $div->as_HTML,
333 # summary =>
334 # category =>
335 # author =>
336 # issued =>
337 # modified =>
338 ) if ( $div );
339
340 $mech->back;
341 $page_tree->delete;
342
343 } else {
344 warn "can't follow uri $page_uri: $!\n";
345 }
346 } else {
347 $self->log->debug("result $nr doesn't have link inside, ignoring...");
348 }
349
350 last if ($nr == $max);
351 $nr++;
352 }
353
354 $tree->delete; # clear memory!
355
356 }
357
358 =head2 save
359
360 save( 'name', $content );
361
362 Save dumps into C</tmp/grep> if writable
363
364 =cut
365
366 sub save {
367 my $self = shift;
368 my ( $file, $content ) = @_;
369 return unless ( defined($file) && defined($content) );
370 if ( -w '/tmp/grep' ) {
371 open(my $f, '>', "/tmp/grep/$file") or die "can't open $file: $!";
372 print $f $content or die "can't write to $file: $!";
373 close $f or die "can't close $file: $!";
374 $self->log->debug("saved $file ",length($content)," bytes");
375 }
376 }
377
378 1;

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