/[Grep]/lib/Grep/Source.pm
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Revision 132 - (hide annotations)
Tue May 1 12:20:49 2007 UTC (17 years, 1 month ago) by dpavlin
File size: 9736 byte(s)
Implemented redirect_single_result option for sources (MoinMoin uses that), and documented
element_by_triplet and scrape
1 dpavlin 72 # 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 dpavlin 100 use base qw(Class::Accessor Jifty::Object);
11 dpavlin 121 Grep::Source->mk_accessors( qw(feed uri q new_items collection search_obj tree) );
12 dpavlin 72
13 dpavlin 85 use HTML::TreeBuilder;
14     use WWW::Mechanize;
15     use XML::Feed;
16     use URI;
17 dpavlin 96 use HTML::ResolveLink;
18 dpavlin 85
19 dpavlin 72 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 dpavlin 73 Jifty->log->debug("Found source plugins: ", join(", ", __PACKAGE__->sources() ) );
38 dpavlin 72
39     =head2 new
40    
41     my $source = Grep::Source->new({ feed => $feed_record });
42    
43 dpavlin 73 This will also setup:
44    
45     =head2 feed
46    
47     isa L<Grep::Model::Feed>
48    
49 dpavlin 72 =head2 search
50    
51     my $collection = $source->search( 'query string' );
52    
53     It will also setup following accessors:
54    
55 dpavlin 73 =head2 q
56 dpavlin 72
57     Search query
58    
59 dpavlin 73 =head2 uri
60 dpavlin 72
61     URI of feed with embedded search query
62    
63 dpavlin 73 =head2 new_items
64 dpavlin 72
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 dpavlin 100 $self->log->info( $message );
105 dpavlin 72
106     $self->collection( Grep::Model::ItemCollection->new() );
107    
108 dpavlin 73 my $class = $self->feed->source || 'Grep::Source::Feed';
109 dpavlin 100 $self->log->debug("using $class");
110 dpavlin 72
111 dpavlin 110 $self->search_obj( Grep::Search->new() );
112     $self->log->debug("created " . $self->search_obj);
113 dpavlin 72
114 dpavlin 110 $class->fetch( $self );
115    
116     $self->search_obj->finish;
117    
118 dpavlin 72 return $self->collection;
119     }
120    
121     =head2 add_record
122    
123 dpavlin 73 Plugins will be called with parametar C<$parent> so they can call this method to add
124     record into result collection (and store in cache and index).
125    
126 dpavlin 72 $parent->add_record( id => 42, foo => 'bar', ... );
127    
128 dpavlin 73 This will also update L</new_items>
129    
130 dpavlin 72 =cut
131    
132     sub add_record {
133     my $self = shift;
134    
135 dpavlin 110 $self->log->confess("no search_obj") unless ($self->search_obj);
136 dpavlin 109
137 dpavlin 72 my $i = Grep::Model::Item->new();
138    
139 dpavlin 96 my $rec = {@_};
140 dpavlin 72
141 dpavlin 102 $self->log->debug("resolving links using base ", $rec->{link});
142 dpavlin 96 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 dpavlin 72 $msg ||= '';
148    
149     if ( $ok ) {
150 dpavlin 100 $self->log->debug("item ", $i->id, ": $msg");
151 dpavlin 72 $self->collection->add_record( $i );
152    
153     # is new record?
154     if ( $msg !~ m/^Found/ ) {
155 dpavlin 110 $self->search_obj->add( $i );
156 dpavlin 74 $self->new_items( ( $self->new_items || 0 ) + 1 );
157 dpavlin 72 }
158     } else {
159     warn "can't add entry ", dump( @_ ), "\n";
160     }
161     }
162    
163 dpavlin 73 =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 dpavlin 100 $self->log->debug("testing source class $s");
178 dpavlin 82 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 dpavlin 100 $self->log->debug("${s}->content_have succesful");
185 dpavlin 82 return $s;
186     }
187 dpavlin 73 }
188     }
189     }
190    
191 dpavlin 85
192 dpavlin 132 =head2 element_by_triplet
193 dpavlin 85
194 dpavlin 132 Helper method to select element(s) using C<element/attribute/value> triplet using
195     L<HTML::TreeBuilder> trees.
196 dpavlin 85
197 dpavlin 132 my $el = $self->element_by_triplet(
198     tree => $tree_or_element,
199     triplets => [ qw/
200     div id target
201     div class another
202     / ],
203     message => 'find search result element',
204     fatal => 1, # die instead of warn
205     );
206    
207 dpavlin 85 =cut
208    
209 dpavlin 121 sub element_by_triplet {
210     my $self = shift;
211    
212     my $args = {@_};
213    
214     my $tree = $args->{tree} || die "no tree";
215 dpavlin 123 my $message = $args->{message} || '';
216 dpavlin 121 my $fatal = $args->{fatal};
217 dpavlin 126 die "no triplets" unless defined( $args->{triplets} );
218     my @triplets;
219     if ( ref( $args->{triplets} ) eq 'ARRAY' ) {
220     @triplets = @{ $args->{triplets} };
221 dpavlin 123 } else {
222 dpavlin 126 @triplets = ( $args->{triplets} );
223 dpavlin 123 }
224 dpavlin 121
225 dpavlin 126 push @triplets, ( undef, undef ) if ( $#triplets == 0 );
226 dpavlin 121
227 dpavlin 132 die "triplet doesn't have 3 elements but ", $#triplets unless (
228 dpavlin 126 ( $#triplets + 1 ) % 3 == 0
229 dpavlin 121 );
230    
231 dpavlin 123 my ( $el, $attr, $value );
232 dpavlin 121
233 dpavlin 123 my @results;
234 dpavlin 121 my @tags;
235    
236 dpavlin 126 while ( @triplets ) {
237     ( $el,$attr,$value ) = splice( @triplets, 0, 3 );
238 dpavlin 121 my $tag = $attr ? "<$el $attr=\"$value\">" : "<$el>";
239     push @tags, $tag;
240     $self->log->debug("looking for $message $tag");
241 dpavlin 123 @results = $tree->look_down( '_tag', $el, sub {
242 dpavlin 121 return 1 unless ( $attr && $value );
243     ( $_[0]->attr( $attr ) || '' ) eq $value;
244     });
245 dpavlin 123 last if @results;
246 dpavlin 121 }
247    
248 dpavlin 123 if ( ! @results ) {
249 dpavlin 121 my $msg = "can't find $message ", join(" ", @tags);
250     die $msg if ( $fatal );
251     warn $msg;
252     return;
253     }
254    
255 dpavlin 123 $self->log->debug("found ", $#results + 1, " results");
256    
257     return @results if wantarray;
258     return shift @results;
259 dpavlin 121 }
260    
261 dpavlin 132 =head2 scrape
262    
263     Create semi-complex L<WWW::Mechanize> rules to scrape page easily
264    
265     $parent->scrape(
266     # if search string isn't part or URI
267     submit_form => {
268     fields => {
269     value => $parent->q,
270     },
271     button => 'fullsearch',
272     },
273     # element with search results
274     wrapper => [ qw/div class searchresults/ ],
275     # element (or tripple) for each result with link
276     # <a href=".."> inside it to full-text result
277     results => 'dt',
278     # collect which element on page linked from results
279     scrape => [ qw/div id page/ ],
280     # when search returns just single hit, it will redirect to result page
281     redirect_single_result => 1,
282     );
283    
284     =cut
285    
286 dpavlin 85 sub scrape {
287     my $self = shift;
288    
289     my $args = {@_};
290    
291 dpavlin 102 $self->log->debug("scrape with args ",dump($args));
292 dpavlin 85
293     my ($feed,$uri,$q) = ($self->feed, $self->uri,$self->q);
294     die "no uri" unless ($uri);
295     die "feed is not a Grep::Model::Feed but ", ref $feed unless $feed->isa('Grep::Model::Feed');
296    
297 dpavlin 92 sub mech_warn {
298     my $m = shift || return;
299     warn $m;
300     }
301 dpavlin 85
302 dpavlin 92 my $mech = WWW::Mechanize->new(
303     cookie_jar => {},
304     onwarn => \&mech_warn,
305     onerror => \&mech_warn,
306     );
307    
308 dpavlin 85 $mech->get( $uri );
309    
310 dpavlin 86 $self->save( 'get.html', $mech->content );
311 dpavlin 85
312 dpavlin 92 if ( my $form = $args->{submit_form} ) {
313 dpavlin 102 $self->log->debug("submit form on $uri with ", dump( $form ));
314 dpavlin 92 $mech->submit_form( %$form ) or die "can't submit form ", dump( $form );
315 dpavlin 86 $self->save( 'submit.html', $mech->content );
316 dpavlin 85 }
317    
318 dpavlin 102 $self->log->debug("parse result page");
319 dpavlin 85
320     my $tree = HTML::TreeBuilder->new or die "can't create html tree";
321     $tree->parse( $mech->content ) or die "can't parse fetched content";
322    
323 dpavlin 121 my $div = $self->element_by_triplet(
324     tree => $tree,
325 dpavlin 126 triplets => $args->{wrapper},
326 dpavlin 121 message => 'wrapper for all results',
327 dpavlin 132 fatal => $args->{redirect_single_result} ? 0 : 1,
328 dpavlin 121 );
329 dpavlin 85
330 dpavlin 103 my $max = 15;
331 dpavlin 85 my $nr = 1;
332    
333     my $base_uri = $uri;
334     $base_uri =~ s!\?.*$!!;
335    
336 dpavlin 132 # directly got first result
337     if ( $args->{redirect_single_result} && ! $div ) {
338    
339     my $uri = $mech->uri; $uri->query( undef ); $uri = $uri->canonical;
340    
341     $div = $self->element_by_triplet(
342     tree => $tree,
343     message => "single result - redirect to $uri",
344     triplets => $args->{scrape},
345     fatal => 1,
346     );
347    
348     $self->add_record(
349     in_feed => $feed,
350     title => $mech->title,
351     link => $uri,
352     content => $div->as_HTML,
353     );
354    
355     $tree->delete; # clear memory!
356     return;
357     }
358    
359 dpavlin 121 my @r = $self->element_by_triplet(
360 dpavlin 132 tree => $div,
361 dpavlin 126 triplets => $args->{results},
362 dpavlin 121 message => 'result element',
363     );
364 dpavlin 113
365     foreach my $dt ( @r ) {
366 dpavlin 85 my $a = $dt->look_down( '_tag', 'a', sub { $_[0]->attr('href') } );
367     if ( $a ) {
368    
369     my $href = $a->attr('href') or die "can't find href inside <", $args->{results}, ">";
370 dpavlin 132
371     my $page_uri = URI->new_abs( $href, $base_uri );
372 dpavlin 85 $page_uri->query( undef );
373     $page_uri = $page_uri->canonical;
374    
375 dpavlin 102 $self->log->debug("fetching page: ",$a->as_text," from $page_uri");
376 dpavlin 132 if ( $mech->follow_link( url => $href ) ) {
377 dpavlin 85
378 dpavlin 86 $self->save( "page-${nr}.html", $mech->content );
379 dpavlin 85
380     my $page_tree = HTML::TreeBuilder->new or die "can't create page tree";
381     $page_tree->parse( $mech->content ) or die "can't parse page at $page_uri";
382 dpavlin 121 $div = $self->element_by_triplet(
383     tree => $page_tree,
384     message => "result $nr",
385 dpavlin 126 triplets => $args->{scrape}
386 dpavlin 121 );
387 dpavlin 85
388     $self->add_record(
389     in_feed => $feed,
390     title => $mech->title,
391     link => $page_uri,
392     content => $div->as_HTML,
393     # summary =>
394     # category =>
395     # author =>
396     # issued =>
397     # modified =>
398 dpavlin 121 ) if ( $div );
399 dpavlin 85
400     $mech->back;
401     $page_tree->delete;
402    
403     } else {
404     warn "can't follow uri $page_uri: $!\n";
405     }
406 dpavlin 121 } else {
407     $self->log->debug("result $nr doesn't have link inside, ignoring...");
408 dpavlin 85 }
409    
410     last if ($nr == $max);
411     $nr++;
412     }
413    
414     $tree->delete; # clear memory!
415    
416     }
417    
418 dpavlin 86 =head2 save
419    
420     save( 'name', $content );
421    
422     Save dumps into C</tmp/grep> if writable
423    
424     =cut
425    
426     sub save {
427     my $self = shift;
428     my ( $file, $content ) = @_;
429 dpavlin 100 return unless ( defined($file) && defined($content) );
430 dpavlin 86 if ( -w '/tmp/grep' ) {
431     open(my $f, '>', "/tmp/grep/$file") or die "can't open $file: $!";
432     print $f $content or die "can't write to $file: $!";
433     close $f or die "can't close $file: $!";
434 dpavlin 100 $self->log->debug("saved $file ",length($content)," bytes");
435 dpavlin 86 }
436     }
437    
438 dpavlin 72 1;

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