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89c0a5a2 |
1 | package DBIx::Class::ResultSet; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | use overload |
6 | '0+' => 'count', |
7 | fallback => 1; |
3c5b25c5 |
8 | use Data::Page; |
89c0a5a2 |
9 | |
ee38fa40 |
10 | =head1 NAME |
11 | |
12 | DBIX::Class::Recordset - Responsible for fetching and creating recordsets. |
13 | |
14 | =head1 SYNOPSIS; |
15 | |
16 | $rs=MyApp::DB::Class->search(registered=>1); |
17 | |
18 | =head1 DESCRIPTION |
19 | |
20 | The recordset is also know as an iterator. |
21 | |
22 | =head1 METHODS |
23 | |
24 | =over 4 |
25 | |
26 | =item new <db_class> <attrs> |
27 | |
28 | The recordset constructor. Takes a db class and an |
29 | attribute hash (see below for more info on attributes) |
30 | |
31 | =cut |
32 | |
89c0a5a2 |
33 | sub new { |
7624b19f |
34 | my ($it_class, $db_class, $attrs) = @_; |
89c0a5a2 |
35 | #use Data::Dumper; warn Dumper(@_); |
36 | $it_class = ref $it_class if ref $it_class; |
37 | $attrs = { %{ $attrs || {} } }; |
c7ce65e6 |
38 | my %seen; |
39 | $attrs->{cols} ||= [ map { "me.$_" } $db_class->_select_columns ]; |
40 | $attrs->{from} ||= [ { 'me' => $db_class->_table_name } ]; |
fef5d100 |
41 | if ($attrs->{join}) { |
c7ce65e6 |
42 | foreach my $j (ref $attrs->{join} eq 'ARRAY' |
43 | ? (@{$attrs->{join}}) : ($attrs->{join})) { |
44 | if (ref $j eq 'HASH') { |
45 | $seen{$_} = 1 foreach keys %$j; |
46 | } else { |
47 | $seen{$j} = 1; |
48 | } |
49 | } |
50 | push(@{$attrs->{from}}, $db_class->_resolve_join($attrs->{join}, 'me')); |
51 | } |
52 | foreach my $pre (@{$attrs->{prefetch} || []}) { |
53 | push(@{$attrs->{from}}, $db_class->_resolve_join($pre, 'me')) |
54 | unless $seen{$pre}; |
55 | push(@{$attrs->{cols}}, |
56 | map { "$pre.$_" } |
ddab752c |
57 | $db_class->_relationships->{$pre}->{class}->_select_columns); |
fef5d100 |
58 | } |
89c0a5a2 |
59 | my $new = { |
60 | class => $db_class, |
fef5d100 |
61 | cols => $attrs->{cols} || [ $db_class->_select_columns ], |
89c0a5a2 |
62 | cond => $attrs->{where}, |
fef5d100 |
63 | from => $attrs->{from} || $db_class->_table_name, |
3c5b25c5 |
64 | count => undef, |
65 | pager => undef, |
89c0a5a2 |
66 | attrs => $attrs }; |
9229f20a |
67 | bless ($new, $it_class); |
68 | $new->pager if ($attrs->{page}); |
69 | return $new; |
89c0a5a2 |
70 | } |
71 | |
ee38fa40 |
72 | =item cursor |
73 | |
74 | Return a storage driven cursor to the given record set. |
75 | |
76 | =cut |
77 | |
73f58123 |
78 | sub cursor { |
79 | my ($self) = @_; |
80 | my ($db_class, $attrs) = @{$self}{qw/class attrs/}; |
3c5b25c5 |
81 | if ($attrs->{page}) { |
82 | $attrs->{rows} = $self->pager->entries_per_page; |
83 | $attrs->{offset} = $self->pager->skipped; |
84 | } |
73f58123 |
85 | return $self->{cursor} |
fef5d100 |
86 | ||= $db_class->storage->select($self->{from}, $self->{cols}, |
73f58123 |
87 | $attrs->{where},$attrs); |
88 | } |
89 | |
ee38fa40 |
90 | =item slice <first> <last> |
91 | |
92 | return a number of elements from the given record set. |
93 | |
94 | =cut |
95 | |
89c0a5a2 |
96 | sub slice { |
97 | my ($self, $min, $max) = @_; |
98 | my $attrs = { %{ $self->{attrs} || {} } }; |
99 | $self->{class}->throw("Can't slice without where") unless $attrs->{where}; |
100 | $attrs->{offset} = $min; |
101 | $attrs->{rows} = ($max ? ($max - $min + 1) : 1); |
7624b19f |
102 | my $slice = $self->new($self->{class}, $attrs); |
89c0a5a2 |
103 | return (wantarray ? $slice->all : $slice); |
104 | } |
105 | |
ee38fa40 |
106 | =item next |
107 | |
108 | Returns the next element in this record set. |
109 | |
110 | =cut |
111 | |
89c0a5a2 |
112 | sub next { |
113 | my ($self) = @_; |
73f58123 |
114 | my @row = $self->cursor->next; |
89c0a5a2 |
115 | return unless (@row); |
c7ce65e6 |
116 | return $self->_construct_object(@row); |
117 | } |
118 | |
119 | sub _construct_object { |
120 | my ($self, @row) = @_; |
121 | my @cols = $self->{class}->_select_columns; |
33ce49d6 |
122 | my $new; |
c7ce65e6 |
123 | unless ($self->{attrs}{prefetch}) { |
33ce49d6 |
124 | $new = $self->{class}->_row_to_object(\@cols, \@row); |
c7ce65e6 |
125 | } else { |
126 | my @main = splice(@row, 0, scalar @cols); |
33ce49d6 |
127 | $new = $self->{class}->_row_to_object(\@cols, \@main); |
c7ce65e6 |
128 | PRE: foreach my $pre (@{$self->{attrs}{prefetch}}) { |
129 | my $rel_obj = $self->{class}->_relationships->{$pre}; |
dd417d06 |
130 | my $pre_class = $self->{class}->resolve_class($rel_obj->{class}); |
131 | my @pre_cols = $pre_class->_select_columns; |
c7ce65e6 |
132 | my @vals = splice(@row, 0, scalar @pre_cols); |
dd417d06 |
133 | my $fetched = $pre_class->_row_to_object(\@pre_cols, \@vals); |
c7ce65e6 |
134 | $self->{class}->throw("No accessor for prefetched $pre") |
135 | unless defined $rel_obj->{attrs}{accessor}; |
136 | if ($rel_obj->{attrs}{accessor} eq 'single') { |
137 | foreach my $pri ($rel_obj->{class}->primary_columns) { |
7cd300ea |
138 | unless (defined $fetched->get_column($pri)) { |
139 | undef $fetched; |
140 | last; |
141 | } |
c7ce65e6 |
142 | } |
143 | $new->{_relationship_data}{$pre} = $fetched; |
144 | } elsif ($rel_obj->{attrs}{accessor} eq 'filter') { |
145 | $new->{_inflated_column}{$pre} = $fetched; |
146 | } else { |
3125eb1f |
147 | $self->{class}->throw("Don't know how to store prefetched $pre"); |
c7ce65e6 |
148 | } |
149 | } |
c7ce65e6 |
150 | } |
33ce49d6 |
151 | $new = $self->{attrs}{record_filter}->($new) |
152 | if exists $self->{attrs}{record_filter}; |
153 | return $new; |
89c0a5a2 |
154 | } |
155 | |
ee38fa40 |
156 | =item count |
157 | |
158 | Performs an SQL count with the same query as the resultset was built |
159 | with to find the number of elements. |
160 | |
161 | =cut |
162 | |
163 | |
89c0a5a2 |
164 | sub count { |
165 | my ($self) = @_; |
7624b19f |
166 | my $db_class = $self->{class}; |
59f8e584 |
167 | my $attrs = { %{ $self->{attrs} } }; |
3c5b25c5 |
168 | unless ($self->{count}) { |
169 | # offset and order by are not needed to count |
170 | delete $attrs->{$_} for qw/offset order_by/; |
171 | |
172 | my @cols = 'COUNT(*)'; |
fef5d100 |
173 | $self->{count} = $db_class->storage->select_single($self->{from}, \@cols, |
3c5b25c5 |
174 | $self->{cond}, $attrs); |
175 | } |
176 | return 0 unless $self->{count}; |
9229f20a |
177 | return $self->{pager}->entries_on_this_page if ($self->{pager}); |
3c5b25c5 |
178 | return ( $attrs->{rows} && $attrs->{rows} < $self->{count} ) |
59f8e584 |
179 | ? $attrs->{rows} |
3c5b25c5 |
180 | : $self->{count}; |
89c0a5a2 |
181 | } |
182 | |
ee38fa40 |
183 | =item all |
184 | |
185 | Returns all elements in the recordset. Is called implictly if the search |
186 | method is used in list context. |
187 | |
188 | =cut |
189 | |
89c0a5a2 |
190 | sub all { |
191 | my ($self) = @_; |
c7ce65e6 |
192 | return map { $self->_construct_object(@$_); } |
73f58123 |
193 | $self->cursor->all; |
89c0a5a2 |
194 | } |
195 | |
ee38fa40 |
196 | =item reset |
197 | |
198 | Reset this recordset's cursor, so you can iterate through the elements again. |
199 | |
200 | =cut |
201 | |
89c0a5a2 |
202 | sub reset { |
203 | my ($self) = @_; |
73f58123 |
204 | $self->cursor->reset; |
89c0a5a2 |
205 | return $self; |
206 | } |
207 | |
ee38fa40 |
208 | =item first |
209 | |
210 | resets the recordset and returns the first element. |
211 | |
212 | =cut |
213 | |
89c0a5a2 |
214 | sub first { |
215 | return $_[0]->reset->next; |
216 | } |
217 | |
ee38fa40 |
218 | =item delete |
219 | |
220 | Deletes all elements in the recordset. |
221 | |
222 | =cut |
223 | |
28927b50 |
224 | sub delete { |
89c0a5a2 |
225 | my ($self) = @_; |
226 | $_->delete for $self->all; |
227 | return 1; |
228 | } |
229 | |
28927b50 |
230 | *delete_all = \&delete; # Yeah, yeah, yeah ... |
231 | |
ee38fa40 |
232 | =item pager |
233 | |
234 | Returns a L<Data::Page> object for the current resultset. Only makes |
235 | sense for queries with page turned on. |
236 | |
237 | =cut |
238 | |
3c5b25c5 |
239 | sub pager { |
240 | my ($self) = @_; |
241 | my $attrs = $self->{attrs}; |
242 | delete $attrs->{offset}; |
243 | my $rows_per_page = delete $attrs->{rows} || 10; |
244 | $self->{pager} ||= Data::Page->new( |
245 | $self->count, $rows_per_page, $attrs->{page} || 1); |
246 | $attrs->{rows} = $rows_per_page; |
247 | return $self->{pager}; |
248 | } |
249 | |
ee38fa40 |
250 | =item page <page> |
251 | |
252 | Returns a new recordset representing a given page. |
253 | |
254 | =cut |
255 | |
3c5b25c5 |
256 | sub page { |
257 | my ($self, $page) = @_; |
258 | my $attrs = $self->{attrs}; |
259 | $attrs->{page} = $page; |
260 | return $self->new($self->{class}, $attrs); |
261 | } |
262 | |
ee38fa40 |
263 | =back |
076652e8 |
264 | |
265 | =head1 Attributes |
266 | |
267 | The recordset is responsible for handling the various attributes that |
268 | can be passed in with the search functions. Here's an overview of them: |
269 | |
270 | =over 4 |
271 | |
272 | =item order_by |
273 | |
274 | Which column to order the results by. |
ee38fa40 |
275 | |
276 | =item cols |
277 | |
278 | Which cols should be retrieved on the first search. |
279 | |
280 | =item join |
281 | |
282 | Contains a list of relations that should be joined for this query. Can also |
283 | contain a hash referece to refer to that relation's relations. |
284 | |
285 | =item from |
286 | |
287 | This attribute can contain a arrayref of elements. each element can be another |
288 | arrayref, to nest joins, or it can be a hash which represents the two sides |
289 | of the join. |
290 | |
291 | *NOTE* Use this on your own risk. This allows you to shoot your foot off! |
292 | |
076652e8 |
293 | =item page |
294 | |
295 | Should the resultset be paged? This can also be enabled by using the |
296 | 'page' option. |
297 | |
298 | =item rows |
299 | |
300 | For paged resultsset, how many rows per page |
301 | |
302 | =item offset |
303 | |
304 | For paged resultsset, which page to start on. |
305 | |
306 | =back |
307 | |
89c0a5a2 |
308 | 1; |