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51bec050 |
1 | package DBIx::Class::FilterColumn; |
51bec050 |
2 | use strict; |
3 | use warnings; |
4 | |
5 | use base qw/DBIx::Class::Row/; |
6 | |
7 | sub filter_column { |
8 | my ($self, $col, $attrs) = @_; |
9 | |
eec182b6 |
10 | $self->throw_exception('FilterColumn does not work with InflateColumn') |
c227b295 |
11 | if $self->isa('DBIx::Class::InflateColumn') && |
12 | defined $self->column_info($col)->{_inflate_info}; |
13 | |
51bec050 |
14 | $self->throw_exception("No such column $col to filter") |
15 | unless $self->has_column($col); |
16 | |
eec182b6 |
17 | $self->throw_exception('filter_column expects a hashref of filter specifications') |
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18 | unless ref $attrs eq 'HASH'; |
19 | |
eec182b6 |
20 | $self->throw_exception('An invocation of filter_column() must specify either a filter_from_storage or filter_to_storage') |
21 | unless $attrs->{filter_from_storage} || $attrs->{filter_to_storage}; |
22 | |
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23 | $self->column_info($col)->{_filter_info} = $attrs; |
24 | my $acc = $self->column_info($col)->{accessor}; |
d7d38bef |
25 | $self->mk_group_accessors(filtered_column => [ (defined $acc ? $acc : $col), $col]); |
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26 | return 1; |
27 | } |
28 | |
4c0c3038 |
29 | sub _column_from_storage { |
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30 | my ($self, $col, $value) = @_; |
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31 | |
32 | return $value unless defined $value; |
33 | |
34 | my $info = $self->column_info($col) |
35 | or $self->throw_exception("No column info for $col"); |
36 | |
37 | return $value unless exists $info->{_filter_info}; |
38 | |
d7d38bef |
39 | my $filter = $info->{_filter_info}{filter_from_storage}; |
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40 | |
eec182b6 |
41 | return defined $filter ? $self->$filter($value) : $value; |
51bec050 |
42 | } |
43 | |
4c0c3038 |
44 | sub _column_to_storage { |
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45 | my ($self, $col, $value) = @_; |
51bec050 |
46 | |
47 | my $info = $self->column_info($col) or |
48 | $self->throw_exception("No column info for $col"); |
49 | |
50 | return $value unless exists $info->{_filter_info}; |
51 | |
d7d38bef |
52 | my $unfilter = $info->{_filter_info}{filter_to_storage}; |
eec182b6 |
53 | |
54 | return defined $unfilter ? $self->$unfilter($value) : $value; |
51bec050 |
55 | } |
56 | |
d7d38bef |
57 | sub get_filtered_column { |
51bec050 |
58 | my ($self, $col) = @_; |
59 | |
60 | $self->throw_exception("$col is not a filtered column") |
61 | unless exists $self->column_info($col)->{_filter_info}; |
62 | |
63 | return $self->{_filtered_column}{$col} |
64 | if exists $self->{_filtered_column}{$col}; |
65 | |
66 | my $val = $self->get_column($col); |
67 | |
9b2c0de6 |
68 | return $self->{_filtered_column}{$col} = $self->_column_from_storage($col, $val); |
51bec050 |
69 | } |
70 | |
491c8ff9 |
71 | sub get_column { |
72 | my ($self, $col) = @_; |
73 | if (exists $self->{_filtered_column}{$col}) { |
74 | return $self->{_column_data}{$col} ||= $self->_column_to_storage ($col, $self->{_filtered_column}{$col}); |
75 | } |
76 | |
77 | return $self->next::method ($col); |
78 | } |
79 | |
80 | # sadly a separate codepath in Row.pm ( used by insert() ) |
81 | sub get_columns { |
82 | my $self = shift; |
83 | |
84 | foreach my $col (keys %{$self->{_filtered_column}||{}}) { |
85 | $self->{_column_data}{$col} ||= $self->_column_to_storage ($col, $self->{_filtered_column}{$col}) |
86 | if exists $self->{_filtered_column}{$col}; |
87 | } |
88 | |
89 | $self->next::method (@_); |
90 | } |
91 | |
92 | sub store_column { |
85439e0c |
93 | my ($self, $col) = (shift, @_); |
94 | |
95 | # blow cache |
96 | delete $self->{_filtered_column}{$col}; |
97 | |
98 | $self->next::method(@_); |
99 | } |
100 | |
d7d38bef |
101 | sub set_filtered_column { |
51bec050 |
102 | my ($self, $col, $filtered) = @_; |
103 | |
cde96798 |
104 | # do not blow up the cache via set_column unless necessary |
105 | # (filtering may be expensive!) |
106 | if (exists $self->{_filtered_column}{$col}) { |
107 | return $filtered |
108 | if ($self->_eq_column_values ($col, $filtered, $self->{_filtered_column}{$col} ) ); |
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109 | |
cde96798 |
110 | $self->make_column_dirty ($col); # so the comparison won't run again |
111 | } |
112 | |
113 | $self->set_column($col, $self->_column_to_storage($col, $filtered)); |
51bec050 |
114 | |
491c8ff9 |
115 | return $self->{_filtered_column}{$col} = $filtered; |
51bec050 |
116 | } |
117 | |
7b461f8a |
118 | sub update { |
119 | my ($self, $attrs, @rest) = @_; |
491c8ff9 |
120 | |
7b461f8a |
121 | foreach my $key (keys %{$attrs||{}}) { |
491c8ff9 |
122 | if ( |
123 | $self->has_column($key) |
124 | && |
125 | exists $self->column_info($key)->{_filter_info} |
126 | ) { |
127 | $self->set_filtered_column($key, delete $attrs->{$key}); |
7c6fa77f |
128 | |
129 | # FIXME update() reaches directly into the object-hash |
130 | # and we may *not* have a filtered value there - thus |
131 | # the void-ctx filter-trigger |
132 | $self->get_column($key) unless exists $self->{_column_data}{$key}; |
7b461f8a |
133 | } |
134 | } |
491c8ff9 |
135 | |
7b461f8a |
136 | return $self->next::method($attrs, @rest); |
137 | } |
138 | |
7b461f8a |
139 | sub new { |
140 | my ($class, $attrs, @rest) = @_; |
9b2c0de6 |
141 | my $source = $attrs->{-result_source} |
d9ea6d6d |
142 | or $class->throw_exception('Sourceless rows are not supported with DBIx::Class::FilterColumn'); |
143 | |
9b2c0de6 |
144 | my $obj = $class->next::method($attrs, @rest); |
7b461f8a |
145 | foreach my $key (keys %{$attrs||{}}) { |
9b2c0de6 |
146 | if ($obj->has_column($key) && |
147 | exists $obj->column_info($key)->{_filter_info} ) { |
491c8ff9 |
148 | $obj->set_filtered_column($key, $attrs->{$key}); |
7b461f8a |
149 | } |
150 | } |
491c8ff9 |
151 | |
7b461f8a |
152 | return $obj; |
153 | } |
154 | |
51bec050 |
155 | 1; |
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156 | |
9b2c0de6 |
157 | =head1 NAME |
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158 | |
9b2c0de6 |
159 | DBIx::Class::FilterColumn - Automatically convert column data |
160 | |
161 | =head1 SYNOPSIS |
162 | |
f10a2e9a |
163 | In your Schema or DB class add "FilterColumn" to the top of the component list. |
164 | |
165 | __PACKAGE__->load_components(qw( FilterColumn ... )); |
166 | |
167 | Set up filters for the columns you want to convert. |
168 | |
9b2c0de6 |
169 | __PACKAGE__->filter_column( money => { |
170 | filter_to_storage => 'to_pennies', |
171 | filter_from_storage => 'from_pennies', |
172 | }); |
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173 | |
174 | sub to_pennies { $_[1] * 100 } |
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175 | |
22d9e05a |
176 | sub from_pennies { $_[1] / 100 } |
177 | |
178 | 1; |
179 | |
f10a2e9a |
180 | |
9b2c0de6 |
181 | =head1 DESCRIPTION |
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182 | |
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183 | This component is meant to be a more powerful, but less DWIM-y, |
184 | L<DBIx::Class::InflateColumn>. One of the major issues with said component is |
185 | that it B<only> works with references. Generally speaking anything that can |
186 | be done with L<DBIx::Class::InflateColumn> can be done with this component. |
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187 | |
9b2c0de6 |
188 | =head1 METHODS |
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189 | |
9b2c0de6 |
190 | =head2 filter_column |
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191 | |
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192 | __PACKAGE__->filter_column( colname => { |
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193 | filter_from_storage => 'method'|\&coderef, |
194 | filter_to_storage => 'method'|\&coderef, |
9b2c0de6 |
195 | }) |
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196 | |
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197 | This is the method that you need to call to set up a filtered column. It takes |
198 | exactly two arguments; the first being the column name the second being a hash |
199 | reference with C<filter_from_storage> and C<filter_to_storage> set to either |
200 | a method name or a code reference. In either case the filter is invoked as: |
201 | |
202 | $row_obj->$filter_specification ($value_to_filter) |
203 | |
204 | with C<$filter_specification> being chosen depending on whether the |
205 | C<$value_to_filter> is being retrieved from or written to permanent |
206 | storage. |
207 | |
208 | If a specific directional filter is not specified, the original value will be |
209 | passed to/from storage unfiltered. |
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210 | |
9b2c0de6 |
211 | =head2 get_filtered_column |
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212 | |
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213 | $obj->get_filtered_column('colname') |
214 | |
215 | Returns the filtered value of the column |
216 | |
217 | =head2 set_filtered_column |
218 | |
219 | $obj->set_filtered_column(colname => 'new_value') |
220 | |
221 | Sets the filtered value of the column |
eec182b6 |
222 | |
223 | =head1 EXAMPLE OF USE |
224 | |
225 | Some databases have restrictions on values that can be passed to |
226 | boolean columns, and problems can be caused by passing value that |
227 | perl considers to be false (such as C<undef>). |
228 | |
229 | One solution to this is to ensure that the boolean values are set |
230 | to something that the database can handle - such as numeric zero |
231 | and one, using code like this:- |
232 | |
233 | __PACKAGE__->filter_column( |
234 | my_boolean_column => { |
235 | filter_to_storage => sub { $_[1] ? 1 : 0 }, |
236 | } |
237 | ); |
238 | |
239 | In this case the C<filter_from_storage> is not required, as just |
240 | passing the database value through to perl does the right thing. |