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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 | |
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10 | my $colinfo = $self->column_info($col); |
11 | |
85aee309 |
12 | $self->throw_exception("FilterColumn can not be used on a column with a declared InflateColumn inflator") |
13 | if defined $colinfo->{_inflate_info} and $self->isa('DBIx::Class::InflateColumn'); |
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14 | |
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15 | $self->throw_exception("No such column $col to filter") |
16 | unless $self->has_column($col); |
17 | |
eec182b6 |
18 | $self->throw_exception('filter_column expects a hashref of filter specifications') |
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19 | unless ref $attrs eq 'HASH'; |
20 | |
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21 | $self->throw_exception('An invocation of filter_column() must specify either a filter_from_storage or filter_to_storage') |
22 | unless $attrs->{filter_from_storage} || $attrs->{filter_to_storage}; |
23 | |
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24 | $colinfo->{_filter_info} = $attrs; |
25 | my $acc = $colinfo->{accessor}; |
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26 | $self->mk_group_accessors(filtered_column => [ (defined $acc ? $acc : $col), $col]); |
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27 | return 1; |
28 | } |
29 | |
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30 | sub _column_from_storage { |
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31 | my ($self, $col, $value) = @_; |
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32 | |
33 | return $value unless defined $value; |
34 | |
35 | my $info = $self->column_info($col) |
36 | or $self->throw_exception("No column info for $col"); |
37 | |
38 | return $value unless exists $info->{_filter_info}; |
39 | |
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40 | my $filter = $info->{_filter_info}{filter_from_storage}; |
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41 | |
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42 | return defined $filter ? $self->$filter($value) : $value; |
51bec050 |
43 | } |
44 | |
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45 | sub _column_to_storage { |
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46 | my ($self, $col, $value) = @_; |
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47 | |
48 | my $info = $self->column_info($col) or |
49 | $self->throw_exception("No column info for $col"); |
50 | |
51 | return $value unless exists $info->{_filter_info}; |
52 | |
d7d38bef |
53 | my $unfilter = $info->{_filter_info}{filter_to_storage}; |
eec182b6 |
54 | |
55 | return defined $unfilter ? $self->$unfilter($value) : $value; |
51bec050 |
56 | } |
57 | |
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58 | sub get_filtered_column { |
51bec050 |
59 | my ($self, $col) = @_; |
60 | |
61 | $self->throw_exception("$col is not a filtered column") |
62 | unless exists $self->column_info($col)->{_filter_info}; |
63 | |
64 | return $self->{_filtered_column}{$col} |
65 | if exists $self->{_filtered_column}{$col}; |
66 | |
67 | my $val = $self->get_column($col); |
68 | |
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69 | return $self->{_filtered_column}{$col} = $self->_column_from_storage($col, $val); |
51bec050 |
70 | } |
71 | |
491c8ff9 |
72 | sub get_column { |
73 | my ($self, $col) = @_; |
74 | if (exists $self->{_filtered_column}{$col}) { |
75 | return $self->{_column_data}{$col} ||= $self->_column_to_storage ($col, $self->{_filtered_column}{$col}); |
76 | } |
77 | |
78 | return $self->next::method ($col); |
79 | } |
80 | |
81 | # sadly a separate codepath in Row.pm ( used by insert() ) |
82 | sub get_columns { |
83 | my $self = shift; |
84 | |
85 | foreach my $col (keys %{$self->{_filtered_column}||{}}) { |
86 | $self->{_column_data}{$col} ||= $self->_column_to_storage ($col, $self->{_filtered_column}{$col}) |
87 | if exists $self->{_filtered_column}{$col}; |
88 | } |
89 | |
90 | $self->next::method (@_); |
91 | } |
92 | |
93 | sub store_column { |
85439e0c |
94 | my ($self, $col) = (shift, @_); |
95 | |
96 | # blow cache |
97 | delete $self->{_filtered_column}{$col}; |
98 | |
99 | $self->next::method(@_); |
100 | } |
101 | |
d7d38bef |
102 | sub set_filtered_column { |
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103 | my ($self, $col, $filtered) = @_; |
104 | |
cde96798 |
105 | # do not blow up the cache via set_column unless necessary |
106 | # (filtering may be expensive!) |
107 | if (exists $self->{_filtered_column}{$col}) { |
108 | return $filtered |
109 | if ($self->_eq_column_values ($col, $filtered, $self->{_filtered_column}{$col} ) ); |
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110 | |
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111 | $self->make_column_dirty ($col); # so the comparison won't run again |
112 | } |
113 | |
114 | $self->set_column($col, $self->_column_to_storage($col, $filtered)); |
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115 | |
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116 | return $self->{_filtered_column}{$col} = $filtered; |
51bec050 |
117 | } |
118 | |
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119 | sub update { |
120 | my ($self, $attrs, @rest) = @_; |
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121 | |
7b461f8a |
122 | foreach my $key (keys %{$attrs||{}}) { |
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123 | if ( |
124 | $self->has_column($key) |
125 | && |
126 | exists $self->column_info($key)->{_filter_info} |
127 | ) { |
128 | $self->set_filtered_column($key, delete $attrs->{$key}); |
7c6fa77f |
129 | |
130 | # FIXME update() reaches directly into the object-hash |
131 | # and we may *not* have a filtered value there - thus |
132 | # the void-ctx filter-trigger |
133 | $self->get_column($key) unless exists $self->{_column_data}{$key}; |
7b461f8a |
134 | } |
135 | } |
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136 | |
7b461f8a |
137 | return $self->next::method($attrs, @rest); |
138 | } |
139 | |
7b461f8a |
140 | sub new { |
141 | my ($class, $attrs, @rest) = @_; |
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142 | my $source = $attrs->{-result_source} |
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143 | or $class->throw_exception('Sourceless rows are not supported with DBIx::Class::FilterColumn'); |
144 | |
9b2c0de6 |
145 | my $obj = $class->next::method($attrs, @rest); |
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146 | foreach my $key (keys %{$attrs||{}}) { |
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147 | if ($obj->has_column($key) && |
148 | exists $obj->column_info($key)->{_filter_info} ) { |
491c8ff9 |
149 | $obj->set_filtered_column($key, $attrs->{$key}); |
7b461f8a |
150 | } |
151 | } |
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152 | |
7b461f8a |
153 | return $obj; |
154 | } |
155 | |
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156 | 1; |
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157 | |
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158 | =head1 NAME |
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159 | |
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160 | DBIx::Class::FilterColumn - Automatically convert column data |
161 | |
162 | =head1 SYNOPSIS |
163 | |
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164 | In your Schema or DB class add "FilterColumn" to the top of the component list. |
165 | |
166 | __PACKAGE__->load_components(qw( FilterColumn ... )); |
167 | |
168 | Set up filters for the columns you want to convert. |
169 | |
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170 | __PACKAGE__->filter_column( money => { |
171 | filter_to_storage => 'to_pennies', |
172 | filter_from_storage => 'from_pennies', |
173 | }); |
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174 | |
175 | sub to_pennies { $_[1] * 100 } |
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176 | |
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177 | sub from_pennies { $_[1] / 100 } |
178 | |
179 | 1; |
180 | |
f10a2e9a |
181 | |
9b2c0de6 |
182 | =head1 DESCRIPTION |
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183 | |
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184 | This component is meant to be a more powerful, but less DWIM-y, |
185 | L<DBIx::Class::InflateColumn>. One of the major issues with said component is |
186 | that it B<only> works with references. Generally speaking anything that can |
187 | be done with L<DBIx::Class::InflateColumn> can be done with this component. |
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188 | |
9b2c0de6 |
189 | =head1 METHODS |
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190 | |
9b2c0de6 |
191 | =head2 filter_column |
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192 | |
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193 | __PACKAGE__->filter_column( colname => { |
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194 | filter_from_storage => 'method'|\&coderef, |
195 | filter_to_storage => 'method'|\&coderef, |
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196 | }) |
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197 | |
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198 | This is the method that you need to call to set up a filtered column. It takes |
199 | exactly two arguments; the first being the column name the second being a hash |
200 | reference with C<filter_from_storage> and C<filter_to_storage> set to either |
201 | a method name or a code reference. In either case the filter is invoked as: |
202 | |
47d7b769 |
203 | $result->$filter_specification ($value_to_filter) |
eec182b6 |
204 | |
205 | with C<$filter_specification> being chosen depending on whether the |
206 | C<$value_to_filter> is being retrieved from or written to permanent |
207 | storage. |
208 | |
209 | If a specific directional filter is not specified, the original value will be |
210 | passed to/from storage unfiltered. |
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211 | |
9b2c0de6 |
212 | =head2 get_filtered_column |
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213 | |
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214 | $obj->get_filtered_column('colname') |
215 | |
216 | Returns the filtered value of the column |
217 | |
218 | =head2 set_filtered_column |
219 | |
220 | $obj->set_filtered_column(colname => 'new_value') |
221 | |
222 | Sets the filtered value of the column |
eec182b6 |
223 | |
224 | =head1 EXAMPLE OF USE |
225 | |
226 | Some databases have restrictions on values that can be passed to |
227 | boolean columns, and problems can be caused by passing value that |
228 | perl considers to be false (such as C<undef>). |
229 | |
230 | One solution to this is to ensure that the boolean values are set |
231 | to something that the database can handle - such as numeric zero |
232 | and one, using code like this:- |
233 | |
234 | __PACKAGE__->filter_column( |
235 | my_boolean_column => { |
236 | filter_to_storage => sub { $_[1] ? 1 : 0 }, |
237 | } |
238 | ); |
239 | |
240 | In this case the C<filter_from_storage> is not required, as just |
241 | passing the database value through to perl does the right thing. |