X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=blobdiff_plain;f=lib%2FDBIx%2FClass%2FFilterColumn.pm;h=feef4f1610d0fd1e6619432a5e9c174e4abb8daa;hb=fcf32d045;hp=f378ed77ac96b512fd676f0fd0b1a883feb33534;hpb=4c0c303898ebd56e8e15a6402608be3a23d242ca;p=dbsrgits%2FDBIx-Class.git diff --git a/lib/DBIx/Class/FilterColumn.pm b/lib/DBIx/Class/FilterColumn.pm index f378ed7..feef4f1 100644 --- a/lib/DBIx/Class/FilterColumn.pm +++ b/lib/DBIx/Class/FilterColumn.pm @@ -1,5 +1,4 @@ package DBIx::Class::FilterColumn; - use strict; use warnings; @@ -8,15 +7,24 @@ use base qw/DBIx::Class::Row/; sub filter_column { my ($self, $col, $attrs) = @_; + my $colinfo = $self->column_info($col); + + $self->throw_exception('FilterColumn does not work with InflateColumn') + if $self->isa('DBIx::Class::InflateColumn') && + defined $colinfo->{_inflate_info}; + $self->throw_exception("No such column $col to filter") unless $self->has_column($col); - $self->throw_exception("filter_column needs attr hashref") + $self->throw_exception('filter_column expects a hashref of filter specifications') unless ref $attrs eq 'HASH'; - $self->column_info($col)->{_filter_info} = $attrs; - my $acc = $self->column_info($col)->{accessor}; - $self->mk_group_accessors('value' => [ (defined $acc ? $acc : $col), $col]); + $self->throw_exception('An invocation of filter_column() must specify either a filter_from_storage or filter_to_storage') + unless $attrs->{filter_from_storage} || $attrs->{filter_to_storage}; + + $colinfo->{_filter_info} = $attrs; + my $acc = $colinfo->{accessor}; + $self->mk_group_accessors(filtered_column => [ (defined $acc ? $acc : $col), $col]); return 1; } @@ -30,10 +38,9 @@ sub _column_from_storage { return $value unless exists $info->{_filter_info}; - my $filter = $info->{_filter_info}{from_storage}; - $self->throw_exception("No inflator for $col") unless defined $filter; + my $filter = $info->{_filter_info}{filter_from_storage}; - return $self->$filter($value); + return defined $filter ? $self->$filter($value) : $value; } sub _column_to_storage { @@ -44,12 +51,12 @@ sub _column_to_storage { return $value unless exists $info->{_filter_info}; - my $unfilter = $info->{_filter_info}{to_storage}; - $self->throw_exception("No unfilter for $col") unless defined $unfilter; - return $self->$unfilter($value); + my $unfilter = $info->{_filter_info}{filter_to_storage}; + + return defined $unfilter ? $self->$unfilter($value) : $value; } -sub get_value { +sub get_filtered_column { my ($self, $col) = @_; $self->throw_exception("$col is not a filtered column") @@ -63,41 +70,173 @@ sub get_value { return $self->{_filtered_column}{$col} = $self->_column_from_storage($col, $val); } -sub set_value { - my ($self, $col, $filtered) = @_; +sub get_column { + my ($self, $col) = @_; + if (exists $self->{_filtered_column}{$col}) { + return $self->{_column_data}{$col} ||= $self->_column_to_storage ($col, $self->{_filtered_column}{$col}); + } - $self->set_column($col, $self->_column_to_storage($col, $filtered)); + return $self->next::method ($col); +} + +# sadly a separate codepath in Row.pm ( used by insert() ) +sub get_columns { + my $self = shift; + + foreach my $col (keys %{$self->{_filtered_column}||{}}) { + $self->{_column_data}{$col} ||= $self->_column_to_storage ($col, $self->{_filtered_column}{$col}) + if exists $self->{_filtered_column}{$col}; + } + + $self->next::method (@_); +} + +sub store_column { + my ($self, $col) = (shift, @_); + # blow cache delete $self->{_filtered_column}{$col}; - return $filtered; + $self->next::method(@_); +} + +sub set_filtered_column { + my ($self, $col, $filtered) = @_; + + # do not blow up the cache via set_column unless necessary + # (filtering may be expensive!) + if (exists $self->{_filtered_column}{$col}) { + return $filtered + if ($self->_eq_column_values ($col, $filtered, $self->{_filtered_column}{$col} ) ); + + $self->make_column_dirty ($col); # so the comparison won't run again + } + + $self->set_column($col, $self->_column_to_storage($col, $filtered)); + + return $self->{_filtered_column}{$col} = $filtered; } sub update { my ($self, $attrs, @rest) = @_; + foreach my $key (keys %{$attrs||{}}) { - if ($self->has_column($key) && - exists $self->column_info($key)->{_filter_info}) { - my $val = delete $attrs->{$key}; - $self->set_value($key, $val); - $attrs->{$key} = $self->_column_to_storage($key, $val) + if ( + $self->has_column($key) + && + exists $self->column_info($key)->{_filter_info} + ) { + $self->set_filtered_column($key, delete $attrs->{$key}); + + # FIXME update() reaches directly into the object-hash + # and we may *not* have a filtered value there - thus + # the void-ctx filter-trigger + $self->get_column($key) unless exists $self->{_column_data}{$key}; } } + return $self->next::method($attrs, @rest); } - sub new { my ($class, $attrs, @rest) = @_; + my $source = $attrs->{-result_source} + or $class->throw_exception('Sourceless rows are not supported with DBIx::Class::FilterColumn'); + + my $obj = $class->next::method($attrs, @rest); foreach my $key (keys %{$attrs||{}}) { - if ($class->has_column($key) && - exists $class->column_info($key)->{_filter_info} ) { - $attrs->{$key} = $class->_column_to_storage($key, delete $attrs->{$key}) + if ($obj->has_column($key) && + exists $obj->column_info($key)->{_filter_info} ) { + $obj->set_filtered_column($key, $attrs->{$key}); } } - my $obj = $class->next::method($attrs, @rest); + return $obj; } - 1; + +=head1 NAME + +DBIx::Class::FilterColumn - Automatically convert column data + +=head1 SYNOPSIS + +In your Schema or DB class add "FilterColumn" to the top of the component list. + + __PACKAGE__->load_components(qw( FilterColumn ... )); + +Set up filters for the columns you want to convert. + + __PACKAGE__->filter_column( money => { + filter_to_storage => 'to_pennies', + filter_from_storage => 'from_pennies', + }); + + sub to_pennies { $_[1] * 100 } + + sub from_pennies { $_[1] / 100 } + + 1; + + +=head1 DESCRIPTION + +This component is meant to be a more powerful, but less DWIM-y, +L. One of the major issues with said component is +that it B works with references. Generally speaking anything that can +be done with L can be done with this component. + +=head1 METHODS + +=head2 filter_column + + __PACKAGE__->filter_column( colname => { + filter_from_storage => 'method'|\&coderef, + filter_to_storage => 'method'|\&coderef, + }) + +This is the method that you need to call to set up a filtered column. It takes +exactly two arguments; the first being the column name the second being a hash +reference with C and C set to either +a method name or a code reference. In either case the filter is invoked as: + + $row_obj->$filter_specification ($value_to_filter) + +with C<$filter_specification> being chosen depending on whether the +C<$value_to_filter> is being retrieved from or written to permanent +storage. + +If a specific directional filter is not specified, the original value will be +passed to/from storage unfiltered. + +=head2 get_filtered_column + + $obj->get_filtered_column('colname') + +Returns the filtered value of the column + +=head2 set_filtered_column + + $obj->set_filtered_column(colname => 'new_value') + +Sets the filtered value of the column + +=head1 EXAMPLE OF USE + +Some databases have restrictions on values that can be passed to +boolean columns, and problems can be caused by passing value that +perl considers to be false (such as C). + +One solution to this is to ensure that the boolean values are set +to something that the database can handle - such as numeric zero +and one, using code like this:- + + __PACKAGE__->filter_column( + my_boolean_column => { + filter_to_storage => sub { $_[1] ? 1 : 0 }, + } + ); + +In this case the C is not required, as just +passing the database value through to perl does the right thing.