Handel::Components::Constraints(3)

NAME
Handel::Components::Constraints - Column constraints for schemas

SYNOPSIS
    package MySchema::Table;
    use strict;
    use warnings;
    use base qw/DBIx::Class/;

    __PACKAGE__->load_components('+Handel::Component::Constraints');
    __PACKAGE__->add_constraint('column', 'Constraint Name' => \&checker);

    1;

DESCRIPTION
Handel::Components::Constraints is a simple way to validate column data during inserts/updates using subroutines. It mostly acts as a compatibility layer for subclasses that used "add_constraint" when Handel used Class::DBI.

There is no real reason to load this component into your schema table classes directly. If you add constraints using Handel::Storage->add_constraint, this component will be loaded into the appropriate schema source class automatically.

METHODS

  add_constraint

Arguments: $column, $name, \&sub

Adds a named constraint for the specified column.

    __PACKAGE__->add_constraint('quantity', 'Check Quantity' => \%check_qty);

Note: Always use the real column name in the database, not the accessor alias for the column.

  check_constraints
This loops through all of the configured constraints, calling the specified \&sub. Each sub will receive the following arguments:

    sub mysub {
        my ($value, $source, $column, \%data) = @_;

        if ($value) {
            return 1;
        } else {
            return 0;
        };
    };

value
    The value of the column to be checked.

source
    The result object for the row being updated/inserted.

column
    The name of the column being checked.

data
    A hash reference containing all of the columns and their values. Changing any values in the hash will also change the value inserted/updated in the database.

  insert
Calls "check_constraints" and then inserts the row. See "insert" in DBIx::Class::Row for more information about insert.

  update
Calls "check_constraints" and then updates the row. See "update" in DBIx::Class::Row for more information about update.

AUTHOR
    Christopher H. Laco
    CPAN ID: CLACO
    claco@chrislaco.com
    http://today.icantfocus.com/blog/