in reply to Re^2: Question about __PACKAGE__
in thread Question about __PACKAGE__

When I trace into the source of DBIx::Class, why I did not see any mehtod like table(), add_columns(), or load_components()?

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Re^4: Question about __PACKAGE__
by SpiceMan (Sexton) on Jan 22, 2010 at 04:58 UTC
    found them with grep, though: 
    1:53 spiceman@cynic ~/perl5/lib/perl5 % grep -R 'sub add_columns ' DBIx
DBIx/Class/CDBICompat/ColumnGroups.pm:sub add_columns {
DBIx/Class/CDBICompat/ColumnCase.pm:sub add_columns {
DBIx/Class/DynamicDefault.pm:sub add_columns {
DBIx/Class/TimeStamp.pm:sub add_columns {
DBIx/Class/ResultSource.pm:sub add_columns {
DBIx/Class/ResultSourceProxy.pm:sub add_columns {

1:53 spiceman@cynic ~/perl5/lib/perl5 % grep -R 'sub table ' DBIx
DBIx/Class/ResultSetManager.pm:sub table {
DBIx/Class/ResultSourceProxy/Table.pm:sub table {

1:53 spiceman@cynic ~/perl5/lib/perl5 % grep -R 'sub load_components ' .
./Class/C3/Componentised.pm:sub load_components {
[reply]
Re^4: Question about __PACKAGE__
by sman (Beadle) on Jan 22, 2010 at 05:36 UTC
    I found the corresponding classes that these three class methods belong to:

    DBIx::Class::ResultSourceProxy::Table
    table()
    add_columns()

    Class::C3::Componentised
    load_components()

    And I also know Class::C3::Componentised is the parent class of DBIx::Class that is the parent of Item, so this makes sense. But I don't know the relationship between DBIx::Class::ResultSourceProxy::Table and DBIx::Class.

    Any idea?
[reply]

      Taking an educated guess with grep is indeed the easiest path sometimes.

      load_components loads modules and adds them as base class (kinda like use base does).

      load_components('Core') loads DBIx::Class::Core and makes DBIx::Class::Core a base class of your class.

      DBIx::Class::Core similarly uses load_components loads a number of modules (including DBIx::Class::ResultSourceProxy::Table) and adds them to its list of base classes. 

      package Result::Item;

use strict;
use warnings;

use base 'DBIx::Class';

__PACKAGE__->load_components( "InflateColumn::DateTime", "Core" );

print "Parents of Result::Item:\n";
print "$_\n" for @Result::Item::ISA;
print "\n";
print "Parents of DBIx::Class::Core:\n";
print "$_\n" for @DBIx::Class::Core::ISA;

      [download]
      Parents of Result::Item:
DBIx::Class::InflateColumn::DateTime
DBIx::Class::Core
DBIx::Class

Parents of DBIx::Class::Core:
DBIx::Class::Relationship
DBIx::Class::InflateColumn
DBIx::Class::PK::Auto
DBIx::Class::PK
DBIx::Class::Row
DBIx::Class::ResultSourceProxy::Table
DBIx::Class

      [download]
[reply]
[d/l]
[select]
        I got your point. I guess I can change class Item to inherit from DBIx::Class::Core instead of DBIx::Class and comment out this line : 
        __PACKAGE__->load_components( "InflateColumn::DateTime", "Core" );

        [download]
        Am I right?
[reply]
[d/l]
        Thanks for your reply.
[reply]

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