NAME

Gantry::Plugins::CRUD - helper for somewhat interesting CRUD work

SYNOPSIS

    use Gantry::Plugins::CRUD;

    my $user_crud = Gantry::Plugins::CRUD->new(
        add_action      => \&user_insert,
        edit_action     => \&user_update,
        delete_action   => \&user_delete,
        form            => \&user_form,
        redirect        => \&redirect_function,
        template        => 'your.tt',  # defulats to form.tt
        text_descr      => 'database row description',
        use_clean_dates => 1,
        turn_off_clean_params => 1,
    );

    sub do_add {
        my ( $self ) = @_;
        $user_crud->add( $self, { data => \@_ } );
    }

    sub user_insert {
        my ( $self, $form_params, $data ) = @_;
        # $data is the value of data from do_add

        my $row = My::Model->create( $params );
        $row->dbi_commit();
    }

    # Similarly for do_delete

    sub do_delete {
        my ( $self, $doomed_id, $confirm ) = @_;
        $user_crud->delete( $self, $confirm, { id => $doomed_id } );
    }

    sub user_delete {
        my ( $self, $data ) = @_;

        my $doomed = My::Model->retrieve( $data->{id} );

        $doomed->delete;
        My::Model->dbi_commit;
    }

DESCRIPTION

This plugin helps you perform Create, Update, and Delete (commonly called CRUD, except that R is retrieve which you still have to implement separately).

Warning: most plugins export methods into your package, this one does NOT.

Normally, you can use Gantry::Plugins::AutoCRUD when you are controlling a single table. But, since its do_add, do_edit, and do_delete are genuine template methods*, sometimes it is not enough. For instance, if you need to allow a regular user and an admin edit for the same database table, you need two methods for each action (two for do_add, two for do_edit, and two for do_delete). This module can help.

* A template method has a series of steps. At each step, it calls a method via a hard coded name.

This module still does basically the same things that AutoCRUD does:

    redirect to listing page if user presses cancel
    if form parameters are valid:
        callback to action method
    else:
        if method is POST:
            add form validation errors
        (re)display form

METHODS

This is an object oriented only module (it doesn't export like the other plugins).

new

Constructs a new CRUD helper. Pass in a list of the following callbacks and config parameters:

add_action (a code ref)

Called with:

    your self object
    hash of form parameters
    the data you passed to add

Called only when the form parameters are valid. You should insert into the database and not die (unless the insert fails, then feel free to die). You don't need to change your location, but you may.

edit_action (a code ref)

Called with:

    your self object
    hash of form parameters
    the data you passed to edit

Called only when form parameters are valid. You should update and not die (unless the update fails, then feel free to die). You don't need to change your location, but you may.

delete_action (a code ref)

Called with:

    your self object
    the data you passed to delete

Called only when the user has confirmed that a row should be deleted. You should delete the corresponding row and not die (unless the delete fails, then feel free to die). You don't need to change your location, but you may.

form (a code ref)

Called with:

    your self object
    the data you passed to add or edit

This needs to return just like the _form method required by Gantry::Plugins::AutoCRUD. See its docs for details. The only difference between these is that the AutoCRUD calls _form with your self object and the row being edited (during editing) whereas this method ALWAYS receives both your self object and the data you supplied.

redirect (optional, defaults to $your_self->location() )

NOTE WELL: It is a bad idea to name your redirect callback 'redirect'. That name is used internally in Gantry.pm.

Where you want to go whenever an action is complete. If you need control on a per action basis end your action callback with:

    $your_self->location( 'http://location.of/your/choice' );

Your redirect is called with your self object and the data you passed to the add, edit, or delete method of this package. This allows you complete control, even on cancellation.

template (optional, defaults to form.tt)

The name of your form template.

text_descr

The text string used in the page titles and in the delete confirmation message.

use_clean_dates (optional, defaults to false)

This is ignored unless you turn_off_clean_params, since it is redundant when clean_params is in use.

Make this true if you want your dates cleaned immediately before your add and edit callbacks are invoked.

Cleaning sets any false fields marked as dates in the form fields list to undef. This allows your ORM to correctly insert them as nulls instead of trying to insert them as blank strings (which is fatal, at least in PostgreSQL).

For this to work your form fields must have this key: <is = 'date'>>.

turn_off_clean_params (optional, defaults to false)

By default, right before an SQL insert or update, the params hash from the form is passed through the clean_params routine which sets all non-boolean fields which are false to undef. This prevents SQL errors with ORMs that can correctly translate blank strings into nulls for non-string types.

If you really don't want this routine, set turn_off_clean_params. If you turn it off, you can use_clean_dates, which only sets false dates to undef.

Note that in all cases the submit key is removed from the params hash by this module before any callback is made.

add

Call this in your do_add on a Gantry::Plugins::CRUD instance:

    sub do_special_add {
        my $self = shift;
        $crud_obj->add( $self, { data => \@_ } );
    }

It will die unless you passed the following to the constructor:

        add_action
        form

You may also pass redirect which must return a location suitable for passing to $your_self->relocate.

edit

Call this in your do_edit on a Gantry::Plugins::CRUD instance:

    sub do_special_edit {
        my $self = shift;
        my $id   = shift;
        my $row  = Data::Model->retrieve( $id );
        $crud_obj->edit( $self, { id => $id, row => $row } );
    }

It will die unless you passed the following to the constructor:

        edit_action
        form

You may also pass redirect which must return a location suitable for passing to $your_self->relocate.

delete

Call this in your do_delete on a Gantry::Plugins::CRUD instance:

    sub do_special_delete {
        my $self    = shift;
        my $id      = shift;
        my $confirm = shift;
        $crud_obj->delete( $self, $confirm, { id => $id } );
    }

The $confirm argument is yes if the delete should go ahead and anything else otherwise. This allows our standard practice of having delete urls like this:

    http://somesite.example.com/item/delete/4

which leads to the confirmation form whose submit action is:

    http://somesite.example.com/item/delete/4/yes

which is taken as confirmation.

It will die unless you passed the following to the constructor:

        delete_action

You may also pass redirect which must return a location suitable for passing to $your_self->relocate.

You can pick an choose which CRUD help you want from this module. It is designed to give you maximum flexibility, while doing the most repetative things in a reasonable way. It is perfectly good use of this module to have only one method which calls edit. On the other hand, you might have two methods that call edit on two different instances, two methods that call add on those same instances and a method that calls delete on one of the instances. Mix and match.

SEE ALSO

 Gantry::Plugins::AutoCRUD (for simpler situations)

 Gantry and the other Gantry::Plugins

LIMITATIONS

Currently only one redirection can be defined. You can get more control by ending your action callback like this:

    return $self->relocate( 'http://location.of/your/choice' );

AUTHOR

Phil Crow <philcrow2000@yahoo.com>

COPYRIGHT and LICENSE

Copyright (c) 2005, Phil Crow

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself, either Perl version 5.8.6 or, at your option, any later version of Perl 5 you may have available.