=head1 NAME
Catalyst::Manual::Tutorial::09_AdvancedCRUD::09_FormHandler - Catalyst Tutorial - Chapter 9: Advanced CRUD - FormHandler
=head1 OVERVIEW
This is B<Chapter 9 of 10> for the Catalyst tutorial.
L<Tutorial Overview|Catalyst::Manual::Tutorial>
=over 4
=item 1
L<Introduction|Catalyst::Manual::Tutorial::01_Intro>
=item 2
L<Catalyst Basics|Catalyst::Manual::Tutorial::02_CatalystBasics>
=item 3
L<More Catalyst Basics|Catalyst::Manual::Tutorial::03_MoreCatalystBasics>
=item 4
L<Basic CRUD|Catalyst::Manual::Tutorial::04_BasicCRUD>
=item 5
L<Authentication|Catalyst::Manual::Tutorial::05_Authentication>
=item 6
L<Authorization|Catalyst::Manual::Tutorial::06_Authorization>
=item 7
L<Debugging|Catalyst::Manual::Tutorial::07_Debugging>
=item 8
L<Testing|Catalyst::Manual::Tutorial::08_Testing>
=item 9
B<09_Advanced CRUD::09_FormHandler>
=item 10
L<Appendices|Catalyst::Manual::Tutorial::10_Appendices>
=back
=head1 DESCRIPTION
This portion of the tutorial explores
L<HTML::FormHandler|HTML::FormHandler> and how it can be used to manage
forms, perform validation of form input, and save and restore data
to or from the database. This was written using HTML::FormHandler version
0.28001.
See
L<Catalyst::Manual::Tutorial::09_AdvancedCRUD|Catalyst::Manual::Tutorial::09_AdvancedCRUD>
for additional form management options other than
L<HTML::FormHandler|HTML::FormHandler>.
=head1 Install HTML::FormHandler
Use the following command to install L<HTML::FormHandler::Model::DBIC> directly
from CPAN:
sudo cpan HTML::FormHandler::Model::DBIC
It will install L<HTML::FormHandler> as a prerequisite.
Also, add:
requires 'HTML::FormHandler::Model::DBIC';
to your C<Makefile.PL>.
=head1 HTML::FormHandler FORM CREATION
This section looks at how L<HTML::FormHandler|HTML::FormHandler> can be used to
add additional functionality to the manually created form from Chapter 4.
=head2 Using FormHandler in your controllers
FormHandler dosen't have a Catalyst base controller, because interfacing
to a form is only a couple of lines of code.
=head2 Create a Book Form
Create the directory C<lib/MyApp/Form>. Create C<lib/MyApp/Form/Book.pm>:
package MyApp::Form::Book;
use HTML::FormHandler::Moose;
extends 'HTML::FormHandler::Model::DBIC';
use namespace::autoclean;
has '+item_class' => ( default =>'Books' );
has_field 'title';
has_field 'rating' => ( type => 'Integer' );
has_field 'authors' => ( type => 'Multiple', label_column => 'last_name' );
has_field 'submit' => ( type => 'Submit', value => 'Submit' );
__PACKAGE__->meta->make_immutable;
1;
=head2 Add Action to Display and Save the Form
At the top of the C<lib/MyApp/Controller/Books.pm> add:
use MyApp::Form::Book;
Add the following methods:
=head2 create
Use HTML::FormHandler to create a new book
=cut
sub create : Chained('base') PathPart('create') Args(0) {
my ($self, $c ) = @_;
my $book = $c->model('DB::Book')->new_result({});
return $self->form($c, $book);
}
=head2 form
Process the FormHandler book form
=cut
sub form {
my ( $self, $c, $book ) = @_;
my $form = MyApp::Form::Book->new;
# Set the template
$c->stash( template => 'books/form.tt2', form => $form );
$form->process( item => $book, params => $c->req->params );
return unless $form->validated;
$c->flash( message => 'Book created' );
# Redirect the user back to the list page
$c->response->redirect($c->uri_for($self->action_for('list')));
}
These two methods could be combined at this point, but we'll use the 'form'
method later when we implement 'edit'.
=head2 Create a Template Page To Display The Form
Open C<root/src/books/form.tt2> in your editor and enter the following:
[% META title = 'Create/Update Book' %]
[%# Render the HTML::FormHandler Form %]
[% form.render %]
<p><a href="[% c.uri_for(c.controller.action_for('list')) %]">Return to book list</a></p>
=head2 Add Link for Create
Open C<root/src/books/list.tt2> in your editor and add the following to
the bottom of the existing file:
...
<p>
HTML::FormHandler:
<a href="[% c.uri_for(c.controller.action_for('create')) %]">Create</a>
</p>
This adds a new link to the bottom of the book list page that we can
use to easily launch our HTML::FormHandler-based form.
=head2 Test The HTML::FormHandler Create Form
Press C<Ctrl-C> to kill the previous server instance (if it's still
running) and restart it:
$ script/myapp_server.pl
Login as C<test01> (password: mypass). Once at the Book List page,
click the new HTML::Formhandler "Create" link at the bottom to display the
form. Fill in the following values:
Title = "Internetworking with TCP/IP Vol. II"
Rating = "4"
Author = "Comer"
Click the Submit button, and you will be returned to the Book List page
with a "Book created" status message displayed.
Note that because the 'Author' column is a Select list, only the authors
in the database can be entered. The 'ratings' field will only accept
integers.
=head2 Add Constraints
Open C<lib/MyApp/Form/Book.pm> in your editor.
Restrict the title size and make it required:
has_field 'title' => ( minlength => 5, maxlength => 40, required => 1 );
Add range constraints to the 'rating' field:
has_field 'rating' => ( type => 'Integer', range_start => 1, range_end => 5 );
The 'authors' relationship is a 'many-to-many' pseudo-relation, so this field
can be set to Multiple to allow the selection of multiple authors; also, make it
required:
has_field 'authors' => ( type => 'Multiple', label_column => 'last_name',
required => 1 );
Note: FormHandler automatically strips whitespace at the beginning and
end of fields. If you want some other kind of stripping (or none) you
can specify it explicitly; see L<HTML::FormHandler::Manual>.
=head2 Try Out the Updated Form
Press C<Ctrl-C> to kill the previous server instance (if it's still
running) and restart it:
$ script/myapp_server.pl
Make sure you are still logged in as C<test01> and try adding a book
with various errors: title less than 5 characters, non-numeric rating, a
rating of 0 or 6, etc. Also try selecting one, two, and zero authors.
=head2 Create the 'edit' method
Edit C<lib/MyApp/Controller/Books.pm> and add the following method:
=head2 edit
Edit an existing book with FormHandler
=cut
sub edit : Chained('object') PathPart('edit') Args(0) {
my ( $self, $c ) = @_;
return $self->form($c, $c->stash->{object});
}
Update the C<root/src/books/list.tt2>, adding an 'edit' link below the
"Delete" link to use the FormHandler edit method:
<td>
[% # Add a link to delete a book %]
<a href="[% c.uri_for(c.controller.action_for('delete'), [book.id]) %]">Delete</a>
[% # Add a link to edit a book %]
<a href="[% c.uri_for(c.controller.action_for('edit'), [book.id]) %]">Edit</a>
</td>
=head2 Try Out the Edit/Update Feature
Press C<Ctrl-C> to kill the previous server instance (if it's still
running) and restart it:
$ script/myapp_server.pl
Make sure you are still logged in as C<test01> and go to the
L<http://localhost:3000/books/list> URL in your browser. Click the
"Edit" link next to "Internetworking with TCP/IP Vol. II", change the
rating to a 3, the "II" at end of the title to the number "2", add
Stevens as a co-author (control-click), and click Submit. You will then
be returned to the book list with a "Book edited" message at the top in
green. Experiment with other edits to various books.
=head2 See additional documentation on FormHandler
L<HTML::FormHandler::Manual>
L<HTML::FormHandler>
#formhandler on irc.perl.org
mailing list: http://groups.google.com/group/formhandler
code: http://github.com/gshank/html-formhandler/tree/master
=head1 AUTHOR
Gerda Shank, C<gshank@cpan.org>
Copyright 2009, Gerda Shank, Perl Artistic License