Catalyst::Manual::Tutorial::09_AdvancedCRUD::09_FormHandUser3Contributed Perl DocuCatalyst::Manual::Tutorial::09_AdvancedCRUD::09_FormHandler(3pm)

NAME

       Catalyst::Manual::Tutorial::09_AdvancedCRUD::09_FormHandler - Catalyst Tutorial - Chapter 9: Advanced CRUD - FormHandler

OVERVIEW

       This is Chapter 9 of 10 for the Catalyst tutorial.

       Tutorial Overview

       1.  Introduction

       2.  Catalyst Basics

       3.  More Catalyst Basics

       4.  Basic CRUD

       5.  Authentication

       6.  Authorization

       7.  Debugging

       8.  Testing

       9.  09_Advanced CRUD::09_FormHandler

       10. Appendices

DESCRIPTION

       This portion of the tutorial explores 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 Catalyst::Manual::Tutorial::09_AdvancedCRUD for additional form management options other than HTML::FormHandler.

Install HTML::FormHandler
       Use the following command to install HTML::FormHandler::Model::DBIC directly from CPAN:

	   sudo cpan HTML::FormHandler::Model::DBIC

       It will install HTML::FormHandler as a prerequisite.

       Also, add:

	   requires 'HTML::FormHandler::Model::DBIC';

       to your "Makefile.PL".

HTML
::FormHandler FORM CREATION
       This section looks at how HTML::FormHandler can be used to add additional functionality to the manually created form from Chapter 4.

   Using FormHandler in your controllers
       FormHandler doesn't have a Catalyst base controller, because interfacing to a form is only a couple of lines of code.

   Create a Book Form
       Create the directory "lib/MyApp/Form". Create "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;

   Add Action to Display and Save the Form
       At the top of the "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;
	       # Set a status message for the user & return to books list
	       $c->response->redirect($c->uri_for($self->action_for('list'),
		   {mid => $c->set_status_msg("Book created")}));
	   }

       These two methods could be combined at this point, but we'll use the 'form' method later when we implement 'edit'.

   Create a Template Page To Display The Form
       Open "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>

   Add Link for Create
       Open "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.

   Test The HTML::FormHandler Create Form
       Press "Ctrl-C" to kill the previous server instance (if it's still running) and restart it:

	   $ script/myapp_server.pl

       Login as "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.

   Add Constraints
       Open "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 HTML::FormHandler::Manual.

   Try Out the Updated Form
       Press "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 "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.

   Create the 'edit' method
       Edit "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 "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>

   Try Out the Edit/Update Feature
       Press "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 "test01" and go to the <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.

   See additional documentation on FormHandler
       HTML::FormHandler::Manual

       HTML::FormHandler

	  #formhandler on irc.perl.org

	  mailing list: http://groups.google.com/group/formhandler

	  code: http://github.com/gshank/html-formhandler/tree/master

AUTHOR

       Gerda Shank, "gshank@cpan.org"

       Copyright 2009, Gerda Shank, Perl Artistic License

perl v5.14.2							    2012-01-20	  Catalyst::Manual::Tutorial::09_AdvancedCRUD::09_FormHandler(3pm)