=head1 NAME Catalyst::Manual::Tutorial::AdvancedCRUD::FormFu - Catalyst Tutorial - Chapter 9: Advanced CRUD - FormFu =head1 OVERVIEW This is B for the Catalyst tutorial. L =over 4 =item 1 L =item 2 L =item 3 L =item 4 L =item 5 L =item 6 L =item 7 L =item 8 L =item 9 B =item 10 L =back =head1 DESCRIPTION This portion of the tutorial explores L and how it can be used to manage forms, perform validation of form input, as well as save and restore data to/from the database. This was written using HTML::FormFu version 0.03007. See L for additional form management options other than L. =head1 Install C If you are following along in Debian 5, it turns out that some of the modules we need are not yet available as Debian packages at the time this was written. To install it with a combination of Debian packages and traditional CPAN modules, first use C to install most of the modules: we need to install the L package: sudo aptitude -y install libhtml-formfu-perl libmoose-perl \ libregexp-assemble-perl libhtml-formfu-model-dbic-perl ... sudo aptitude clean Then use the following command to install directly from CPAN the modules that aren't available as Debian packages: sudo cpan Catalyst::Component::InstancePerContext Catalyst::Controller::HTML::FormFu =head1 C FORM CREATION This section looks at how L can be used to add additional functionality to the manually created form from Chapter 4. =head2 Inherit From C First, change your C to inherit from L by changing the C line from the default of: use parent 'Catalyst::Controller'; to use the FormFu base controller class: use parent 'Catalyst::Controller::HTML::FormFu'; =head2 Add Action to Display and Save the Form Open C in your editor and add the following method: =head2 formfu_create Use HTML::FormFu to create a new book =cut sub formfu_create :Chained('base') :PathPart('formfu_create') :Args(0) :FormConfig { my ($self, $c) = @_; # Get the form that the :FormConfig attribute saved in the stash my $form = $c->stash->{form}; # Check if the form has been submitted (vs. displaying the initial # form) and if the data passed validation. "submitted_and_valid" # is shorthand for "$form->submitted && !$form->has_errors" if ($form->submitted_and_valid) { # Create a new book my $book = $c->model('DB::Books')->new_result({}); # Save the form data for the book $form->model->update($book); # Set a status message for the user $c->flash->{status_msg} = 'Book created'; # Return to the books list $c->response->redirect($c->uri_for($self->action_for('list'))); $c->detach; } else { # Get the authors from the DB my @author_objs = $c->model("DB::Authors")->all(); # Create an array of arrayrefs where each arrayref is an author my @authors; foreach (sort {$a->last_name cmp $b->last_name} @author_objs) { push(@authors, [$_->id, $_->last_name]); } # Get the select added by the config file my $select = $form->get_element({type => 'Select'}); # Add the authors to it $select->options(\@authors); } # Set the template $c->stash->{template} = 'books/formfu_create.tt2'; } =head2 Create a Form Config File Although C supports any configuration file handled by L, most people tend to use YAML. First create a directory to hold your form configuration files: mkdir -p root/forms/books Then create the file C and enter the following text: --- # indicator is the field that is used to test for form submission indicator: submit # Start listing the form elements elements: # The first element will be a text field for the title - type: Text name: title label: Title # This is an optional 'mouse over' title pop-up attributes: title: Enter a book title here # Another text field for the numeric rating - type: Text name: rating label: Rating attributes: title: Enter a rating between 1 and 5 here # Add a drop-down list for the author selection. Note that we will # dynamically fill in all the authors from the controller but we # could manually set items in the drop-list by adding this YAML code: # options: # - [ '1', 'Bastien' ] # - [ '2', 'Nasseh' ] - type: Select name: authors label: Author # The submit button - type: Submit name: submit value: Submit B Copying and pasting YAML from perl documentation is sometimes tricky. See the L section of this document for a more foolproof config format. =head2 Update the CSS Edit C and add the following lines to the bottom of the file: ... input { display: block; } select { display: block; } .submit { padding-top: .5em; display: block; } These changes will display form elements vertically. Note that the existing definition of the C<.error> class is pulling the color scheme settings from the C file that was created by the TTSite helper. This allows control over the CSS color settings from a single location. =head2 Create a Template Page To Display The Form Open C in your editor and enter the following: [% META title = 'Create/Update Book' %] [%# Render the HTML::FormFu Form %] [% form %]

Return to book list

=head2 Add Links for Create and Update via C Open C in your editor and add the following to the bottom of the existing file: ...

HTML::FormFu: Create

This adds a new link to the bottom of the book list page that we can use to easily launch our HTML::FormFu-based form. =head2 Test The Create Form Press C to kill the previous server instance (if it's still running) and restart it: $ script/myapp_server.pl Login as C (password: mypass). Once at the Book List page, click the new HTML::FormFu "Create" link at the bottom to display the form. Fill in the following values: Title = "Internetworking with TCP/IP Vol. II", Rating = "4", and Author = "Comer". Click Submit, and you will be returned to the Book List page with a "Book created" status message displayed. Also note that this implementation allows you to can create books with bogus information. Although we have constrained the authors with the drop-down list (note that this isn't bulletproof because we still have not prevented a user from "hacking" the form to specify other values), there are no restrictions on items such as the length of the title (for example, you can create a one-letter title) and value for the rating (you can use any number you want, and even non-numeric values with SQLite). The next section will address this concern. B Depending on the database you are using and how you established the columns in your tables, the database could obviously provide various levels of "type enforcement" on your data. The key point being made in the previous paragraph is that the I itself is not performing any validation. =head1 C VALIDATION AND FILTERING Although the use of L in the previous section did provide an automated mechanism to build the form, the real power of this module stems from functionality that can automatically validate and filter the user input. Validation uses constraints to be sure that users input appropriate data (for example, that the email field of a form contains a valid email address). Filtering can also be used to remove extraneous whitespace from fields or to escape meta-characters in user input. =head2 Add Constraints Open C in your editor and update it to match: --- # indicator is the field that is used to test for form submission indicator: submit # Start listing the form elements elements: # The first element will be a text field for the title - type: Text name: title label: Title # This is an optional 'mouse over' title pop-up attributes: title: Enter a book title here # Add constraints for the field constraints: # Force the length to be between 5 and 40 chars - type: Length min: 5 max: 40 # Override the default of 'Invalid input' message: Length must be between 5 and 40 characters # Another text field for the numeric rating - type: Text name: rating label: Rating attributes: title: Enter a rating between 1 and 5 here # Use Filter to clean up the input data # Could use 'NonNumeric' below, but since Filters apply *before* # constraints, it would conflict with the 'Integer' constraint below. # So let's skip this and just use the constraint. #filter: # Remove everything except digits #- NonNumeric # Add constraints to the field constraints: # Make sure it's a number - type: Integer message: "Required. Digits only, please." # Check the min & max values - type: Range min: 1 max: 5 message: "Must be between 1 and 5." # Add a select list for the author selection. Note that we will # dynamically fill in all the authors from the controller but we # could manually set items in the select by adding this YAML code: # options: # - [ '1', 'Bastien' ] # - [ '2', 'Nasseh' ] - type: Select name: authors label: Author # Convert the drop-down to a multi-select list multiple: 1 # Display 3 entries (user can scroll to see others) size: 3 # One could argue we don't need to do filters or constraints for # a select list, but it's smart to do validation and sanity # checks on this data in case a user "hacks" the input # Add constraints to the field constraints: # Make sure it's a number - Integer # The submit button - type: Submit name: submit value: Submit # Global filters and constraints. constraints: # The user cannot leave any fields blank - Required # If not all fields are required, move the Required constraint to the # fields that are filter: # Remove whitespace at both ends - TrimEdges # Escape HTML characters for safety - HTMLEscape B Copying and pasting YAML from perl documentation is sometimes tricky. See the L section of this document for a more foolproof config format. The main changes are: =over 4 =item * The C