5 Catalyst::Manual::Tutorial::AdvancedCRUD::FormFu - Catalyst Tutorial - Part 9: Advanced CRUD - FormFu
10 This is B<Part 9 of 10> for the Catalyst tutorial.
12 L<Tutorial Overview|Catalyst::Manual::Tutorial>
18 L<Introduction|Catalyst::Manual::Tutorial::Intro>
22 L<Catalyst Basics|Catalyst::Manual::Tutorial::CatalystBasics>
26 L<More Catalyst Basics|Catalyst::Manual::Tutorial::MoreCatalystBasics>
30 L<Basic CRUD|Catalyst::Manual::Tutorial::BasicCRUD>
34 L<Authentication|Catalyst::Manual::Tutorial::Authentication>
38 L<Authorization|Catalyst::Manual::Tutorial::Authorization>
42 L<Debugging|Catalyst::Manual::Tutorial::Debugging>
46 L<Testing|Catalyst::Manual::Tutorial::Testing>
50 B<Advanced CRUD::FormFu>
54 L<Appendices|Catalyst::Manual::Tutorial::Appendices>
61 This portion of the tutorial explores L<HTML::FormFu|HTML::FormFu> and
62 how it can be used to manage forms, perform validation of form input,
63 as well as save and restore data to/from the database. This was written
64 using HTML::FormFu version 0.03006.
67 L<Catalyst::Manual::Tutorial::AdvancedCRUD|Catalyst::Manual::Tutorial::AdvancedCRUD>
68 for additional form management options other than
69 L<HTML::FormFu|HTML::FormFu>.
72 =head1 Install C<HTML::FormFu>
74 If you are following along in Ubuntu, it turns out that C<HTML::FormFu>
75 is not yet available as a package at the time this was written. To
76 install it with a combination of C<apt-get> packages and traditional
77 CPAN modules, first use C<apt-get> to install most of the modules
78 required by C<HTML::FormFu>:
80 sudo apt-get install libtest-nowarnings-perl libdatetime-format-builder-perl \
81 libdatetime-format-strptime-perl libdatetime-locale-perl \
82 libhtml-tokeparser-simple-perl liblist-moreutils-perl \
83 libregexp-copy-perl libregexp-common-perl libyaml-syck-perl libparams-util-perl \
84 libcrypt-des-perl libcaptcha-recaptcha-perl libcrypt-cbc-perl \
85 libreadonly-xs-perl libmoose-perl libregexp-assemble-perl
87 Then use the following command to install directly from CPAN the modules
88 that aren't available as Ubuntu/Debian packages via C<apt-get>:
90 sudo cpan File::ShareDir Task::Weaken Config::Any Test::Harness Test::Aggregate \
91 boolean Test::MockTime DateTime::Format::Natural HTML::FormFu \
92 Catalyst::Component::InstancePerContext Catalyst::Controller::HTML::FormFu \
93 HTML::FormFu::Model::DBIC
95 B<Note:> If you are following along with the Ubuntu LiveCD, you might
96 want to make sure you still have adequate free disk space in the root
97 partition with the C<df> command. You can free up some space with
98 C<rm -rf /root/.cpan/*>.
101 =head1 C<HTML::FormFu> FORM CREATION
103 This section looks at how L<HTML::FormFu|HTML::FormFu> can be used to
104 add additional functionality to the manually created form from Part 4.
107 =head2 Inherit From C<Catalyst::Controller::HTML::FormFu>
109 First, change your C<lib/MyApp/Controller/Books.pm> to inherit from
110 L<Catalyst::Controller::HTML::FormFu|Catalyst::Controller::HTML::FormFu>
111 by changing the C<use base> line from the default of:
113 use parent 'Catalyst::Controller';
115 to use the FormFu base controller class:
117 use parent 'Catalyst::Controller::HTML::FormFu';
120 =head2 Add Action to Display and Save the Form
122 Open C<lib/MyApp/Controller/Books.pm> in your editor and add the
127 Use HTML::FormFu to create a new book
131 sub formfu_create :Local :FormConfig {
134 # Get the form that the :FormConfig attribute saved in the stash
135 my $form = $c->stash->{form};
137 # Check if the form has been submitted (vs. displaying the initial
138 # form) and if the data passed validation. "submitted_and_valid"
139 # is shorthand for "$form->submitted && !$form->has_errors"
140 if ($form->submitted_and_valid) {
142 my $book = $c->model('DB::Books')->new_result({});
143 # Save the form data for the book
144 $form->save_to_model($book);
145 # Set a status message for the user
146 $c->flash->{status_msg} = 'Book created';
147 # Return to the books list
148 $c->response->redirect($c->uri_for('list'));
151 # Get the authors from the DB
152 my @authorObjs = $c->model("DB::Authors")->all();
153 # Create an array of arrayrefs where each arrayref is an author
155 foreach (sort {$a->last_name cmp $b->last_name} @authorObjs) {
156 push(@authors, [$_->id, $_->last_name]);
158 # Get the select added by the config file
159 my $select = $form->get_element({type => 'Select'});
160 # Add the authors to it
161 $select->options(\@authors);
165 $c->stash->{template} = 'books/formfu_create.tt2';
169 =head2 Create a Form Config File
171 Although C<HTML::FormFu> supports any configuration file handled by
172 L<Config::Any|Config::Any>, most people tend to use YAML. First
173 create a directory to hold your form configuration files:
175 mkdir -p root/forms/books
177 Then create the file C<root/forms/books/formfu_create.yml> and enter the
181 # indicator is the field that is used to test for form submission
183 # Start listing the form elements
185 # The first element will be a text field for the title
189 # This is an optional 'mouse over' title pop-up
191 title: Enter a book title here
193 # Another text field for the numeric rating
198 title: Enter a rating between 1 and 5 here
200 # Add a drop-down list for the author selection. Note that we will
201 # dynamically fill in all the authors from the controller but we
202 # could manually set items in the drop-list by adding this YAML code:
204 # - [ '1', 'Bastien' ]
205 # - [ '2', 'Nasseh' ]
215 B<NOTE:> Copying and pasting YAML from perl documentation is sometimes
216 tricky. See the L<Config::General Config for this tutorial> section of
217 this document for a more foolproof config format.
220 =head2 Update the CSS
222 Edit C<root/static/css/main.css> and add the following lines to the bottom of
236 These changes will display form elements vertically. Note that the
237 existing definition of the C<.error> class is pulling the color scheme
238 settings from the C<root/lib/config/col> file that was created by the
239 TTSite helper. This allows control over the CSS color settings from a
243 =head2 Create a Template Page To Display The Form
245 Open C<root/src/books/formfu_create.tt2> in your editor and enter the following:
247 [% META title = 'Create/Update Book' %]
249 [%# Render the HTML::FormFu Form %]
252 <p><a href="[% c.uri_for('list') %]">Return to book list</a></p>
255 =head2 Add Links for Create and Update via C<HTML::FormFu>
257 Open C<root/src/books/list.tt2> in your editor and add the following to
258 the bottom of the existing file:
262 <a href="[% c.uri_for('formfu_create') %]">Create</a>
265 This adds a new link to the bottom of the book list page that we can
266 use to easily launch our HTML::FormFu-based form.
269 =head2 Test The <HTML::FormFu> Create Form
271 Press C<Ctrl-C> to kill the previous server instance (if it's still
272 running) and restart it:
274 $ script/myapp_server.pl
276 Login as C<test01> (password: mypass). Once at the Book List page,
277 click the new HTML::FormFu "Create" link at the bottom to display the
278 form. Fill in the following values: Title = "Internetworking with
279 TCP/IP Vol. II", Rating = "4", and Author = "Comer". Click Submit,
280 and you will be returned to the Book List page with a "Book created"
281 status message displayed.
283 Also note that this implementation allows you to can create books with
284 bogus information. Although we have constrained the authors with the
285 drop-down list (note that this isn't bulletproof because we still have
286 not prevented a user from "hacking" the form to specify other values),
287 there are no restrictions on items such as the length of the title (for
288 example, you can create a one-letter title) and value for the rating
289 (you can use any number you want, and even non-numeric values with
290 SQLite). The next section will address this concern.
292 B<Note:> Depending on the database you are using and how you established
293 the columns in your tables, the database could obviously provide various
294 levels of "type enforcement" on your data. The key point being made in
295 the previous paragraph is that the I<web application> itself is not
296 performing any validation.
299 =head1 C<HTML::FormFu> VALIDATION AND FILTERING
301 Although the use of L<HTML::FormFu|HTML::FormFu> in the previous section
302 did provide an automated mechanism to build the form, the real power of
303 this module stems from functionality that can automatically validate and
304 filter the user input. Validation uses constraints to be sure that
305 users input appropriate data (for example, that the email field of a
306 form contains a valid email address). Filtering can also be used to
307 remove extraneous whitespace from fields or to escape meta-characters in
311 =head2 Add Constraints
313 Open C<root/forms/books/formfu_create.yml> in your editor and update it
317 # indicator is the field that is used to test for form submission
319 # Start listing the form elements
321 # The first element will be a text field for the title
325 # This is an optional 'mouse over' title pop-up
327 title: Enter a book title here
328 # Add constraints for the field
330 # Force the length to be between 5 and 40 chars
334 # Override the default of 'Invalid input'
335 message: Length must be between 5 and 40 characters
337 # Another text field for the numeric rating
342 title: Enter a rating between 1 and 5 here
343 # Use Filter to clean up the input data
344 # Could use 'NonNumeric' below, but since Filters apply *before*
345 # constraints, it would conflict with the 'Integer' constraint below.
346 # So let's skip this and just use the constraint.
348 # Remove everything except digits
350 # Add constraints to the field
352 # Make sure it's a number
354 message: "Required. Digits only, please."
355 # Check the min & max values
359 message: "Must be between 1 and 5."
361 # Add a select list for the author selection. Note that we will
362 # dynamically fill in all the authors from the controller but we
363 # could manually set items in the select by adding this YAML code:
365 # - [ '1', 'Bastien' ]
366 # - [ '2', 'Nasseh' ]
370 # Convert the drop-down to a multi-select list
372 # Display 3 entries (user can scroll to see others)
374 # One could argue we don't need to do filters or constraints for
375 # a select list, but it's smart to do validation and sanity
376 # checks on this data in case a user "hacks" the input
377 # Add constraints to the field
379 # Make sure it's a number
387 # Global filters and constraints.
389 # The user cannot leave any fields blank
391 # If not all fields are required, move the Required constraint to the
394 # Remove whitespace at both ends
396 # Escape HTML characters for safety
399 B<NOTE:> Copying and pasting YAML from perl documentation is sometimes
400 tricky. See the L<Config::General Config for this tutorial> section of
401 this document for a more foolproof config format.
403 The main changes are:
409 The C<Select> element for C<authors> is changed from a single-select
410 drop-down to a multi-select list by adding configuration for the
411 C<multiple> and C<size> options in C<formfu_create.yml>.
415 Constraints are added to provide validation of the user input. See
416 L<HTML::FormFu::Constraint|HTML::FormFu::Constraint> for other
417 constraints that are available.
421 A variety of filters are run on every field to remove and escape
422 unwanted input. See L<HTML::FormFu::Filter|HTML::FormFu::Filter>
423 for more filter options.
428 =head2 Try Out the Updated Form
430 Press C<Ctrl-C> to kill the previous server instance (if it's still
431 running) and restart it:
433 $ script/myapp_server.pl
435 Make sure you are still logged in as C<test01> and try adding a book
436 with various errors: title less than 5 characters, non-numeric rating, a
437 rating of 0 or 6, etc. Also try selecting one, two, and zero authors.
438 When you click Submit, the HTML::FormFu C<constraint> items will
439 validate the logic and insert feedback as appropriate. Try adding blank
440 spaces at the front or the back of the title and note that it will be
444 =head1 CREATE AND UPDATE/EDIT ACTION
446 Let's expand the work done above to add an edit action. First, open
447 C<lib/MyApp/Controller/Books.pm> and add the following method to the
452 Use HTML::FormFu to update an existing book
456 sub formfu_edit :Local :FormConfig('books/formfu_create.yml') {
457 my ($self, $c, $id) = @_;
459 # Get the specified book
460 my $book = $c->model('DB::Books')->find($id);
462 # Make sure we were able to get a book
464 $c->flash->{error_msg} = "Invalid book -- Cannot edit";
465 $c->response->redirect($c->uri_for('list'));
469 # Get the form that the :FormConfig attribute saved in the stash
470 my $form = $c->stash->{form};
472 # Check if the form has been submitted (vs. displaying the initial
473 # form) and if the data passed validation. "submitted_and_valid"
474 # is shorthand for "$form->submitted && !$form->has_errors"
475 if ($form->submitted_and_valid) {
476 # Save the form data for the book
477 $form->save_to_model($book);
478 # Set a status message for the user
479 $c->flash->{status_msg} = 'Book edited';
480 # Return to the books list
481 $c->response->redirect($c->uri_for('list'));
484 # Get the authors from the DB
485 my @authorObjs = $c->model("DB::Authors")->all();
486 # Create an array of arrayrefs where each arrayref is an author
488 foreach (sort {$a->last_name cmp $b->last_name} @authorObjs) {
489 push(@authors, [$_->id, $_->last_name]);
491 # Get the select added by the config file
492 my $select = $form->get_element({type => 'Select'});
493 # Add the authors to it
494 $select->options(\@authors);
495 # Populate the form with existing values from DB
496 $form->defaults_from_model($book);
500 $c->stash->{template} = 'books/formfu_create.tt2';
503 Most of this code should look familiar to what we used in the
504 C<formfu_create> method (in fact, we should probably centralize some of
505 the common code in separate methods). The main differences are:
511 We accept C<$id> as an argument via the URL.
515 We use C<$id> to look up the existing book from the database.
519 We make sure the C<$id> and book lookup returned a valid book. If not,
520 we set the error message and return to the book list.
524 If the form has been submitted and passes validation, we skip creating a
525 new book and just use C<$form-E<gt>save_to_model> to update the existing
530 If the form is being displayed for the first time (or has failed
531 validation and it being redisplayed), we use
532 C<$form-E<gt>default_from_model> to populate the form with data from the
537 Then, edit C<root/src/books/list.tt2> and add a new link below the
538 existing "Delete" link that allows us to edit/update each existing book.
539 The last E<lt>tdE<gt> cell in the book list table should look like the
544 [% # Add a link to delete a book %]
545 <a href="[% c.uri_for('delete', book.id) %]">Delete</a>
546 [% # Add a link to edit a book %]
547 <a href="[% c.uri_for('formfu_edit', book.id) %]">Edit</a>
551 B<Note:> Only add two lines (the "Add a link to edit a book" comment
552 and the href for C<formfu_edit>). Make sure you add it below the
553 existing C<delete> link.
556 =head2 Try Out the Edit/Update Feature
558 Press C<Ctrl-C> to kill the previous server instance (if it's still
559 running) and restart it:
561 $ script/myapp_server.pl
563 Make sure you are still logged in as C<test01> and go to the
564 L<http://localhost:3000/books/list> URL in your browser. Click the
565 "Edit" link next to "Internetworking with TCP/IP Vol. II", change the
566 rating to a 3, the "II" at end of the title to the number "2", add
567 Stevens as a co-author (control-click), and click Submit. You will then
568 be returned to the book list with a "Book edited" message at the top in
569 green. Experiment with other edits to various books.
572 =head2 Config::General Config for this tutorial
574 If you are having difficulty with YAML config above, please save the
575 below into the file C<formfu_create.conf> and delete the
576 C<formfu_create.yml> file. The below is in
577 L<Config::General|Config::General> format which follows the syntax of
586 message Length must be between 5 and 40 characters
594 title Enter a book title here
605 title Enter a rating between 1 and 5 here
629 Kennedy Clark, C<hkclark@gmail.com>
631 Please report any errors, issues or suggestions to the author. The
632 most recent version of the Catalyst Tutorial can be found at
633 L<http://dev.catalyst.perl.org/repos/Catalyst/Catalyst-Manual/5.70/trunk/lib/Catalyst/Manual/Tutorial/>.
635 Copyright 20066-2008, Kennedy Clark, under Creative Commons License
636 (L<http://creativecommons.org/licenses/by-nc-sa/2.5/>).