Edit C<lib/MyApp/Controller/Books.pm> and enter the following method:
=head2 url_create
-
+
Create a book with the supplied title, rating, and author
-
+
=cut
-
+
sub url_create :Local {
# In addition to self & context, get the title, rating, &
# author_id args from the URL. Note that Catalyst automatically
# puts extra information after the "/<controller_name>/<action_name/"
# into @_. The args are separated by the '/' char on the URL.
my ($self, $c, $title, $rating, $author_id) = @_;
-
+
# Call create() on the book model object. Pass the table
# columns/field values we want to set as hash values
my $book = $c->model('DB::Book')->create({
title => $title,
rating => $rating
});
-
+
# Add a record to the join table for this book, mapping to
# appropriate author
$book->add_to_book_authors({author_id => $author_id});
# Note: Above is a shortcut for this:
# $book->create_related('book_authors', {author_id => $author_id});
-
+
# Assign the Book object to the stash for display and set template
$c->stash(book => $book,
template => 'books/create_done.tt2');
-
+
# Disable caching for this page
$c->response->header('Cache-Control' => 'no-cache');
}
[% # Not a good idea for production use, though. :-) 'Indent=1' is -%]
[% # optional, but prevents "massive indenting" of deeply nested objects -%]
[% USE Dumper(Indent=1) -%]
-
+
[% # Set the page title. META can 'go back' and set values in templates -%]
[% # that have been processed 'before' this template (here it's updating -%]
[% # the title in the root/src/wrapper.tt2 wrapper template). Note that -%]
[% # interpolation -- if you need dynamic/interpolated content in your -%]
[% # title, set "$c->stash(title => $something)" in the controller). -%]
[% META title = 'Book Created' %]
-
+
[% # Output information about the record that was added. First title. -%]
<p>Added book '[% book.title %]'
-
+
[% # Then, output the last name of the first author -%]
by '[% book.authors.first.last_name %]'
-
+
[% # Then, output the rating for the book that was added -%]
with a rating of [% book.rating %].</p>
-
+
[% # Provide a link back to the list page. 'c.uri_for' builds -%]
[% # a full URI; e.g., 'http://localhost:3000/books/list' -%]
<p><a href="[% c.uri_for('/books/list') %]">Return to list</a></p>
-
+
[% # Try out the TT Dumper (for development only!) -%]
<pre>
Dump of the 'book' variable:
browser at the C</books/list> page). You should now see the six DBIC
debug messages similar to the following (where N=1-6):
- SELECT author.id, author.first_name, author.last_name
- FROM book_author me JOIN author author
+ SELECT author.id, author.first_name, author.last_name
+ FROM book_author me JOIN author author
ON author.id = me.author_id WHERE ( me.book_id = ? ): 'N'
sub url_create :Chained('/') :PathPart('books/url_create') :Args(3) {
# In addition to self & context, get the title, rating, &
# author_id args from the URL. Note that Catalyst automatically
- # puts the first 3 arguments worth of extra information after the
+ # puts the first 3 arguments worth of extra information after the
# "/<controller_name>/<action_name/" into @_ because we specified
# "Args(3)". The args are separated by the '/' char on the URL.
my ($self, $c, $title, $rating, $author_id) = @_;
-
+
...
This converts the method to take advantage of the Chained
| /books | /books/index |
| /books/list | /books/list |
'-------------------------------------+--------------------------------------'
-
+
[debug] Loaded Chained actions:
.-------------------------------------+--------------------------------------.
| Path Spec | Private |
method:
=head2 base
-
+
Can place common logic to start chained dispatch here
-
+
=cut
-
+
sub base :Chained('/') :PathPart('books') :CaptureArgs(0) {
my ($self, $c) = @_;
-
+
# Store the ResultSet in stash so it's available for other methods
$c->stash(resultset => $c->model('DB::Book'));
-
+
# Print a message to the debug log
$c->log->debug('*** INSIDE BASE METHOD ***');
}
Here we print a log message and store the DBIC ResultSet in
-C<$c-E<gt>stash-E<gt>{resultset}> so that it's automatically available
+C<< $c->stash->{resultset} >> so that it's automatically available
for other actions that chain off C<base>. If your controller always
needs a book ID as its first argument, you could have the base method
capture that argument (with C<:CaptureArgs(1)>) and use it to pull the
-book object with C<-E<gt>find($id)> and leave it in the stash for later
+book object with C<< ->find($id) >> and leave it in the stash for later
parts of your chains to then act upon. Because we have several actions
that don't need to retrieve a book (such as the C<url_create> we are
working with now), we will instead add that functionality to a common
Edit C<lib/MyApp/Controller/Books.pm> and add the following method:
=head2 form_create
-
+
Display form to collect information for book to create
-
+
=cut
-
+
sub form_create :Chained('base') :PathPart('form_create') :Args(0) {
my ($self, $c) = @_;
-
+
# Set the TT template to use
$c->stash(template => 'books/form_create.tt2');
}
Open C<root/src/books/form_create.tt2> in your editor and enter:
[% META title = 'Manual Form Book Create' -%]
-
+
<form method="post" action="[% c.uri_for('form_create_do') %]">
<table>
<tr><td>Title:</td><td><input type="text" name="title"></td></tr>
save the form information to the database:
=head2 form_create_do
-
+
Take information from form and add to database
-
+
=cut
-
+
sub form_create_do :Chained('base') :PathPart('form_create_do') :Args(0) {
my ($self, $c) = @_;
-
+
# Retrieve the values from the form
my $title = $c->request->params->{title} || 'N/A';
my $rating = $c->request->params->{rating} || 'N/A';
my $author_id = $c->request->params->{author_id} || '1';
-
+
# Create the book
my $book = $c->model('DB::Book')->create({
title => $title,
$book->add_to_book_authors({author_id => $author_id});
# Note: Above is a shortcut for this:
# $book->create_related('book_authors', {author_id => $author_id});
-
+
# Store new model object in stash and set template
$c->stash(book => $book,
template => 'books/create_done.tt2');
header, and 2) the five lines for the Delete link near the bottom):
[% # This is a TT comment. -%]
-
+
[%- # Provide a title -%]
[% META title = 'Book List' -%]
-
+
[% # Note That the '-' at the beginning or end of TT code -%]
[% # "chomps" the whitespace/newline at that end of the -%]
[% # output (use View Source in browser to see the effect) -%]
-
+
[% # Some basic HTML with a loop to display books -%]
<table>
<tr><th>Title</th><th>Rating</th><th>Author(s)</th><th>Links</th></tr>
request).
Also notice that we are using a more advanced form of C<uri_for> than we
-have seen before. Here we use C<$c-E<gt>controller-E<gt>action_for> to
+have seen before. Here we use C<< $c->controller->action_for >> to
automatically generate a URI appropriate for that action based on the
method we want to link to while inserting the C<book.id> value into the
appropriate place. Now, if you ever change C<:PathPart('delete')> in
=item *
If you are referring to a method in the current controller, you can use
-C<$self-E<gt>action_for('_method_name_')>.
+C<< $self->action_for('_method_name_') >>.
=item *
If you are referring to a method in a different controller, you need to
include that controller's name as an argument to C<controller()>, as in
-C<$c-E<gt>controller('_controller_name_')-E<gt>action_for('_method_name_')>.
+C<< $c->controller('_controller_name_')->action_for('_method_name_') >>.
=back
add the following code:
=head2 object
-
+
Fetch the specified book object based on the book ID and store
it in the stash
-
+
=cut
-
+
sub object :Chained('base') :PathPart('id') :CaptureArgs(1) {
# $id = primary key of book to delete
my ($self, $c, $id) = @_;
-
+
# Find the book object and store it in the stash
$c->stash(object => $c->stash->{resultset}->find($id));
-
+
# Make sure the lookup was successful. You would probably
# want to do something like this in a real app:
# $c->detach('/error_404') if !$c->stash->{object};
die "Book $id not found!" if !$c->stash->{object};
-
+
# Print a message to the debug log
$c->log->debug("*** INSIDE OBJECT METHOD for obj id=$id ***");
}
Now, any other method that chains off C<object> will automatically have
-the appropriate book waiting for it in C<$c-E<gt>stash-E<gt>{object}>.
+the appropriate book waiting for it in C<< $c->stash->{object} >>.
=head2 Add a Delete Action to the Controller
following method:
=head2 delete
-
+
Delete a book
-
+
=cut
-
+
sub delete :Chained('object') :PathPart('delete') :Args(0) {
my ($self, $c) = @_;
-
+
# Use the book object saved by 'object' and delete it along
# with related 'book_author' entries
$c->stash->{object}->delete;
-
+
# Set a status message to be displayed at the top of the view
$c->stash->{status_msg} = "Book deleted.";
-
+
# Forward to the list action/method in this controller
$c->forward('list');
}
trouble.
We can improve the logic by converting to a redirect. Unlike
-C<$c-E<gt>forward('list'))> or C<$c-E<gt>detach('list'))> that perform a
+C<< $c->forward('list')) >> or C<< $c->detach('list')) >> that perform a
server-side alteration in the flow of processing, a redirect is a
client-side mechanism that causes the browser to issue an entirely new
request. As a result, the URL in the browser is updated to match the
method to match:
=head2 delete
-
+
Delete a book
-
+
=cut
-
+
sub delete :Chained('object') :PathPart('delete') :Args(0) {
my ($self, $c) = @_;
-
+
# Use the book object saved by 'object' and delete it along
# with related 'book_author' entries
$c->stash->{object}->delete;
-
+
# Set a status message to be displayed at the top of the view
$c->stash->{status_msg} = "Book deleted.";
-
+
# Redirect the user back to the list page. Note the use
# of $self->action_for as earlier in this section (BasicCRUD)
$c->response->redirect($c->uri_for($self->action_for('list')));
method to match the following:
=head2 delete
-
+
Delete a book
-
+
=cut
-
+
sub delete :Chained('object') :PathPart('delete') :Args(0) {
my ($self, $c) = @_;
-
+
# Use the book object saved by 'object' and delete it along
# with related 'book_author' entries
$c->stash->{object}->delete;
-
+
# Redirect the user back to the list page with status msg as an arg
$c->response->redirect($c->uri_for($self->action_for('list'),
{status_msg => "Book deleted."}));
Although the sample above only shows the C<content> div, leave the rest
of the file intact -- the only change we made to the C<wrapper.tt2> was
to add "C<|| c.request.params.status_msg>" to the
-C<E<lt>span class="message"E<gt>> line. Note that we definitely want
+C<< <span class="message"> >> line. Note that we definitely want
the "C<| html>" TT filter here since it would be easy for users to
modify the message on the URL and possibly inject harmful code into the
application if we left that off.
Notice in the debug log that the SQL DBIC generated has changed to
incorporate the datetime logic:
- INSERT INTO book ( created, rating, title, updated ) VALUES ( ?, ?, ?, ? ):
+ INSERT INTO book ( created, rating, title, updated ) VALUES ( ?, ?, ?, ? ):
'2010-02-16 04:18:42', '5', 'TCPIP_Illustrated_Vol-2', '2010-02-16 04:18:42'
INSERT INTO book_author ( author_id, book_id ) VALUES ( ?, ? ): '4', '10'
Then open C<lib/MyApp/Schema/ResultSet/Book.pm> and enter the following:
package MyApp::Schema::ResultSet::Book;
-
+
use strict;
use warnings;
use base 'DBIx::Class::ResultSet';
-
+
=head2 created_after
-
+
A predefined search for recently added books
-
+
=cut
-
+
sub created_after {
my ($self, $datetime) = @_;
-
+
my $date_str = $self->result_source->schema->storage
->datetime_parser->format_datetime($datetime);
-
+
return $self->search({
created => { '>' => $date_str }
});
}
-
+
1;
Then add the following method to the C<lib/MyApp/Controller/Books.pm>:
=head2 list_recent
-
+
List recently created books
-
+
=cut
-
+
sub list_recent :Chained('base') :PathPart('list_recent') :Args(1) {
my ($self, $c, $mins) = @_;
-
+
# Retrieve all of the book records as book model objects and store in the
# stash where they can be accessed by the TT template, but only
# retrieve books created within the last $min number of minutes
$c->stash(books => [$c->model('DB::Book')
->created_after(DateTime->now->subtract(minutes => $mins))]);
-
+
# Set the TT template to use. You will almost always want to do this
# in your action methods (action methods respond to user input in
# your controllers).
the following method:
=head2 list_recent_tcp
-
+
List recently created books
-
+
=cut
-
+
sub list_recent_tcp :Chained('base') :PathPart('list_recent_tcp') :Args(1) {
my ($self, $c, $mins) = @_;
-
+
# Retrieve all of the book records as book model objects and store in the
# stash where they can be accessed by the TT template, but only
# retrieve books created within the last $min number of minutes
->created_after(DateTime->now->subtract(minutes => $mins))
->search({title => {'like', '%TCP%'}})
]);
-
+
# Set the TT template to use. You will almost always want to do this
# in your action methods (action methods respond to user input in
# your controllers).
Take a look at the DBIC_TRACE output in the development server log for
the first URL and you should see something similar to the following:
- SELECT me.id, me.title, me.rating, me.created, me.updated FROM book me
+ SELECT me.id, me.title, me.rating, me.created, me.updated FROM book me
WHERE ( ( title LIKE ? AND created > ? ) ): '%TCP%', '2010-02-16 02:49:32'
However, let's not pollute our controller code with this raw "TCP" query
and add the following method:
=head2 title_like
-
+
A predefined search for books with a 'LIKE' search in the string
-
+
=cut
-
+
sub title_like {
my ($self, $title_str) = @_;
-
+
return $self->search({
title => { 'like' => "%$title_str%" }
});
We defined the search string as C<$title_str> to make the method more
flexible. Now update the C<list_recent_tcp> method in
C<lib/MyApp/Controller/Books.pm> to match the following (we have
-replaced the C<-E<gt>search> line with the C<-E<gt>title_like> line
+replaced the C<< ->search >> line with the C<< ->title_like >> line
shown here -- the rest of the method should be the same):
=head2 list_recent_tcp
-
+
List recently created books
-
+
=cut
-
+
sub list_recent_tcp :Chained('base') :PathPart('list_recent_tcp') :Args(1) {
my ($self, $c, $mins) = @_;
-
+
# Retrieve all of the book records as book model objects and store in the
# stash where they can be accessed by the TT template, but only
# retrieve books created within the last $min number of minutes
->created_after(DateTime->now->subtract(minutes => $mins))
->title_like('TCP')
]);
-
+
# Set the TT template to use. You will almost always want to do this
# in your action methods (action methods respond to user input in
# your controllers).
#
sub full_name {
my ($self) = @_;
-
+
return $self->first_name . ' ' . $self->last_name;
}
C<lib/MyApp/Schema/Result/Book.pm> and add the following method:
=head2 author_count
-
+
Return the number of authors for the current book
-
+
=cut
-
+
sub author_count {
my ($self) = @_;
-
+
# Use the 'many_to_many' relationship to fetch all of the authors for the current
# and the 'count' method in DBIx::Class::ResultSet to get a SQL COUNT
return $self->authors->count;
same C<lib/MyApp/Schema/Result/Book.pm> file:
=head2 author_list
-
+
Return a comma-separated list of authors for the current book
-
+
=cut
-
+
sub author_list {
my ($self) = @_;
-
- # Loop through all authors for the current book, calling all the 'full_name'
+
+ # Loop through all authors for the current book, calling all the 'full_name'
# Result Class method for each
my @names;
foreach my $author ($self->authors) {
push(@names, $author->full_name);
}
-
+
return join(', ', @names);
}