=head2 Include a Create Action in the Books Controller
-Edit C<lib/MyApp/Controller/Books.pm> and enter the following method:
+Edit F<lib/MyApp/Controller/Books.pm> and enter the following method:
=head2 url_create
Also note that we are explicitly setting a C<no-cache> "Cache-Control"
header to force browsers using the page to get a fresh copy every time.
You could even move this to a C<auto> method in
-C<lib/MyApp/Controller/Root.pm> and it would automatically get applied
+F<lib/MyApp/Controller/Root.pm> and it would automatically get applied
to every page in the whole application via a single line of code
(remember from Chapter 3, that every C<auto> method gets run in the
Controller hierarchy).
=head2 Include a Template for the 'url_create' Action:
-Edit C<root/src/books/create_done.tt2> and then enter:
+Edit F<root/src/books/create_done.tt2> and then enter:
[% # Use the TT Dumper plugin to Data::Dumper variables to the browser -%]
[% # Not a good idea for production use, though. :-) 'Indent=1' is -%]
method that we saw in the previous chapter of the tutorial, there is an
alternate approach that allows us to be more specific while also paving
the way for more advanced capabilities. Change the method declaration
-for C<url_create> in C<lib/MyApp/Controller/Books.pm> you entered above
+for C<url_create> in F<lib/MyApp/Controller/Books.pm> you entered above
to match the following:
sub url_create :Chained('/') :PathPart('books/url_create') :Args(3) {
Let's make a quick update to our initial Chained action to show a little
more of the power of chaining. First, open
-C<lib/MyApp/Controller/Books.pm> in your editor and add the following
+F<lib/MyApp/Controller/Books.pm> in your editor and add the following
method:
=head2 base
C<object> action shortly.
As for C<url_create>, let's modify it to first dispatch to C<base>.
-Open up C<lib/MyApp/Controller/Books.pm> and edit the declaration for
+Open up F<lib/MyApp/Controller/Books.pm> and edit the declaration for
C<url_create> to match the following:
sub url_create :Chained('base') :PathPart('url_create') :Args(3) {
-Once you save C<lib/MyApp/Controller/Books.pm>, notice that the
+Once you save F<lib/MyApp/Controller/Books.pm>, notice that the
development server will restart and our "Loaded Chained actions" section
will changed slightly:
"create" actions more than once. Don't worry about it as long as the
number of books is appropriate for the number of times you added new
books... there should be the original five books added via
-C<myapp01.sql> plus one additional book for each time you ran one of the
+F<myapp01.sql> plus one additional book for each time you ran one of the
url_create variations above.)
=head2 Add Method to Display The Form
-Edit C<lib/MyApp/Controller/Books.pm> and add the following method:
+Edit F<lib/MyApp/Controller/Books.pm> and add the following method:
=head2 form_create
=head2 Add a Template for the Form
-Open C<root/src/books/form_create.tt2> in your editor and enter:
+Open F<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>
- <tr><td>Rating:</td><td><input type="text" name="rating"></td></tr>
- <tr><td>Author ID:</td><td><input type="text" name="author_id"></td></tr>
+ <tr><td>Title:</td><td><input type="text" name="title"></td></tr>
+ <tr><td>Rating:</td><td><input type="text" name="rating"></td></tr>
+ <tr><td>Author ID:</td><td><input type="text" name="author_id"></td></tr>
</table>
<input type="submit" name="Submit" value="Submit">
</form>
=head2 Add a Method to Process Form Values and Update Database
-Edit C<lib/MyApp/Controller/Books.pm> and add the following method to
+Edit F<lib/MyApp/Controller/Books.pm> and add the following method to
save the form information to the database:
=head2 form_create_do
Point your browser to L<http://localhost:3000/books/form_create> and
enter "TCP/IP Illustrated, Vol 3" for the title, a rating of 5, and an
author ID of 4. You should then see the output of the same
-C<create_done.tt2> template seen in earlier examples. Finally, click
+F<create_done.tt2> template seen in earlier examples. Finally, click
"Return to list" to view the full list of books.
B<Note:> Having the user enter the primary key ID for the author is
=head2 Include a Delete Link in the List
-Edit C<root/src/books/list.tt2> and update it to match the following
+Edit F<root/src/books/list.tt2> and update it to match the following
(two sections have changed: 1) the additional '<th>Links</th>' table
header, and 2) the five lines for the Delete link near the bottom):
<tr><th>Title</th><th>Rating</th><th>Author(s)</th><th>Links</th></tr>
[% # Display each book in a table row %]
[% FOREACH book IN books -%]
- <tr>
- <td>[% book.title %]</td>
- <td>[% book.rating %]</td>
- <td>
- [% # NOTE: See Chapter 4 for a better way to do this! -%]
- [% # First initialize a TT variable to hold a list. Then use a TT FOREACH -%]
- [% # loop in 'side effect notation' to load just the last names of the -%]
- [% # authors into the list. Note that the 'push' TT vmethod doesn't return -%]
- [% # a value, so nothing will be printed here. But, if you have something -%]
- [% # in TT that does return a value and you don't want it printed, you -%]
- [% # 1) assign it to a bogus value, or -%]
- [% # 2) use the CALL keyword to call it and discard the return value. -%]
- [% tt_authors = [ ];
- tt_authors.push(author.last_name) FOREACH author = book.authors %]
- [% # Now use a TT 'virtual method' to display the author count in parens -%]
- [% # Note the use of the TT filter "| html" to escape dangerous characters -%]
- ([% tt_authors.size | html %])
- [% # Use another TT vmethod to join & print the names & comma separators -%]
- [% tt_authors.join(', ') | html %]
- </td>
- <td>
- [% # Add a link to delete a book %]
- <a href="[%
- c.uri_for(c.controller.action_for('delete'), [book.id]) %]">Delete</a>
- </td>
- </tr>
+ <tr>
+ <td>[% book.title %]</td>
+ <td>[% book.rating %]</td>
+ <td>
+ [% # NOTE: See Chapter 4 for a better way to do this! -%]
+ [% # First initialize a TT variable to hold a list. Then use a TT FOREACH -%]
+ [% # loop in 'side effect notation' to load just the last names of the -%]
+ [% # authors into the list. Note that the 'push' TT vmethod doesn't return -%]
+ [% # a value, so nothing will be printed here. But, if you have something -%]
+ [% # in TT that does return a value and you don't want it printed, you -%]
+ [% # 1) assign it to a bogus value, or -%]
+ [% # 2) use the CALL keyword to call it and discard the return value. -%]
+ [% tt_authors = [ ];
+ tt_authors.push(author.last_name) FOREACH author = book.authors %]
+ [% # Now use a TT 'virtual method' to display the author count in parens -%]
+ [% # Note the use of the TT filter "| html" to escape dangerous characters -%]
+ ([% tt_authors.size | html %])
+ [% # Use another TT vmethod to join & print the names & comma separators -%]
+ [% tt_authors.join(', ') | html %]
+ </td>
+ <td>
+ [% # Add a link to delete a book %]
+ <a href="[%
+ c.uri_for(c.controller.action_for('delete'), [book.id]) %]">Delete</a>
+ </td>
+ </tr>
[% END -%]
</table>
C<url_create> that don't operate on an existing book can chain directly
off base.
-To add the C<object> method, edit C<lib/MyApp/Controller/Books.pm> and
+To add the C<object> method, edit F<lib/MyApp/Controller/Books.pm> and
add the following code:
=head2 object
=head2 Add a Delete Action to the Controller
-Open C<lib/MyApp/Controller/Books.pm> in your editor and add the
+Open F<lib/MyApp/Controller/Books.pm> in your editor and add the
following method:
=head2 delete
destination of the redirection URL.
To convert the forward used in the previous section to a redirect, open
-C<lib/MyApp/Controller/Books.pm> and edit the existing C<sub delete>
+F<lib/MyApp/Controller/Books.pm> and edit the existing C<sub delete>
method to match:
=head2 delete
L<Chapter 5|Catalyst::Manual::Tutorial::05_Authentication> of this
tutorial; however, here we will pass the information via query
parameters on the redirect itself. Open
-C<lib/MyApp/Controller/Books.pm> and update the existing C<sub delete>
+F<lib/MyApp/Controller/Books.pm> and update the existing C<sub delete>
method to match the following:
=head2 delete
This modification simply leverages the ability of C<uri_for> to include
an arbitrary number of name/value pairs in a hash reference. Next, we
-need to update C<root/src/wrapper.tt2> to handle C<status_msg> as a
+need to update F<root/src/wrapper.tt2> to handle C<status_msg> as a
query parameter:
...
...
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
+of the file intact -- the only change we made to the F<wrapper.tt2> was
to add "C<|| c.request.params.status_msg>" to the
C<< <span class="message"> >> line. Note that we definitely want
the "C<| html>" TT filter here since it would be easy for users to
include the L<DBIx::Class::TimeStamp> in the C<load_components> line of
the Result Classes.
-If you open C<lib/MyApp/Schema/Result/Book.pm> in your editor you should
+If you open F<lib/MyApp/Schema/Result/Book.pm> in your editor you should
see that the C<created> and C<updated> fields are now included in the
call to C<add_columns()>. However, also notice that the C<many_to_many>
relationships we manually added below the "C<# DO NOT MODIFY...>" line
were automatically preserved.
-While we C<lib/MyApp/Schema/Result/Book.pm> open, let's update it with
+While we F<lib/MyApp/Schema/Result/Book.pm> open, let's update it with
some additional information to have DBIC automatically handle the
updating of these two fields for us. Insert the following code at the
bottom of the file (it B<must> be B<below> the "C<# DO NOT MODIFY...>"
B<Note> that adding the lines above will cause the development server to
automatically restart if you are running it with the "-r" option. In
other words, the development server is smart enough to restart not only
-for code under the C<MyApp/Controller/>, C<MyApp/Model/>, and
-C<MyApp/View/> directories, but also under other directions such as our
-"external DBIC model" in C<MyApp/Schema/>. However, also note that it's
+for code under the F<MyApp/Controller/>, F<MyApp/Model/>, and
+F<MyApp/View/> directories, but also under other directions such as our
+"external DBIC model" in F<MyApp/Schema/>. However, also note that it's
smart enough to B<not> restart when you edit your C<.tt2> files under
-C<root/>.
+F<root/>.
Then enter the following URL into your web browser:
=head2 Create a ResultSet Class
An often overlooked but extremely powerful features of DBIC is that it
-allows you to supply your own subclasses of C<DBIx::Class::ResultSet>.
+allows you to supply your own subclasses of L<DBIx::Class::ResultSet>.
This can be used to pull complex and unsightly "query code" out of your
controllers and encapsulate it in a method of your ResultSet Class.
These "canned queries" in your ResultSet Class can then be invoked via a
$ mkdir lib/MyApp/Schema/ResultSet
-Then open C<lib/MyApp/Schema/ResultSet/Book.pm> and enter the following:
+Then open F<lib/MyApp/Schema/ResultSet/Book.pm> and enter the following:
package MyApp::Schema::ResultSet::Book;
1;
-Then add the following method to the C<lib/MyApp/Controller/Books.pm>:
+Then add the following method to the F<lib/MyApp/Controller/Books.pm>:
=head2 list_recent
=head2 Chaining ResultSets
-One of the most helpful and powerful features in C<DBIx::Class> is that
+One of the most helpful and powerful features in L<DBIx::Class> is that
it allows you to "chain together" a series of queries (note that this
has nothing to do with the "Chained Dispatch" for Catalyst that we were
discussing earlier). Because each ResultSet method returns another
implemented in the previous section for our "canned search", we can
combine the two capabilities. For example, let's add an action to our
C<Books> controller that lists books that are both recent I<and> have
-"TCP" in the title. Open up C<lib/MyApp/Controller/Books.pm> and add
+"TCP" in the title. Open up F<lib/MyApp/Controller/Books.pm> and add
the following method:
=head2 list_recent_tcp
However, let's not pollute our controller code with this raw "TCP" query
-- it would be cleaner to encapsulate that code in a method on our
-ResultSet Class. To do this, open C<lib/MyApp/Schema/ResultSet/Book.pm>
+ResultSet Class. To do this, open F<lib/MyApp/Schema/ResultSet/Book.pm>
and add the following method:
=head2 title_like
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
+F<lib/MyApp/Controller/Books.pm> to match the following (we have
replaced the C<< ->search >> line with the C<< ->title_like >> line
shown here -- the rest of the method should be the same):
Whereas the ResultSet construct is used in DBIC to correspond to an
entire query, the Result Class construct is used to represent a row.
Therefore, we can add row-specific "helper methods" to our Result
-Classes stored in C<lib/MyApp/Schema/Result/>. For example, open
-C<lib/MyApp/Schema/Result/Author.pm> and add the following method (as
+Classes stored in F<lib/MyApp/Schema/Result/>. For example, open
+F<lib/MyApp/Schema/Result/Author.pm> and add the following method (as
always, it must be above the closing "C<1;>"):
#
}
This will allow us to conveniently retrieve both the first and last name
-for an author in one shot. Now open C<root/src/books/list.tt2> and
+for an author in one shot. Now open F<root/src/books/list.tt2> and
change the definition of C<tt_authors> from this:
...
The previous section illustrated how we could use a Result Class method
to print the full names of the authors without adding any extra code to
our view, but it still left us with a fairly ugly mess (see
-C<root/src/books/list.tt2>):
+F<root/src/books/list.tt2>):
...
<td>
- [% # NOTE: See Chapter 4 for a better way to do this! -%]
- [% # First initialize a TT variable to hold a list. Then use a TT FOREACH -%]
- [% # loop in 'side effect notation' to load just the last names of the -%]
- [% # authors into the list. Note that the 'push' TT vmethod does not print -%]
- [% # a value, so nothing will be printed here. But, if you have something -%]
- [% # in TT that does return a method and you don't want it printed, you -%]
- [% # can: 1) assign it to a bogus value, or 2) use the CALL keyword to -%]
- [% # call it and discard the return value. -%]
- [% tt_authors = [ ];
- tt_authors.push(author.full_name) FOREACH author = book.authors %]
- [% # Now use a TT 'virtual method' to display the author count in parens -%]
- [% # Note the use of the TT filter "| html" to escape dangerous characters -%]
- ([% tt_authors.size | html %])
- [% # Use another TT vmethod to join & print the names & comma separators -%]
- [% tt_authors.join(', ') | html %]
+ [% # NOTE: See Chapter 4 for a better way to do this! -%]
+ [% # First initialize a TT variable to hold a list. Then use a TT FOREACH -%]
+ [% # loop in 'side effect notation' to load just the last names of the -%]
+ [% # authors into the list. Note that the 'push' TT vmethod does not print -%]
+ [% # a value, so nothing will be printed here. But, if you have something -%]
+ [% # in TT that does return a method and you don't want it printed, you -%]
+ [% # can: 1) assign it to a bogus value, or 2) use the CALL keyword to -%]
+ [% # call it and discard the return value. -%]
+ [% tt_authors = [ ];
+ tt_authors.push(author.full_name) FOREACH author = book.authors %]
+ [% # Now use a TT 'virtual method' to display the author count in parens -%]
+ [% # Note the use of the TT filter "| html" to escape dangerous characters -%]
+ ([% tt_authors.size | html %])
+ [% # Use another TT vmethod to join & print the names & comma separators -%]
+ [% tt_authors.join(', ') | html %]
</td>
...
Let's combine some of the techniques used earlier in this section to
clean this up. First, let's add a method to our Book Result Class to
return the number of authors for a book. Open
-C<lib/MyApp/Schema/Result/Book.pm> and add the following method:
+F<lib/MyApp/Schema/Result/Book.pm> and add the following method:
=head2 author_count
}
Next, let's add a method to return a list of authors for a book to the
-same C<lib/MyApp/Schema/Result/Book.pm> file:
+same F<lib/MyApp/Schema/Result/Book.pm> file:
=head2 author_list
}
This method loops through each author, using the C<full_name> Result
-Class method we added to C<lib/MyApp/Schema/Result/Author.pm> in the
+Class method we added to F<lib/MyApp/Schema/Result/Author.pm> in the
prior section.
Using these two methods, we can simplify our TT code. Open
-C<root/src/books/list.tt2> and update the "Author(s)" table cell to
+F<root/src/books/list.tt2> and update the "Author(s)" table cell to
match the following:
...
<td>
- [% # Print count and author list using Result Class methods -%]
- ([% book.author_count | html %]) [% book.author_list | html %]
+ [% # Print count and author list using Result Class methods -%]
+ ([% book.author_count | html %]) [% book.author_list | html %]
</td>
...