NAME

Catalyst::Manual::Tutorial::Appendices - Catalyst Tutorial - Part 10: Appendices

OVERVIEW

This is Part 10 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. Advanced CRUD

  10. Appendices

DESCRIPTION

This part of the tutorial provides supporting information relevant to the Catalyst tutorial.

APPENDIX 1: CUT AND PASTE FOR POD-BASED EXAMPLES

You may notice that Pod indents example code with four spaces. This section provides some quick advice to "un-indent" this text in common editors.

"Un-indenting" with Vi/Vim

When cutting and pasting multi-line text from Pod-based documents, the following vi/vim regexs can be helpful to "un-indent" the inserted text (do NOT type the quotes, they are only included to show spaces in the regex patterns). Note that all 3 of the regexs end in 4 spaces:

  • ":0,$s/^ "

    Removes four leading spaces from the entire file (from the first line, 0, to the last line, $).

  • "%s/^ "

    A shortcut for the previous item (% specifies the entire file; so this removes four leading spaces from every line).

  • ":.,$s/^ "

    Removes the first four spaces from the line the cursor is on at the time the regex command is executed (".") to the last line of the file.

  • ":.,44s/^ "

    Removes four leading space from the current line through line 44 (obviously adjust the 44 to the appropriate value in your example).

"Un-indenting" with Emacs

Although there author has not used Emacs for many years (apologies to the Emacs fans out there), here is a quick hint to get you started. To replace the leading spaces of every line in a file, use:

M-x replace-regexp<RET>
Replace regexp: ^    <RET>
with: <RET>

All of that will occur on the single line at the bottom of your screen. Note that "<RET>" represents the return key/enter. Also, there are four spaces after the "^" on the "Replace regexp:" line and no spaces entered on the last line.

You can limit the replacement operation by selecting text first (depending on your version of Emacs, you can either use the mouse or experiment with commands such as C-SPC to set the mark at the cursor location and C-< and C-> to set the mark at the beginning and end of the file respectively.

APPENDIX 2: USING MYSQL AND POSTGRESQL

The main database used in this tutorial is the very simple yet powerful SQLite. This section provides information that can be used to "convert" the tutorial to use MySQL and PostgreSQL. However, note that part of the beauty of the MVC architecture is that very little database-specific code is spread throughout the system (at least when MVC is "done right"). Consequently, converting from one database to another is relatively painless with most Catalyst applications. In general, you just need to adapt the schema definition .sql file you use to initialize your database and adjust a few configuration parameters.

Also note that the purpose of the data definition statements for this section are not designed to take maximum advantage of the various features in each database for issues such as referential integrity and field types/constraints.

MySQL

Use the following steps to adapt the tutorial to MySQL. Thanks to Jim Howard for the help.

  • Part 2: Catalyst Basics

    • Install the required software:

      • The MySQL database server and client utility.

      • The Perl DBD::MySQL module

      For CentOS users (see Catalyst::Manual::Installation::CentOS4), you can use the following commands to install the software and start the MySQL daemon:

      yum -y install mysql mysql-server
      service mysqld start
    • Create the database and set the permissions:

      $ mysql
      Welcome to the MySQL monitor.  Commands end with ; or \g.
      Your MySQL connection id is 2 to server version: 4.1.20
      
      Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
      
      mysql> create database myapp;
      Query OK, 1 row affected (0.01 sec)
      
      mysql> grant all on myapp.* to tutorial@'localhost';
      Query OK, 0 rows affected (0.00 sec)
      
      mysql> flush privileges;
      Query OK, 0 rows affected (0.00 sec)
      
      mysql> quit
      Bye
    • Create the .sql file and load the data:

      • Open the myapp01_mysql.sql in your editor and enter:

        --
        -- Create a very simple database to hold book and author information
        --
        DROP TABLE IF EXISTS books;
        DROP TABLE IF EXISTS book_authors;
        DROP TABLE IF EXISTS authors;
        CREATE TABLE books (
               id          INT(11) PRIMARY KEY AUTO_INCREMENT,
               title       TEXT ,
               rating      INT(11)
        );
        -- 'book_authors' is a many-to-many join table between books & authors
        CREATE TABLE book_authors (
               book_id     INT(11),
               author_id   INT(11),
               PRIMARY KEY (book_id, author_id)
        );
        CREATE TABLE authors (
               id          INT(11) PRIMARY KEY AUTO_INCREMENT,
               first_name  TEXT,
               last_name   TEXT
        );
        ---
        --- Load some sample data
        ---
        INSERT INTO books VALUES (1, 'CCSP SNRS Exam Certification Guide', 5);
        INSERT INTO books VALUES (2, 'TCP/IP Illustrated, Volume 1', 5);
        INSERT INTO books VALUES (3, 'Internetworking with TCP/IP Vol.1', 4);
        INSERT INTO books VALUES (4, 'Perl Cookbook', 5);
        INSERT INTO books VALUES (5, 'Designing with Web Standards', 5);
        INSERT INTO authors VALUES (1, 'Greg', 'Bastien');
        INSERT INTO authors VALUES (2, 'Sara', 'Nasseh');
        INSERT INTO authors VALUES (3, 'Christian', 'Degu');
        INSERT INTO authors VALUES (4, 'Richard', 'Stevens');
        INSERT INTO authors VALUES (5, 'Douglas', 'Comer');
        INSERT INTO authors VALUES (6, 'Tom', 'Christiansen');
        INSERT INTO authors VALUES (7, ' Nathan', 'Torkington');
        INSERT INTO authors VALUES (8, 'Jeffrey', 'Zeldman');
        INSERT INTO book_authors VALUES (1, 1);
        INSERT INTO book_authors VALUES (1, 2);
        INSERT INTO book_authors VALUES (1, 3);
        INSERT INTO book_authors VALUES (2, 4);
        INSERT INTO book_authors VALUES (3, 5);
        INSERT INTO book_authors VALUES (4, 6);
        INSERT INTO book_authors VALUES (4, 7);
        INSERT INTO book_authors VALUES (5, 8);
      • Load the data:

        mysql -ututorial myapp < myapp01_mysql.sql
      • Make sure the data loaded correctly:

        $ mysql -ututorial myapp
        Reading table information for completion of table and column names
        You can turn off this feature to get a quicker startup with -A
        
        Welcome to the MySQL monitor.  Commands end with ; or \g.
        Your MySQL connection id is 4 to server version: 4.1.20
        
        Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
        
        mysql> show tables;
        +-----------------+
        | Tables_in_myapp |
        +-----------------+
        | authors         |
        | book_authors    |
        | books           |
        +-----------------+
        3 rows in set (0.00 sec)
        
        mysql> select * from books;
        +----+------------------------------------+--------+
        | id | title                              | rating |
        +----+------------------------------------+--------+
        |  1 | CCSP SNRS Exam Certification Guide |      5 |
        |  2 | TCP/IP Illustrated, Volume 1       |      5 |
        |  3 | Internetworking with TCP/IP Vol.1  |      4 |
        |  4 | Perl Cookbook                      |      5 |
        |  5 | Designing with Web Standards       |      5 |
        +----+------------------------------------+--------+
        5 rows in set (0.00 sec)
        
        mysql>
    • Update the model:

      • Delete the existing model:

        rm lib/MyApp/Model/MyAppDB.pm
      • Regenerate the model using the Catalyst "_create.pl" script:

        script/myapp_create.pl model MyAppDB DBIC::Schema MyApp::Schema \
            dbi:mysql:myapp '_username_here_' '_password_here_' '{ AutoCommit => 1 }'
  • Part 4: Authentication

    • Create the .sql file for the user/roles data:

      Open myapp02_mysql.sql in your editor and enter:

      --
      -- Add users and roles tables, along with a many-to-many join table
      --
      CREATE TABLE users (
              id            INT(11) PRIMARY KEY,
              username      TEXT,
              password      TEXT,
              email_address TEXT,
              first_name    TEXT,
              last_name     TEXT,
              active        INT(11)
      );
      CREATE TABLE roles (
              id   INTEGER PRIMARY KEY,
              role TEXT
      );
      CREATE TABLE user_roles (
              user_id INT(11),
              role_id INT(11),
              PRIMARY KEY (user_id, role_id)
      );
      --
      -- Load up some initial test data
      --
      INSERT INTO users VALUES (1, 'test01', 'mypass', 't01@na.com', 'Joe',  'Blow', 1);
      INSERT INTO users VALUES (2, 'test02', 'mypass', 't02@na.com', 'Jane', 'Doe',  1);
      INSERT INTO users VALUES (3, 'test03', 'mypass', 't03@na.com', 'No',   'Go',   0);
      INSERT INTO roles VALUES (1, 'user');
      INSERT INTO roles VALUES (2, 'admin');
      INSERT INTO user_roles VALUES (1, 1);
      INSERT INTO user_roles VALUES (1, 2);
      INSERT INTO user_roles VALUES (2, 1);
      INSERT INTO user_roles VALUES (3, 1);
    • Load the user/roles data:

      mysql -ututorial myapp < myapp02_mysql.sql
    • Create the .sql file for the hashed password data:

      Open myapp03_mysql.sql in your editor and enter:

      --
      -- Convert passwords to SHA-1 hashes
      --
      UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 1;
      UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 2;
      UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 3;
    • Load the user/roles data:

      mysql -ututorial myapp < myapp03_mysql.sql

PostgreSQL

Use the following steps to adapt the tutorial to PostgreSQL. Thanks to Louis Moore for the help who was in turn helped by Marcello Romani and Tom Lanyon.

  • Part 2: Catalyst Basics

    • Install the required software:

      • The PostgreSQL database server and client.

      • The Perl DBD::Pg module

    • Create the database and a user for the database

      $ createuser -P catappuser
      Enter password for new role: <catalyst>
      Enter it again: <catalyst>
      Shall the new role be a superuser? (y/n) n
      Shall the new role be allowed to create databases? (y/n) n
      Shall the new role be allowed to create more new roles? (y/n) n
      CREATE ROLE
      $ createdb -O catappuser catappdb
      CREATE DATABASE
    • Create the .sql file and load the data:

      • Open the myapp01_psql.sql in your editor and enter:

        --
        -- Create a very simple database to hold book and author information
        --
        -- The sequence is how we get a unique id in PostgreSQL
        --
        CREATE SEQUENCE books_seq START 5 ;
        SELECT nextval ('books_seq');
        
        CREATE TABLE books (
           id          INTEGER PRIMARY KEY DEFAULT nextval('books_seq'),
           title       TEXT ,
           rating      INTEGER
           );
        
        -- 'book_authors' is a many-to-many join table between books & authors
        CREATE TABLE book_authors (
           book_id     INTEGER,
           author_id   INTEGER,
           PRIMARY KEY (book_id, author_id)
           );
        
        CREATE SEQUENCE authors_seq START 8 ;
        SELECT nextval ('authors_seq');
        
        CREATE TABLE authors (
        id          INTEGER PRIMARY KEY DEFAULT nextval('authors_seq'),
        first_name  TEXT,
        last_name   TEXT
        );
        ---
        --- Load some sample data
        ---
        INSERT INTO books VALUES (1, 'CCSP SNRS Exam Certification Guide', 5);
        INSERT INTO books VALUES (2, 'TCP/IP Illustrated, Volume 1', 5);
        INSERT INTO books VALUES (3, 'Internetworking with TCP/IP Vol.1', 4);
        INSERT INTO books VALUES (4, 'Perl Cookbook', 5);
        INSERT INTO books VALUES (5, 'Designing with Web Standards', 5);
        INSERT INTO authors VALUES (1, 'Greg', 'Bastien');
        INSERT INTO authors VALUES (2, 'Sara', 'Nasseh');
        INSERT INTO authors VALUES (3, 'Christian', 'Degu');
        INSERT INTO authors VALUES (4, 'Richard', 'Stevens');
        INSERT INTO authors VALUES (5, 'Douglas', 'Comer');
        INSERT INTO authors VALUES (6, 'Tom', 'Christiansen');
        INSERT INTO authors VALUES (7, 'Nathan', 'Torkington');
        INSERT INTO authors VALUES (8, 'Jeffrey', 'Zeldman');
        INSERT INTO book_authors VALUES (1, 1);
        INSERT INTO book_authors VALUES (1, 2);
        INSERT INTO book_authors VALUES (1, 3);
        INSERT INTO book_authors VALUES (2, 4);
        INSERT INTO book_authors VALUES (3, 5);
        INSERT INTO book_authors VALUES (4, 6);
        INSERT INTO book_authors VALUES (4, 7);
        INSERT INTO book_authors VALUES (5, 8);
      • Load the data:

        $ psql -U catappuser -W catappdb
        Password for user catappuser: <catalyst>
        Welcome to psql 8.1.8, the PostgreSQL interactive terminal.
        
        Type:  \copyright for distribution terms
               \h for help with SQL commands
               \? for help with psql commands
               \g or terminate with semicolon to execute query
               \q to quit
        
        catappdb=> \i myapp01_psql.sql
        
        CREATE SEQUENCE
        nextval
        ---------
               5
        (1 row)
        
        psql:myapp01_psql.sql:11: NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "books_pkey" for table "books"
        CREATE TABLE
        psql:myapp01_psql.sql:19: NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "book_authors_pkey" for table
        "book_authors"
        CREATE TABLE
        CREATE SEQUENCE
         nextval
        ---------
              8
        (1 row)
        
        psql:myapp01_psql.sql:30: NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "authors_pkey" for table "authors"
        CREATE TABLE
        INSERT 0 1
        INSERT 0 1
        INSERT 0 1
        INSERT 0 1
        ...
      • Make sure the data loaded correctly:

        catappdb=> \dt
                    List of relations
         Schema |     Name     | Type  |  Owner
        --------+--------------+-------+----------
         public | authors      | table | catappuser
         public | book_authors | table | catappuser
         public | books        | table | catappuser
        (3 rows)
        
        catappdb=> select * from books;
         id |               title                | rating
        ----+------------------------------------+--------
          1 | CCSP SNRS Exam Certification Guide |      5
          2 | TCP/IP Illustrated, Volume 1       |      5
          3 | Internetworking with TCP/IP Vol.1  |      4
          4 | Perl Cookbook                      |      5
          5 | Designing with Web Standards       |      5
         (5 rows)
        
        catappdb=> \q
    • After the steps where you:

      edit lib/MyApp.pm
      
      create lib/MyAppDB.pm
      
      create lib/MyAppDB/Book.pm
      
      create lib/MyAppDB/Author.pm
      
      create lib/MyAppDB/BookAuthor.pm
    • Generate the model using the Catalyst "_create.pl" script:

      script/myapp_create.pl model MyAppDB DBIC::Schema MyAppDB 'dbi:Pg:dbname=catappdb' 'catappuser' 'catalyst' '{ AutoCommit => 1 }'
  • Part 4: Authentication

    • Create the .sql file for the user/roles data:

      Open myapp02_psql.sql in your editor and enter:

      --
      -- Add users and roles tables, along with a many-to-many join table
      --
      
      CREATE SEQUENCE users_seq START 3 ;
      SELECT nextval ('users_seq');
      
      CREATE TABLE users (
              id            INTEGER PRIMARY KEY DEFAULT nextval('users_seq'),
              username      TEXT,
              password      TEXT,
              email_address TEXT,
              first_name    TEXT,
              last_name     TEXT,
              active        INTEGER
      );
      
      CREATE SEQUENCE roles_seq START 2 ;
      SELECT nextval ('roles_seq');
      
      CREATE TABLE roles (
              id   INTEGER PRIMARY KEY DEFAULT nextval('roles_seq'),
              role TEXT
      );
      
      CREATE TABLE user_roles (
              user_id INTEGER,
              role_id INTEGER,
              PRIMARY KEY (user_id, role_id)
      );
      
      --
      -- Load up some initial test data
      --
      INSERT INTO users VALUES (1, 'test01', 'mypass', 't01@na.com', 'Joe',  'Blow', 1);
      INSERT INTO users VALUES (2, 'test02', 'mypass', 't02@na.com', 'Jane', 'Doe',  1);
      INSERT INTO users VALUES (3, 'test03', 'mypass', 't03@na.com', 'No',   'Go',   0);
      INSERT INTO roles VALUES (1, 'user');
      INSERT INTO roles VALUES (2, 'admin');
      INSERT INTO user_roles VALUES (1, 1);
      INSERT INTO user_roles VALUES (1, 2);
      INSERT INTO user_roles VALUES (2, 1);
      INSERT INTO user_roles VALUES (3, 1);
    • Load the data:

      $ psql -U catappuser -W catappdb
      Password for user catappuser: catalyst
      Welcome to psql 8.1.8, the PostgreSQL interactive terminal.
      
      Type:  \copyright for distribution terms
             \h for help with SQL commands
             \? for help with psql commands
             \g or terminate with semicolon to execute query
             \q to quit
      
      catappdb=> \i myapp02_psql.sql
      
      CREATE SEQUENCE
       nextval
      ---------
             3
      (1 row)
      
      psql:myapp02_psql.sql:16: NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "users_pkey" for table "users"
      CREATE TABLE
      CREATE SEQUENCE
       nextval
      ---------
             2
      (1 row)
      
      psql:myapp02_psql.sql:24: NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "roles_pkey" for table "roles"
      CREATE TABLE
      psql:myapp02_psql.sql:30: NOTICE:  CREATE TABLE / PRIMARY KEY will create implicit index "user_roles_pkey" for table "user_roles"
      CREATE TABLE
      INSERT 0 1
      INSERT 0 1
      INSERT 0 1
      INSERT 0 1
      INSERT 0 1
      INSERT 0 1
      INSERT 0 1
      INSERT 0 1
      INSERT 0 1
      catappdb=>
      
      catappdb=> select * from users;
       id | username | password | email_address | first_name | last_name | active
      ----+----------+----------+---------------+------------+-----------+--------
        1 | test01   | mypass   | t01@na.com    | Joe        | Blow      |      1
        2 | test02   | mypass   | t02@na.com    | Jane       | Doe       |      1
        3 | test03   | mypass   | t03@na.com    | No         | Go        |      0
      (3 rows)
    • Create the .sql file for the hashed password data:

      Open myapp03_psql.sql in your editor and enter:

      --
      -- Convert passwords to SHA-1 hashes
      --
      UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 1;
      UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 2;
      UPDATE users SET password = 'e727d1464ae12436e899a726da5b2f11d8381b26' WHERE id = 3;
    • Load in the data

      $ psql -U catappuser -W catappdb
      Password for user catappuser:
      Welcome to psql 8.1.8, the PostgreSQL interactive terminal.
      
      Type:  \copyright for distribution terms
             \h for help with SQL commands
             \? for help with psql commands
             \g or terminate with semicolon to execute query
             \q to quit
      
      catappdb=> \i myapp03_psql.sql
      UPDATE 1
      UPDATE 1
      UPDATE 1

APPENDIX 3: IMPROVED HASHING SCRIPT

Here is an improved SHA-1 hashing script from Gavin Henry that does not expose the passwords to "capture" on the command line.

#!/usr/bin/perl -w
#===============================================================================
#
#         FILE:  enc_pass.pl
#
#        USAGE:  ./enc_pass.pl
#
#  DESCRIPTION:  Encrypt a Password using SHA-1
#
#      OPTIONS:  ---
# REQUIREMENTS:  ---
#         BUGS:  ---
#        NOTES:  ---
#       AUTHOR:  Gavin Henry (GH), <ghenry@suretecsystems.com>
#      COMPANY:  Suretec Systems Ltd.
#      VERSION:  1.0
#      CREATED:  26/06/2006
#     REVISION:  ---
#    COPYRIGHT:  http://search.cpan.org/dist/perl/pod/perlgpl.pod
#===============================================================================

use strict;
use warnings;
use Digest::SHA1;
use Term::ReadKey;

sub get_pass {
    ReadMode 'noecho';
    chomp( my $pw = ReadLine 0 );
    ReadMode 'normal';
    return $pw;
}

print "Enter the password to be encrypted: ";
my $pass = get_pass();

print "\nConfirm the password: ";
my $verify = get_pass();

if ( $pass eq $verify ) {
    my $sha1_enc = Digest::SHA1->new;
    $sha1_enc->add($pass);

    print "\nYour encrypted password is: "
      . $sha1_enc->hexdigest . "\n"
      . "Paste this into your SQL INSERT/COPY Data.\n";
}
else {
    print "\nPasswords do not match!\n";
}

AUTHOR

Kennedy Clark, hkclark@gmail.com

Please report any errors, issues or suggestions to the author. The most recent version of the Catalyst Tutorial can be found at http://dev.catalyst.perl.org/repos/Catalyst/Catalyst-Manual/5.70/trunk/lib/Catalyst/Manual/Tutorial/.

Copyright 2006-2008, Kennedy Clark, under Creative Commons License (http://creativecommons.org/licenses/by-sa/3.0/us/).