Intro to Dancer YAPC::NA 2012

A short introduction to the Dancer micro web framework in Perl.

Transcript

1. Introduction to Dancer! A Sinatra-inspired web framework for Perl! ! ! Mark Allen! mrallen1@yahoo.com! http://byte-me.org! https://github.com/mrallen1! https://bitbucket.org/mrallen1! https://metacpan.org/author/MALLEN!
2. The Old Days!
3. The Old Days cgi-lib.pl (1994-1998)! !
4. The Old Days CGI.pm (1995-2011)! !
5. The Old Days mod_perl (1996-2011)! !
6. The Old Days Matt’s Script Archive (1995-2011)! ! Use instead:! http://nms-cgi.sourceforge.net/! (Thanks London.pm)! !
7. The Old Days use CGI.pm;! ! my $q = CGI->new();! my ($a, $b, $c) = $q->param();! ! if ($a !~ /\d+/) {! !print $q->header(-status => ‘400 Bad request’);! !print “<h1>Value of ‘a’ ($a) is not an integer</h1>”;! !exit 0;! }! # yada, yada!
8. The Old Days .htaccess Hack! ! ! RewriteEngine On! RewriteBase /abc! ! RewriteRule ^(.*)/(.*)/(.*)$ !abc.pl?a=$1;b=$2;c=$3! !
9. The Old Days .htaccess Hack! ! # Use Web 2.0 style URLs, but keep CGI interface! RewriteEngine On! RewriteBase /abc! ! RewriteRule ^(.*)/(.*)/(.*)$ !abc.pl?a=$1;b=$2;c=$3! !
10. The Old Days .htaccess Hack! ! # Use Web 2.0 style URLs, but keep CGI interface! RewriteEngine On! RewriteBase /abc! ! RewriteRule ^(.*)/(.*)/(.*)$ !abc.pl?a=$1;b=$2;c=$3! !
11. The Old Days .htaccess Hack! ! # Use Web 2.0 style URLs, but keep CGI interface! RewriteEngine On! RewriteBase /abc! ! RewriteRule ^(.*)/(.*)/(.*)$ !abc.pl?a=$1;b=$2;c=$3! !
12. The Old Days h"p://flic.kr/p/5TWTR4  
13. The Old Days h"p://flic.kr/p/5TWTR4  
14. Move over bacon, now there’s something leaner.! !
15. Move over bacon Perl 5 Renaissance:! •  Moose! •  DBIx::Class! •  Plack! •  Tons of great new stuff in core perl 5.10+! !
16. Move over bacon Do you find Catalyst too ! heavyweight or intimidating?! !
17. Move over bacon ! Me too!! ! !
18. Move over bacon Enter Dancer! !
19. Move over bacon Other Sinatra-inspired frameworks:! •  Mojo (Perl – TMTOWTDI)! •  Flask (Python)! •  Fitzgerald (PHP)! •  Express (Node.js)! !
20. Move over bacon Dancer is:! •  Easy to learn! •  Expressive! •  Efficient!
21. Dancer is ...! ! Easy to learn!
22. Easy to learn Basic Dancer concepts:! •  One (or more) HTTP verb(s)! •  A route! •  A handler!
23. Easy to learn use Dancer;! ! get '/' => sub {! return 'Hello World!\n’;! };! ! start;!
24. Easy to learn use Dancer;! ! get '/' => sub {! return 'Hello World!\n’;! };! ! start;!
25. Easy to learn use Dancer;! ! get '/' => sub {! return 'Hello World!\n’;! };! ! start;!
26. Easy to learn use Dancer;! ! get '/' => sub {! return 'Hello World!\n’;! };! ! start;!
27. Easy to learn use Dancer;! ! get '/' => sub {! return 'Hello World!\n’;! };! ! start;!
28. Easy to learn
29. Easy to learn get '/' => sub {! my $db = connect_db();! my $sql = 'select id, title, text from entries order by id desc’;! my $sth = $db->prepare($sql) or die $db->errstr;! $sth->execute or die $sth->errstr;! template 'show_entries.tt', {! 'msg' => get_flash(),! 'add_entry_url' => uri_for('/add'),! 'entries' => $sth->fetchall_hashref('id'),! };! };!
30. Easy to learn get '/' => sub {! my $db = connect_db();! my $sql = 'select id, title, text from entries order by id desc’;! my $sth = $db->prepare($sql) or die $db->errstr;! $sth->execute or die $sth->errstr;! template 'show_entries.tt', {! 'msg' => get_flash(),! 'add_entry_url' => uri_for('/add'),! 'entries' => $sth->fetchall_hashref('id'),! };! };!
31. Easy to learn get '/' => sub {! my $db = connect_db();! my $sql = 'select id, title, text from entries order by id desc’;! my $sth = $db->prepare($sql) or die $db->errstr;! $sth->execute or die $sth->errstr;! template 'show_entries.tt', {! 'msg' => get_flash(),! 'add_entry_url' => uri_for('/add'),! 'entries' => $sth->fetchall_hashref('id'),! };! };!
32. Easy to learn get '/' => sub {! my $db = connect_db();! my $sql = 'select id, title, text from entries order by id desc’;! my $sth = $db->prepare($sql) or die $db->errstr;! $sth->execute or die $sth->errstr;! template 'show_entries.tt', {! 'msg' => get_flash(),! 'add_entry_url' => uri_for('/add'),! 'entries' => $sth->fetchall_hashref('id'),! };! };!
33. Easy to learn get '/' => sub {! my $db = connect_db();! my $sql = 'select id, title, text from entries order by id desc’;! my $sth = $db->prepare($sql) or die $db->errstr;! $sth->execute or die $sth->errstr;! template 'show_entries.tt', {! 'msg' => get_flash(),! 'add_entry_url' => uri_for('/add'),! 'entries' => $sth->fetchall_hashref('id'),! };! };!
34. Easy to learn get '/' => sub {! my $db = connect_db();! my $sql = 'select id, title, text from entries order by id desc’;! my $sth = $db->prepare($sql) or die $db->errstr;! $sth->execute or die $sth->errstr;! template 'show_entries.tt', {! 'msg' => get_flash(),! 'add_entry_url' => uri_for('/add'),! 'entries' => $sth->fetchall_hashref('id'),! };! };!
35. Easy to learn get '/' => sub {! my $db = connect_db();! my $sql = 'select id, title, text from entries order by id desc’;! my $sth = $db->prepare($sql) or die $db->errstr;! $sth->execute or die $sth->errstr;! template 'show_entries.tt', {! 'msg' => get_flash(),! 'add_entry_url' => uri_for('/add'),! 'entries' => $sth->fetchall_hashref('id'),! };! };!
36. Easy to learn get '/' => sub {! my $db = connect_db();! my $sql = 'select id, title, text from entries order by id desc’;! my $sth = $db->prepare($sql) or die $db->errstr;! $sth->execute or die $sth->errstr;! template 'show_entries.tt', {! 'msg' => get_flash(),! 'add_entry_url' => uri_for('/add'),! 'entries' => $sth->fetchall_hashref('id'),! };! };!
37. Easy to learn get '/' => sub {! my $db = connect_db();! my $sql = 'select id, title, text from entries order by id desc’;! my $sth = $db->prepare($sql) or die $db->errstr;! $sth->execute or die $sth->errstr;! template 'show_entries.tt', {! 'msg' => get_flash(),! 'add_entry_url' => uri_for('/add'),! 'entries' => $sth->fetchall_hashref('id'),! };! };!
38. Easy to learn show_entries.tt! ! <ul class=entries>! <% IF entries.size %>! <% FOREACH id IN entries.keys.nsort %>! <li><h2><% entries.$id.title %></h2>! <% entries.$id.text %>! <% END %>! <% ELSE %>! <li><em>Unbelievable. No entries here so far</em>! <% END %>! </ul>! 
 !
39. Easy to learn show_entries.tt! ! <ul class=entries>! <% IF entries.size %>! <% FOREACH id IN entries.keys.nsort %>! <li><h2><% entries.$id.title %></h2>! <% entries.$id.text %>! <% END %>! <% ELSE %>! <li><em>Unbelievable. No entries here so far</em>! <% END %>! </ul>! 
 !
40. Easy to learn show_entries.tt! ! <ul class=entries>! <% IF entries.size %>! <% FOREACH id IN entries.keys.nsort %>! <li><h2><% entries.$id.title %></h2>! <% entries.$id.text %>! <% END %>! <% ELSE %>! <li><em>Unbelievable. No entries here so far</em>! <% END %>! </ul>! 
 !
41. Easy to learn show_entries.tt! ! <ul class=entries>! <% IF entries.size %>! <% FOREACH id IN entries.keys.nsort %>! <li><h2><% entries.$id.title %></h2>! <% entries.$id.text %>! <% END %>! <% ELSE %>! <li><em>Unbelievable. No entries here so far</em>! <% END %>! </ul>! 
 !
42. Easy to learn get '/' => sub {! my $db = connect_db();! my $sql = 'select id, title, text from entries order by id desc’;! my $sth = $db->prepare($sql) or die $db->errstr;! $sth->execute or die $sth->errstr;! template 'show_entries.tt', {! 'msg' => get_flash(),! 'add_entry_url' => uri_for('/add'),! 'entries' => $sth->fetchall_hashref('id'),! };! };!
43. Easy to learn show_entries.tt! ! <ul class=entries>! <% IF entries.size %>! <% FOREACH id IN entries.keys.nsort %>! <li><h2><% entries.$id.title %></h2>! <% entries.$id.text %>! <% END %>! <% ELSE %>! <li><em>Unbelievable. No entries here so far</em>! <% END %>! </ul>! 
 !
44. Easy to learn show_entries.tt! ! <ul class=entries> <!– CSS class -->! <% IF entries.size %>! <% FOREACH id IN entries.keys.nsort %>! <li><h2><% entries.$id.title %></h2>! <% entries.$id.text %>! <% END %>! <% ELSE %>! <li><em>Unbelievable. No entries here so far</em>! <% END %>! </ul>! 
 !
45. Easy to learn Directory structure
 ! dancr/! ├── dancr.pl! ├── public! │ └── css! │ └── style.css! └── views! ├── layouts! │ └── main.tt! ├── login.tt! └── show_entries.tt!
46. Easy to learn Directory structure
 ! dancr/! ├── dancr.pl! ├── public! │ └── css! │ └── style.css! └── views! ├── layouts! │ └── main.tt! ├── login.tt! └── show_entries.tt!
47. Easy to learn Directory structure
 ! dancr/! ├── dancr.pl! ├── public! │ └── css! │ └── style.css! └── views! ├── layouts! │ └── main.tt! ├── login.tt! └── show_entries.tt!
48. Easy to learn Directory structure
 ! dancr/! ├── dancr.pl! ├── public! │ └── css! │ └── style.css! └── views! ├── layouts! │ └── main.tt! ├── login.tt! └── show_entries.tt!
49. Dancer is...! ! Expressive!
50. Expressive post '/add' => sub {! if ( not session('logged_in') ) {! return send_error("Not logged in", 401);! }! ! my $db = connect_db();! my $sql = 'insert into entries (title, text) values (?, ?)’;! my $sth = $db->prepare($sql)
 or die $db->errstr;! $sth->execute(params->{'title'}, 
 params->{'text'}) 
 or die $sth->errstr;! ! set_flash('New entry posted!');! redirect '/’;! };!
51. Expressive post '/add' => sub {! if ( not session('logged_in') ) {! return send_error("Not logged in", 401);! }! ! my $db = connect_db();! my $sql = 'insert into entries (title, text) values (?, ?)’;! my $sth = $db->prepare($sql)
 or die $db->errstr;! $sth->execute(params->{'title'}, 
 params->{'text'}) 
 or die $sth->errstr;! ! set_flash('New entry posted!');! redirect '/’;! };!
52. Expressive post '/add' => sub {! if ( not session('logged_in') ) {! return send_error("Not logged in", 401);! }! ! my $db = connect_db();! my $sql = 'insert into entries (title, text) values (?, ?)’;! my $sth = $db->prepare($sql)
 or die $db->errstr;! $sth->execute(params->{'title'}, 
 params->{'text'}) 
 or die $sth->errstr;! ! set_flash('New entry posted!');! redirect '/’;! };!
53. Expressive post '/add' => sub {! if ( not session('logged_in') ) {! return send_error("Not logged in", 401);! }! ! my $db = connect_db();! my $sql = 'insert into entries (title, text) values (?, ?)’;! my $sth = $db->prepare($sql)
 or die $db->errstr;! $sth->execute(params->{'title'}, 
 params->{'text'}) 
 or die $sth->errstr;! ! set_flash('New entry posted!');! redirect '/’;! };!
54. Expressive post '/add' => sub {! if ( not session('logged_in') ) {! return send_error("Not logged in", 401);! }! ! my $db = connect_db();! my $sql = 'insert into entries (title, text) values (?, ?)’;! my $sth = $db->prepare($sql)
 or die $db->errstr;! $sth->execute(params->{'title'}, 
 params->{'text'}) 
 or die $sth->errstr;! ! set_flash('New entry posted!');! redirect '/’;! };!
55. Expressive post '/add' => sub {! if ( not session('logged_in') ) {! return send_error("Not logged in", 401);! }! ! my $db = connect_db();! my $sql = 'insert into entries (title, text) values (?, ?)’;! my $sth = $db->prepare($sql)
 or die $db->errstr;! $sth->execute(params->{'title'}, 
 params->{'text'}) 
 or die $sth->errstr;! ! set_flash('New entry posted!');! redirect '/’;! };!
56. Expressive post '/add' => sub {! if ( not session('logged_in') ) {! return send_error("Not logged in", 401);! }! ! my $db = connect_db();! my $sql = 'insert into entries (title, text) values (?, ?)’;! my $sth = $db->prepare($sql)
 or die $db->errstr;! $sth->execute(params->{'title'}, 
 params->{'text'}) 
 or die $sth->errstr;! ! set_flash('New entry posted!');! redirect '/’;! };!
57. Expressive Little Bobby Tables! h"p://xkcd.com/327/  
58. Expressive post '/add' => sub {! if ( not session('logged_in') ) {! return send_error("Not logged in", 401);! }! # http://bobby-tables.com! my $db = connect_db();! my $sql = 'insert into entries (title, text) values (?, ?)’;! my $sth = $db->prepare($sql)
 or die $db->errstr;! $sth->execute(params->{'title'}, 
 params->{'text'}) 
 or die $sth->errstr;! ! set_flash('New entry posted!');! redirect '/’;! };!
59. Expressive
60. Expressive Configuration
 ! •  Session Engine! •  Template Engine! •  Logging ! •  Plugins!
61. Expressive Configuration Examples! 
 
 set 'session' => 'Simple';
 set 'template' =>'template_toolkit';
 set 'logger' => 'console';
 set 'log' => 'debug';
 set 'show_errors' => 1;
 !
62. Expressive Configuration Examples! 
 
 set 'session' => 'Simple';
 set 'template' =>'template_toolkit';
 set 'logger' => 'console';
 set 'log' => 'debug';
 set 'show_errors' => 1;
 !
63. Expressive Configuration
 
 Use any non-reserved key/value pair.
 
 set 'username' => 'admin';
 set 'password' => 'password';! !
64. Expressive Routes with regex! ! 
 get qr{\A\/(?<code>[A-Za-z0-9]+)\Z} => sub {! my $decode = decode_base36(
 uc captures->{'code'}! );! ...;! };!
65. Expressive Routes with regex! ! 
 get qr{\A\/(?<code>[A-Za-z0-9]+)\Z} => sub {! my $decode = decode_base36(
 uc captures->{'code'}! );! ...;! };!
66. Expressive Routes with regex! ! use v5.10;
 get qr{\A\/(?<code>[A-Za-z0-9]+)\Z} => sub {! my $decode = decode_base36(
 uc captures->{'code'}! );! ...;! };!
67. Expressive Routes with regex! ! use v5.10;
 get qr{\A\/(?<code>[A-Za-z0-9]+)\Z} => sub {! my $decode = decode_base36(
 uc captures->{'code'}! );! ...;! };!
68. Expressive Routes with named params! ! get '/:code/stats' => sub {! my $decode = decode_base36(
 uc params->{'code'}
 );! ...;! };!
69. Expressive Routes with named params! ! get '/:code/stats' => sub {! my $decode = decode_base36(
 uc params->{'code'}
 );! ...;! };!
70. Expressive Routes with named params! ! get qr{^/(.+)/stats$} => sub {
 params(‘code’) = $1;
 # input sanity goes here
 ...;
 };!
71. Expressive use CGI.pm;! ! my $q = CGI->new();! my ($a, $b, $c) = $q->param();! ! if ($a !~ /\d+/) {! !print $q->header(-status => ‘400 Bad request’);! !print “<h1>Value of ‘a’ ($a) is not an integer</h1>”;! !exit 0;! }! # yada, yada!
72. Expressive ! ! ! ! use v5.10;
 use Dancer;
 
 ! get qr{/(?<a>\d+)/(?<b>.+)/(?<c>.+)} => sub {! # Route will only match if a is an integer!
 # No more sanitation/validation necessary
 ...;
 };! !
73. Dancer is...
 
 ! Efficient!
74. Efficient any ['get', 'post'] => '/login' => sub {! my $err;! if ( request->is_post ) {! if ( params->{'username'} ne setting('username') ) {! $err = "Invalid username”;! }! elsif ( params->{'password'} ne setting('password') ) {! $err = "Invalid password”;! }! else {! session 'logged_in' => true;! set_flash('You are logged in.');! redirect '/’;! }! }! template 'login.tt', {! 'err' => $err,! };! };!
75. Efficient any ['get', 'post'] => '/login' => sub {! my $err;! if ( request->is_post ) {! if ( params->{'username'} ne setting('username') ) {! $err = "Invalid username”;! }! elsif ( params->{'password'} ne setting('password') ) {! $err = "Invalid password”;! }! else {! session 'logged_in' => true;! set_flash('You are logged in.');! redirect '/’;! }! }! template 'login.tt', {! 'err' => $err,! };! };!
76. Efficient any ['get', 'post'] => '/login' => sub {! my $err;! if ( request->is_post ) {! if ( params->{'username'} ne setting('username') ) {! $err = "Invalid username”;! }! elsif ( params->{'password'} ne setting('password') ) {! $err = "Invalid password”;! }! else {! session 'logged_in' => true;! set_flash('You are logged in.');! redirect '/’;! }! }! template 'login.tt', {! 'err' => $err,! };! };!
77. Efficient any ['get', 'post'] => '/login' => sub {! my $err;! if ( request->is_post ) {! if ( params->{'username'} ne setting('username') ) {! $err = "Invalid username”;! }! elsif ( params->{'password'} ne setting('password') ) {! $err = "Invalid password”;! }! else {! session 'logged_in' => true;! set_flash('You are logged in.');! redirect '/’;! }! }! template 'login.tt', {! 'err' => $err,! };! };!
78. Efficient any ['get', 'post'] => '/login' => sub {! my $err;! if ( request->is_post ) {! if ( params->{'username'} ne setting('username') ) {! $err = "Invalid username”;! }! elsif ( params->{'password'} ne setting('password') ) {! $err = "Invalid password”;! }! else {! session 'logged_in' => true;! set_flash('You are logged in.');! redirect '/’;! }! }! template 'login.tt', {! 'err' => $err,! };! };!
79. Efficient any ['get', 'post'] => '/login' => sub {! my $err;! if ( request->is_post ) {! if ( params->{'username'} ne setting('username') ) {! $err = "Invalid username”;! }! elsif ( params->{'password'} ne setting('password') ) {! $err = "Invalid password”;! }! else {! session 'logged_in' => true;! set_flash('You are logged in.');! redirect '/’;! }! }! template 'login.tt', {! 'err' => $err,! };! };!
80. Efficient any ['get', 'post'] => '/login' => sub {! my $err;! if ( request->is_post ) {! if ( params->{'username'} ne setting('username') ) {! $err = "Invalid username”;! }! elsif ( params->{'password'} ne setting('password') ) {! $err = "Invalid password”;! }! else {! session 'logged_in' => true;! set_flash('You are logged in.');! redirect '/’;! }! }! template 'login.tt', {! 'err' => $err,! };! };!
81. Efficient any ['get', 'post'] => '/login' => sub {! my $err;! if ( request->is_post ) {! if ( params->{'username'} ne setting('username') ) {! $err = "Invalid username”;! }! elsif ( params->{'password'} ne setting('password') ) {! $err = "Invalid password”;! }! else {! session 'logged_in' => true;! set_flash('You are logged in.');! redirect '/’;! }! }! template 'login.tt', {! 'err' => $err,! };! };!
82. Efficient Hook Before / After! •  De/Serialization! •  Rendering! •  Template! •  Errors!
83. Efficient Forward! ! get '/demo/foo/:bar' => sub {! my $bar = param->{'bar'};! # magically use demo DB! ...;! return forward "/foo/$bar";! };! !
84. Efficient Prefix! ! prefix '/user'; # begins scope! ! get '/view/:id' => sub { ...; };! post '/add' => sub { ...; };! any ['get', 'post'] => '/edit/:id' => sub { ...; };! ! prefix undef; # ends scope! ! get '/view/:id' => sub { ...; };!
85. Efficient Dancer Plugins add keywords
 ! •  Auto-create RSS feeds! •  Integrate Twitter for authN! •  DBIx::Class! •  DWIM CRUD apps! •  ...and more!
86. Efficient Dancer::Plugin::Database
 ! database keyword gets $dbh! ! my $sth = database->prepare("SELECT * FROM mytable WHERE id = ?");! $sth->execute(42);! template 'userdetail.tt', {! row => $sth->fetchrow_hashref()! };!
87. Efficient Sweet, sweet syntactic sugar:! ! ! database->quick_insert('mytable', \%data);! template 'userdetail.tt', {! row => database->quick_select('mytable', { id => 42 })! };! !
88. Dancer is...! ! Awesome! !
89. Awesome Source code:! { hg | git } clone https://bitbucket.org/mrallen1/dancr! ! See also:! https://metacpan.org/module/Dancer! https://metacpan.org/module/Dancer::Plugin::Database
 ! Install:! curl -L http://cpanmin.us | perl - Dancer YAML Template! !
90. Awesome Thank You!! !