Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.
Dancer
(the Effortless Perl Web Framework)
About me
●   Sawyer X
●   Sysadmin / Perl Ninja
●   Israel.pm / Haifa.pm / TelAviv.pm / Rehovot.pm
●   I do system, networ...
Perl web recap




    1995
    CGI
Perl web recap



               2010
    Many frameworks
(including micro-frameworks like Dancer)
The big web religions, illustrated
Ruby – the fanboys
Python – the sticklers
PHP – the nonsensical
Perl – the nutcases
Nutcases?
●   Yes, we are insane (but not LISP-insane)
●   Insanity is a whole lot of fun!
●   Insanity gives us flexibili...
Flask (Pythonese)
from flask import Flask
app = Flask(__name__)


@app.route("/", methods=['GET'])
def hello():
    return...
Dancer (Perlesque)
use Dancer;


get “/hi” => sub {
    “Hello, World!”
};


dance;
In comparison
from flask import Flask            use Dancer;
app = Flask(__name__)


@app.route("/", methods=['GET'])   ge...
Dancer treats
●   Both read and write, easily!
●   Route-based (started as a port of Sinatra)
●   PSGI/Plack compliant (PS...
Recipe for Dancing
●   Take an HTTP method
●   Add a path to that
●   Mix with a subroutine
●   And sprinkle plugins and k...
Dancer route structure
get     '/path' => sub { … };
post    '/path' => sub { … };
put     '/path' => sub { … };
del     '...
Dancer
●   Paths can contain variables
    get '/hello/:entity/'


●   Paths can be Regular Expressions
    get qr{/ (w+) ...
Dancer login example
post '/login' => sub {
    # Validate the username and password
    if ( params­>{user} eq 'bob' &&
 ...
Templating
get '/' => sub {
    template index => {
        greeting => 'welcome'
    }
};
More nifty stuff
●   headers 'My­X­Header' => 'Value'
●   send_file('report.tar.gz')
●   set_cookie name    => 'value',
  ...
Dancer as Perl philosophy
●   Dancer is succinct, efficient and easy to work with
●   Dancer is daring
    (Do you have ro...
Oh yeah, route caching...
Dancer::Plugin::REST
get '/user/:id.:format' => sub {
    UserRS­>find( params­>{id} );
};
# curl http://mywebservice/user...
Dancer::Plugin::SiteMap
    use Dancer::Plugin::SiteMap;


●   You get: /sitemap and /sitemap.xml
●   “Yup, it's that simp...
Dancer::Plugin::Email
post '/contact' => sub {
    email {
        to      => 'a@b.com',
        subject => 'Test',
      ...
Dancer::Plugin::Authorize
post '/login' => sub {
    my $user = params­>{'user'};
    my $pass = params­>{'pass'};
    if ...
Dancer::Plugin::Ajax
    ajax '/check_for_update' => sub {
        # some ajax code
    };

●   Pass if X-Request-With not...
Dancer::Plugin::DBIC
●   DBIC (DBIx::Class) – a sophisticated ORM
●   Configure the connection in the config file
●   Make...
Dancer::Plugin::Database
●   Database(s) connection in Dancer
    get '/widget/view/:id' => sub {
       my $sth = databas...
In culmination
  Dancer is beautiful and fun
The way programming should be



        PerlDancer.org
search.cpan.org/perld...
Perl Dancer for Python programmers
Upcoming SlideShare
Loading in …5
×

Perl Dancer for Python programmers

28,056 views

Published on

This is a talk given at PyWeb IL Oct 4th.

Published in: Technology

Perl Dancer for Python programmers

  1. 1. Dancer (the Effortless Perl Web Framework)
  2. 2. About me ● Sawyer X ● Sysadmin / Perl Ninja ● Israel.pm / Haifa.pm / TelAviv.pm / Rehovot.pm ● I do system, networking, web, applications, etc. ● http://blogs.perl.org/users/sawyer_x/ ● http://search.cpan.org/~xsawyerx/
  3. 3. Perl web recap 1995 CGI
  4. 4. Perl web recap 2010 Many frameworks (including micro-frameworks like Dancer)
  5. 5. The big web religions, illustrated
  6. 6. Ruby – the fanboys
  7. 7. Python – the sticklers
  8. 8. PHP – the nonsensical
  9. 9. Perl – the nutcases
  10. 10. Nutcases? ● Yes, we are insane (but not LISP-insane) ● Insanity is a whole lot of fun! ● Insanity gives us flexibility ● Flexibility gives us cool stuff ● Like Moose and meta-programming ● Like DBIx::Class ● Like Dancer
  11. 11. Flask (Pythonese) from flask import Flask app = Flask(__name__) @app.route("/", methods=['GET']) def hello():     return "Hello World!" if __name__ == "__main__":     app.run()
  12. 12. Dancer (Perlesque) use Dancer; get “/hi” => sub {     “Hello, World!” }; dance;
  13. 13. In comparison from flask import Flask use Dancer; app = Flask(__name__) @app.route("/", methods=['GET']) get “/” => sub { def hello():   “Hello, World!”     return "Hello World!" }; if __name__ == "__main__":     app.run() dance;
  14. 14. Dancer treats ● Both read and write, easily! ● Route-based (started as a port of Sinatra) ● PSGI/Plack compliant (PSGI is our WSGI) ● Minimum dependencies ● Any app is also a web server ● CPAN-friendly (<3 CPAN)
  15. 15. Recipe for Dancing ● Take an HTTP method ● Add a path to that ● Mix with a subroutine ● And sprinkle plugins and keywords on top
  16. 16. Dancer route structure get     '/path' => sub { … }; post    '/path' => sub { … }; put     '/path' => sub { … }; del     '/path' => sub { … }; options '/path' => sub { … }; any     '/path' => sub { … };
  17. 17. Dancer ● Paths can contain variables get '/hello/:entity/' ● Paths can be Regular Expressions get qr{/ (w+) / d{2,3} (.+)? }x
  18. 18. Dancer login example post '/login' => sub {     # Validate the username and password     if ( params­>{user} eq 'bob' &&          params­>{pass} eq 'LetMeIn' ) {         session user => params­>{user};         redirect params­>{path} || '/';     } else {         redirect '/login?failed=1';     }  };
  19. 19. Templating get '/' => sub {     template index => {         greeting => 'welcome'     } };
  20. 20. More nifty stuff ● headers 'My­X­Header' => 'Value' ● send_file('report.tar.gz') ● set_cookie name    => 'value',            expires => ( time + 3600 ),            domain  => 'foo.com' ● status 'not_found' ● to_json, to_yaml, to_xml ● my $file        = upload('file_input') ● my $all_uploads = request­>uploads
  21. 21. Dancer as Perl philosophy ● Dancer is succinct, efficient and easy to work with ● Dancer is daring (Do you have route caching in Django?) (Websockets in near future!) ● Dancer has a lot of plugins: (engines for sessions, logging, templates) ● Serializers (JSON, YAML, XML) ● Route filters (before, after, before_template)
  22. 22. Oh yeah, route caching...
  23. 23. Dancer::Plugin::REST get '/user/:id.:format' => sub {     UserRS­>find( params­>{id} ); }; # curl http://mywebservice/user/42.json { "id": 42, "name": "John Foo",              "email": "john.foo@hopkins.com" } # curl http://mywebservice/user/42.yml ­­ id: 42 name: "John Foo" email: "john.foo@hopkins.com"
  24. 24. Dancer::Plugin::SiteMap use Dancer::Plugin::SiteMap; ● You get: /sitemap and /sitemap.xml ● “Yup, it's that simple.”
  25. 25. Dancer::Plugin::Email post '/contact' => sub {     email {         to      => 'a@b.com',         subject => 'Test',         message => $msg,         attach  => [ path => 'name' ],     } };
  26. 26. Dancer::Plugin::Authorize post '/login' => sub {     my $user = params­>{'user'};     my $pass = params­>{'pass'};     if ( auth( $user, $pass ) ) {         if ( auth_asa('guest')  ) {...}         if ( auth_can('create') ) {...}     } };
  27. 27. Dancer::Plugin::Ajax ajax '/check_for_update' => sub {     # some ajax code }; ● Pass if X-Request-With not “XMLHttpRequest” ● Disable the layout ● The action built is a POST request
  28. 28. Dancer::Plugin::DBIC ● DBIC (DBIx::Class) – a sophisticated ORM ● Configure the connection in the config file ● Make the ResultSets available in routes
  29. 29. Dancer::Plugin::Database ● Database(s) connection in Dancer get '/widget/view/:id' => sub {    my $sth = database­>prepare(         'select * from widgets where id = ?'    );    $sth­>execute( params­>{id} );    template display_widget => {        widget => $sth­>fetchrow_hashref,    }; };
  30. 30. In culmination Dancer is beautiful and fun The way programming should be PerlDancer.org search.cpan.org/perldoc?Dancer

×