# NAME

# NAME

Kossy - Sinatra-ish Simple and Clear web application framework

# SYNOPSIS

% kossy-setup MyApp
% cd MyApp
% plackup app.psgi

## lib/MyApp/Web.pm

use Kossy;

get '/' => sub {
my ( $self, $c ) = @_;
$c->render('index.tx', { greeting => "Hello!" });
};

get '/json' => sub {
my ( $self, $c ) = @_;
my $result = $c->req->validator([
'q' => {
default => 'Hello',
rule => [
[['CHOICE',qw/Hello Bye/],'Hello or Bye']
],
}
]);
$c->render_json({ greeting => $result->valid->get('q') });
};

1;

## views/index.tx
: cascade base
: around content -> {
<: $greeting :>
: }

# DESCRIPTION

Kossy is Sinatra-ish Simple and Clear web application framework, which is based upon [Plack](https://metacpan.org/pod/Plack), [Router::Boom](https://metacpan.org/pod/Router::Boom), [Text::Xslate](https://metacpan.org/pod/Text::Xslate) and build-in Form-Validator. That's suitable for small application and rapid development.

# Kossy class

Kossy exports some methods to building application

## CLASS METHODS for Kossy class

- my $kossy = Kossy->new( root\_dir => $root\_dir );

Create instance of the application object.

## OBJECT METHODS for Kossy class

- my $root\_dir = $kossy->root\_dir();

accessor to root directory of the application

- my $app = $kossy->psgi();

return PSGI application

## DISPATCHER METHODS for Kossy class

- filter

makes application wrapper like plack::middlewares.

filter 'set_title' => sub {
my $app:CODE = shift;
sub {
my ( $self:Kossy, $c:Kossy::Connection ) = @_;
$c->stash->{site_name} = __PACKAGE__;
$app->($self,$c);
}
};

- get path:String => \[\[filters\] =>\] CODE
- post path:String => \[\[filters\] =>\] CODE

setup router and dispatch code

get '/' => [qw/set_title/] => sub {
my ( $self:Kossy, $c:Kossy::Connection ) = @_;
$c->render('index.tx', { greeting => "Hello!" });
};

get '/json' => sub {
my ( $self:Kossy, $c:Kossy::Connection ) = @_;
$c->render_json({ greeting => "Hello!" });
};

dispatch code shall return Kossy::Response object or PSGI response ArrayRef or String.

- router 'HTTP\_METHOD'|\['METHOD'\[,'METHOD'\]\] => path:String => \[\[filters\] =>\] CODE

adds routing rule other than GET and POST

router 'PUT' => '/put' => sub {
my ( $self:Kossy, $c:Kossy::Connection ) = @_;
$c->render_json({ greeting => "Hello!" });
};

# Kossy::Connection class

per-request object, herds request and response

## OBJECT METHODS for Kossy::Connection class

- req:Kossy::Request
- res:Kossy::Response
- stash:HashRef
- args:HashRef

Router::Simple->match result

- halt(status\_code, message)

die and response immediately

- redirect($uri,status\_code): Kossy::Response
- render($file,$args): Kossy::Response

calls Text::Xslate->render makes response. template files are searching in root\_dir/views directory

template syntax is Text::Xslate::Syntax::Kolon, can use Kossy::Connection object and fillinform block.

## template.tx
: block form | fillinform( $c.req ) -> {
<head>
<title><: $c.stash.title :></title>
</head>
<body>
<form action="<: $c.req.uri_for('/post') :>">
<input type="text" size="10" name="title" />
<textarea name="body" rows="20" cols="90"></textarea>
</form>
</body>
: }

also can use [Text::Xslate::Bridge::TT2Like](https://metacpan.org/pod/Text::Xslate::Bridge::TT2Like) and [Number::Format](https://metacpan.org/pod/Number::Format) methods in your template

- render\_json($args): Kossy::Response

serializes arguments with JSON and makes response

This method escapes '<', '>', and '+' characters by "\\uXXXX" form. Browser don't detects the JSON as HTML. And also this module outputs "X-Content-Type-Options: nosniff" header for IEs.

render\_json have a JSON hijacking detection feature same as [Amon2::Plugin::Web::JSON](https://metacpan.org/pod/Amon2::Plugin::Web::JSON). This returns "403 Forbidden" response if following pattern request.

- The request have 'Cookie' header.
- The request doesn't have 'X-Requested-With' header.
- The request contains /android/i string in 'User-Agent' header.
- Request method is 'GET'

# Kossy::Request

This class is child class of Plack::Request, decode query/body parameters automatically. Return value of $req->param(), $req->body\_parameters, etc. is the decoded value.

## OBJECT METHODS for Kossy::Request class

- uri\_for($path,$args):String

build absolute URI with path and $args

my $uri = $c->req->uri_for('/login',[ arg => 'Hello']);

- validator($rule):Kossy::Validator::Result

validate parameters using [Kossy::Validator](https://metacpan.org/pod/Kossy::Validator)

my $result = $c->req->validator([
'q' => [['NOT_NULL','query must be defined']],
'level' => {
default => 'M',
rule => [
[['CHOICE',qw/L M Q H/],'invalid level char'],
],
},
]);

my $val = $result->valid('q');
my $val = $result->valid('level');

- body\_parameters\_raw
- query\_parameters\_raw
- parameters\_raw
- param\_raw

These methods are the accessor to raw values. 'raw' means the value is not decoded.

# Kossy::Response

This class is child class of Plack::Response

# CUSTOMIZE

- X-Frame-Options

By default, Kossy outputs "X-Frame-Options: DENY". You can change this header

get '/iframe' => sub {
my ($self, $c) = @_;
$c->res->header('X-Frame-Options','SAMEORIGIN');
# or remove from response header
# delete $c->res->headers->remove_header('X-Frame-Options');
..
}

(Default: DENY)

- kossy.request.parse\_json\_body

If enabled, Kossy will decode json in the request body that has "application/json" content header

post '/api' => sub {
my ($self, $c) = @_;
$c->env->{'kossy.request.parse_json_body'} = 1;
my val = $c->req->param('foo'); # bar
}

# requrest
# $ua->requrest(
# HTTP::Request->new(
# "POST",
# "http://example.com/api",
# [ "Content-Type" => 'application/json', "Content-Length" => 13 ],
# '{"foo":"bar"}'
# )
# );

- $XSLATE\_CACHE, $XSLATE\_CACHE\_DIR

Change xslate's cache level and cache directory.

local $Kossy::XSLATE_CACHE = 2;
local $Kossy::XSLATE_CACHE_DIR = $dir;
my $app = MyApp::Web->psgi;

By default, $XSLATE\_CACHE is 1, $XSLATE\_CACHE\_DIR is undef. use Xslate's default.

- $SECURITY\_HEADER

If disabled, Kossy does not set X-Frame-Options and X-XSS-Protection. enabled by default.

local $Kossy::SECURITY_HEADER = 0;
my $app = MyApp::Web->psgi;

Can not change $Kossy::SECURITY\_HEADER in your WebApp. It's need to set at build time.

This is useful for the benchmark :-)

# AUTHOR

Masahiro Nagano <kazeburo {at} gmail.com>

# SEE ALSO

Kossy is small waf, that has only 400 lines code. so easy to reading framework code and customize it. Sinatra-ish router, build-in templating, validators and zero-configuration features are suitable for small application and rapid development.

[Amon2::Lite](https://metacpan.org/pod/Amon2::Lite)

[Mojolicious::Lite](https://metacpan.org/pod/Mojolicious::Lite)

[Dancer](https://metacpan.org/pod/Dancer)

[Kossy::Validator](https://metacpan.org/pod/Kossy::Validator)

# LICENSE of HTTP::Headers::Fast

Kossy::Headers uses [HTTP::Headers::Fast](https://metacpan.org/pod/HTTP::Headers::Fast) code. Here is LICENSE of HTTP::Headers::Fast

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.

# LICENSE

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.