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package Koha::Service; |
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# This file is part of Koha. |
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# |
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# Copyright (C) 2014 ByWater Solutions |
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# |
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# Koha is free software; you can redistribute it and/or modify it |
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# under the terms of the GNU General Public License as published by |
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# the Free Software Foundation; either version 3 of the License, or |
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# (at your option) any later version. |
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# |
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# Koha is distributed in the hope that it will be useful, but |
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# WITHOUT ANY WARRANTY; without even the implied warranty of |
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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# GNU General Public License for more details. |
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# |
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# You should have received a copy of the GNU General Public License |
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# along with Koha; if not, see <http://www.gnu.org/licenses>. |
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|
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=head1 NAME |
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Koha::Service - base class for webservices. |
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|
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=head1 SYNOPSIS |
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package Koha::Service::Frobnicator; |
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use base 'Koha::Service'; |
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sub new { |
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my ( $class ) = @_; |
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return $class::SUPER::new( { frobnicate => 1 } ); |
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} |
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sub run { |
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my ( $self ) = @_; |
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my ( $query, $cookie ) = $self->authenticate; |
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my ( $borrowernumber ) = $self->require_params( 'borrowernumber' ); |
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$self->croak( 'internal', 'Frobnication failed', { frobnicator => 'foo' } ); |
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$self->output({ frobnicated => 'You' }); |
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} |
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Koha::Service::Frobnicator->new->run; |
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=head1 DESCRIPTION |
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This module serves as a base class with utility methods for JSON webservices. |
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=head1 METHODS |
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|
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=cut |
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use Modern::Perl; |
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use base 'Class::Accessor'; |
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use C4::Auth qw( check_api_auth ); |
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use C4::Output qw( :ajax ); |
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use CGI; |
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use JSON; |
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our $debug; |
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BEGIN { |
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$debug = $ENV{DEBUG} || 0; |
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} |
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__PACKAGE__->mk_accessors( qw( auth_status query cookie ) ); |
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=head2 new |
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my $self = $class->SUPER::new( \%options ); |
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Base constructor for a service. |
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C<\%options> may contain the following: |
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=over |
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|
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=item authnotrequired |
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Defaults to false. If set, means that C<authenticate> will not croak if the user is not logged in. |
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=item needed_flags |
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Takes a hashref of required permissions, i.e., { circulation => |
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'circulate_remaining_permissions' }. |
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=item routes |
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An arrayref of routes; see C<add_routes> for the required format. |
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=back |
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=cut |
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sub new { |
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my ( $class, $options ) = @_; |
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return bless { |
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authnotrequired => 0, |
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needed_flags => { catalogue => 1 }, |
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routes => [], |
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%$options |
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}, $class; |
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} |
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=head2 authenticate |
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my ( $query, $cookie ) = $self->authenticate(); |
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Authenticates the user and returns a C<CGI> object and cookie. May exit after sending an 'auth' |
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error if the user is not logged in or does not have the right permissions. |
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This must be called before the C<croak> or C<output> methods. |
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=cut |
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sub authenticate { |
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my ( $self ) = @_; |
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$self->query(CGI->new); |
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my ( $status, $cookie, $sessionID ) = check_api_auth( $self->query, $self->{needed_flags} ); |
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$self->cookie($cookie); |
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$self->auth_status($status); |
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$self->croak( 'auth', $status ) if ( $status ne 'ok' && !$self->{authnotrequired} ); |
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return ( $self->query, $cookie ); |
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} |
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=head2 output |
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$self->output( $response[, \%options] ); |
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Outputs C<$response>, with the correct headers. |
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C<\%options> may contain the following: |
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=over |
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=item status |
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The HTTP status line to send; defaults to '200 OK'. This parameter is ignored for JSONP, as a |
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non-200 response cannot be easily intercepted. |
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=item type |
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Either 'js', 'json', 'xml' or 'html'. Defaults to 'json'. If 'json', and the C<callback> query parameter |
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is given, outputs JSONP. |
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=back |
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=cut |
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sub output { |
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my ( $self, $response, $options ) = @_; |
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binmode STDOUT, ':encoding(UTF-8)'; |
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# Set defaults |
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$options = { |
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status => '200 OK', |
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type => 'json', |
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%{ $options || {} }, |
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}; |
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if ( $options->{type} eq 'json' ) { |
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$response = encode_json($response); |
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if ( $self->query->param( 'callback' ) ) { |
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$response = $self->query->param( 'callback' ) . '(' . encode_json($response) . ');'; |
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$options->{status} = '200 OK'; |
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$options->{type} = 'js'; |
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} |
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} |
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output_with_http_headers $self->query, $self->cookie, $response, $options->{type}, $options->{status}; |
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} |
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=head2 croak |
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$self->croak( $error, $detail, \%flags ); |
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Outputs an error as JSON, then exits the service with HTTP status 400. |
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C<$error> should be a short, lower case code for the generic type of error (such |
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as 'auth' or 'input'). |
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C<$detail> should be a more specific code giving information on the error. If |
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multiple errors of the same type occurred, they should be joined by '|'; i.e., |
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'expired|different_ip'. Information in C<$error> does not need to be |
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human-readable, as its formatting should be handled by the client. |
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Any additional information to be given in the response should be passed in \%flags. |
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The final result of this is a JSON structure like so: |
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{ "error": "$error", "detail": "$detail", ... } |
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=cut |
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sub croak { |
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my ( $self, $type, $error, $flags ) = @_; |
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my $response = $flags || {}; |
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$response->{message} = $error; |
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$response->{error} = $type; |
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$self->output( $response, { status => '400 Bad Request' } ); |
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exit; |
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} |
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=head2 require_params |
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my @values = $self->require_params( @params ); |
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Check that each of of the parameters specified in @params was sent in the |
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request, then return their values in that order. |
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If a required parameter is not found, send a 'param' error to the browser. |
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=cut |
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sub require_params { |
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my ( $self, @params ) = @_; |
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my @values; |
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for my $param ( @params ) { |
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$self->croak( 'params', "missing_$param" ) if ( !defined( $self->query->param( $param ) ) ); |
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push @values, $self->query->param( $param ); |
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} |
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return @values; |
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} |
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=head2 add_routes |
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$self->add_routes( |
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[ $path_regex, $handler[, \@required_params] ], |
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... |
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); |
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Adds several routes, each described by an arrayref. |
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$path_regex should be a regex passed through qr//, describing which methods and |
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paths this route handles. Each route is tested in order, from the top down, so |
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put more specific handlers first. Also, the regex is tested on the request |
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method, plus the path. For instance, you might use the route [ qr'POST /', ... ] |
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to handle POST requests to your service. |
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$handler should be the name of a method in the current class. |
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If \@required_params is passed, each named parameter in it is tested to make sure the route matches. |
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No error is raised if one is missing; it simply tests the next route. If you would prefer to raise |
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an error, instead use C<require_params> inside your handler. |
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=cut |
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sub add_routes { |
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my $self = shift; |
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push @{ $self->{routes} }, @_; |
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} |
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=sub dispatch |
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$self->dispatch(); |
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Dispatches to the correct route for the current URL and parameters, or raises a 'no_handler' error. |
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$self->$handler is called with each matched group in $path_regex in its arguments. For |
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example, if your service is accessed at the path /blah/123, and you call |
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C<dispatch> with the route [ qr'GET /blah/(\d+)', ... ], your handler will be called |
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with the arguments '123'. The original C<CGI> object and cookie are available as C<$self->query> and C<$self->cookie>. |
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Returns the result of the matching handler. |
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=cut |
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sub dispatch { |
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my $self = shift; |
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my $path_info = $self->query->path_info || '/'; |
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ROUTE: foreach my $route ( @{ $self->{routes} } ) { |
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my ( $path, $handler, $params ) = @$route; |
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next unless ( my @match = ( ($self->query->request_method . ' ' . $path_info) =~ m,^$path$, ) ); |
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for my $param ( @{ $params || [] } ) { |
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next ROUTE if ( !defined( $self->query->param ( $param ) ) ); |
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} |
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$debug and warn "Using $handler for $path"; |
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return $self->$handler( @match ); |
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} |
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$self->croak( 'no_handler' ); |
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} |
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=sub run |
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$service->run(); |
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Runs the service. By default, calls authenticate, dispatch then output, but can be overridden. |
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=cut |
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sub run { |
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my ( $self ) = @_; |
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$self->authenticate; |
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my $result = $self->dispatch; |
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$self->output($result) if ($result); |
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} |
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1; |