NAME

WebService::GData - Google data protocol v2.

SYNOPSIS

package WebService::MyService;
use WebService::GData;#strict/warnings turned on
use base 'WebService::GData';

#this is the base implementation of the __init method in WebService::GData
#it is call when new() is used. only overwrite it if necessary.

sub __init {
    my ($this,%params) = @_;
    while(my ($prop,$val)=each %params){
        $this->{$prop}=$val;
    }
}


WebService::GData::install_in_package([qw(firstname lastname age gender)],sub {
        my $func = shift;
        return sub {
            my $this = shift;
            return $this->{$func};
        }
});

#the above is equal to writing these simple getters:

#sub firstname {
#    my $this = shift;
#    return $this->{firstname};
#}

#sub lastname {
#    my $this = shift;
#    return $this->{lastname};
#}

#sub age {
#    my $this = shift;
#    return $this->{age};
#}  

#sub gender {
#    my $this = shift;
#    return $this->{gender};
#}  

1;


use WebService::MyService; 

my $object = new WebService::MyService(name=>'test');

$object->name;#test

#__set and __get are used to create automaticly getters and setters
$object->age(24);
$object->age();#24 
$object->{age};#24

DESCRIPTION

WebService::GData module intends to implement the Google Data protocol and implements some services that use this protocol, like YouTube.

This package is a blueprint that most packages in this module inherit from. It offers a simple hashed based object creation mechanism via the word new.

If you want to pock into the instance, it's easy but everything that is not documented should be considered private. If you play around with undocumented properties/methods and that it changes,upgrading to the new version with all the extra new killer features will be very hard to do.

so...

dont.

As an example, the following classes extend WebService::GData to implement their feature:

WebService::GData::Base

Implements the base get/post/insert/update/delete methods via HTTP for the Google data protocol.

WebService::GData::ClientLogin

Implements the ClientLogin authorization system.

WebService::GData::Error

Represents a Google data protocol Error.

WebService::GData::Query

Implements the basic query parameters and create a query string.

WebService::GData::Feed

Represents the basic tags found in a Atom Feed (JSON format).

A service in progress:

WebService::GData::YouTube

Implements parts of the YouTube API .

CONSTRUCTOR

new

Takes an hash which keys will be attached to the instance, $this. You can also use install_in_package() to create setters/getters or simply let the methods been redispatched automaticly.

Parameters

parameters:Hash

Returns

WebService::GData

Example:

    my $object = new WebService::GData(firstname=>'doe',lastname=>'john',age=>'123');

    $object->{firstname};#doe
    $object->firstname;#doe
    $object->firstname('billy');
    $object->firstname;#billy
	

METHODS

__init

This method is called by the constructor new(). This function receives the parameters set in new() and assign the key/values pairs to the instance. You should overwrite it and add your own logic if necessary.

Default implementation:

sub __init {
    my ($this,%params) = @_;
    while(my ($prop,$val)=each %params){
        $this->{$prop}=$val;
    }
}

OVERLOAD

__to_string

Overload the stringification quotes and return the object. You should overwrite it to create a specific output (Dump the object, display a readable representation...).

equal

Overload the comparison "==" by checking that boch objects are hosted in the same memory slot.

AUTOLOAD

Calls to undefined methods on an instance are catched and dispatch to __get if the call does not contain any parameter or __set if parameters exist. You can overwrite these two methods in your package to meet your naming needs. For example, when you call $instance->dont_exist, you might want to look into $instance->{__DONT_EXIST} instead of the default $instance->{dont_exist}.

__get

This method catches all calls to undefined methods to which no parameters are passed. If you call $instance->unknown_method, the __get method will return $instance->{unknown_method} by default. The __get method gets the instance and the name of the function has parameters.

Below is the default implementation:

sub __get { my ($this,$func) = @_; return $this->{$func}; }

__set

This method catches all calls to undefined methods to which parameters are passed. If you call $instance->unknown_method($val,$val2), the __set method will set the parameters to $instance->{unknown_method} by default. When several parameters are passed, they are saved as an array reference. The __set method gets the instance,the name of the function and the parameters as its own arguments.

Below is the default implementation:

sub __set { my ($this,$func,@args) = @_; $this->{$func}= @args == 1 ? $args[0] : \@args; return $this; }

SUBS

install_in_package

Install in the package the methods/subs specified. Mostly use to avoid writting boiler plate getter/setter methods and a bit more efficient than AUTOLOAD methods as they are installed directly into the package so it will not climb up a function chain call.

Parameters

subnames:ArrayRef - Should list the name of the methods you want to install in the package.

callback:Sub - The callback will receive the name of the function. This callback should itself send back a function.

package_name:Scalar (optional) - Add functions at distance by specifying an other module.

Returns

void

Example:

    package Basic::User;
    use WebService::GData;
    use base 'WebService::GData';
    
    #install simple setters; it could also be setter/getters
	
    WebService::GData::install_in_package([qw(firstname lastname age gender)],sub {
            my $func = shift;#firstname then lastname then age...
            return sub {
                my $this = shift;
                return $this->{$func};
            }
    });

    1;

    #in user code:

    my $user = new Basic::User(firstname=>'doe',lastname=>'john',age=>100,gender=>'need_confirmation');

    $user->age;#100
    $user->firstname;#doe
	

private

Create a method that is private to the package. Calling a private function from outside of the package will throw an error.

You can import the private method:

use WebService::GData 'private';

Parameters

function_name_with_sub:Hash - Accept an hash which key is the function name and value a sub.

Returns

void

Throws

error:RefHash - an hash containing the code: 'forbidden_access' and the content:'private method called outside of its package'.

Example:

    package Basic::User;
    use WebService::GData 'private';
    use base 'WebService::GData';
    
    private my_secret_method => sub {
		
    };  #note the comma

    1;

    #in user code:
	
    my $user = new Basic::User();

    $user->my_secret_method();#throw an error
	
    eval {
        $user->my_secret_method();
    };
    if(my $error = $@){
        #$error->{code};
        #$error->{content};
    }
	

disable

Overwrite a method so that it does nothing... Some namespaces inherit from functionalities that are not required. The functions will still be available but will just return the instance.

Parameters

functions:ArrayRef - array reference containing the functions to disable

package:Scalar* - (optional) By default it uses the package in which it is called but you can specify a package.

Returns

void

Example:

    package Basic::User;
    use WebService::GData;
    use base 'WebService::GData::Feed';
    
    WebService::GData::disable([qw(etag title)]);

    1;

    #in user code:
	
    my $user = new Basic::User();

    $user->etag("ddd")->title("dddd");#does nothing at all

	

BUGS AND LIMITATIONS

If you do me the favor to _use_ this module and find a bug, please email me i will try to do my best to fix it (patches welcome)!

AUTHOR

shiriru <shirirulestheworld[arobas]gmail.com>

LICENSE

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

cpanm WebService::GData

perl -MCPAN -e shell
install WebService::GData