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API-Client-0.04
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/ API::Client

NAME

API::Client - General-Purpose API Client Abstraction

VERSION

version 0.04

SYNOPSIS

    use API::Client;

    my $client = API::Client->new(url => "https://api.example.com");

    $client->debug(1);
    $client->fatal(1);

    my $resource = $client->resource;
    my $results  = $resource->fetch;

    # after some introspection

    $resource->update(...);

DESCRIPTION

This distribution provides an API client abstraction for rapidly developing client to interact with web services. Although this module can be used to interact with APIs directly, API::Client was designed to be consumed (subclassed) by higher-level purpose-specific API client code.

THIN CLIENT

The thin api-client library is advantageous as it has complete API coverage and can easily adapt to changes in the API with minimal effort. As a thin-client library, this module does not map specific HTTP requests to specific routines, nor does it provide parameter validation, pagination, or other conventions found in typical API client implementations; Instead, it simply provides a simple and consistent mechanism for dynamically generating HTTP requests. Additionally, this module has support for debugging and retrying API calls as well as throwing exceptions when 4xx and 5xx server response codes are returned.

Building

    my $user = $client->users('c09e91a');

    $user->action; # GET /users/c09e91a
    $user->action('head'); # HEAD /users/c09e91a
    $user->action('patch'); # PATCH /users/c09e91a

Building up an HTTP request object is extremely easy, simply call method names which correspond to the API's path segments in the resource you wish to execute a request against. This module uses autoloading and returns a new instance with each method call. The following is the equivalent:

Chaining

    my $user = $client->resource('users', 'c09e91a');

    # or

    my $users = $client->users;
    my $user  = $users->resource('c09e91a');

    # then

    $user->action('put', %args); # PUT /users/c09e91a

Because each call returns a new API instance configured with a resource locator based on the supplied parameters, reuse and request isolation are made simple, i.e., you will only need to configure the client once in your application.

Fetching

    my $users = $client->users;

    # query-string parameters

    $users->fetch( query => { ... } );

    # equivalent to

    my $users = $client->resource('users');

    $users->action( get => ( query => { ... } ) );

This example illustrates how you might fetch an API resource.

Creating

    my $users = $client->users;

    # content-body parameters

    $users->create( data => { ... } );

    # query-string parameters

    $users->create( query => { ... } );

    # equivalent to

    $client->resource('users')->action(
        post => ( query => { ... }, data => { ... } )
    );

This example illustrates how you might create a new API resource.

Updating

    my $users = $client->users;
    my $user  = $users->resource('c09e91a');

    # content-body parameters

    $user->update( data => { ... } );

    # query-string parameters

    $user->update( query => { ... } );

    # or

    my $user = $client->users('c09e91a');

    $user->update(...);

    # equivalent to

    $client->resource('users')->action(
        put => ( query => { ... }, data => { ... } )
    );

This example illustrates how you might update a new API resource.

Deleting

    my $users = $client->users;
    my $user  = $users->resource('c09e91a');

    # content-body parameters

    $user->delete( data => { ... } );

    # query-string parameters

    $user->delete( query => { ... } );

    # or

    my $user = $client->users('c09e91a');

    $user->delete(...);

    # equivalent to

    $client->resource('users')->action(
        delete => ( query => { ... }, data => { ... } )
    );

This example illustrates how you might delete an API resource.

Transacting

    my $users = $client->resource('users', 'c09e91a');

    my ($results, $transaction) = $users->action( ... );

    my $request  = $transaction->req;
    my $response = $transaction->res;

    my $headers;

    $headers = $request->headers;
    $headers = $response->headers;

    # etc

This example illustrates how you can access the transaction object used to represent and process the HTTP transaction.

Casing

    $client->casing('lowercase');

    my $settings = $client->users('c09e91a')->profile_settings;

    # given casing as 'lowercase'
    $settings->fetch( ... ); # GET /users/c09e91a/profile_settings

    # given casing as 'uppercase'
    $settings->fetch( ... ); # GET /USERS/C09E91A/PROFILE_SETTINGS

    # given casing as 'camelcase'
    $settings->fetch( ... ); # GET /users/c09e91a/profileSettings

    # given casing as 'snakecase'
    $settings->fetch( ... ); # GET /users/c09e91a/profileSettings

    # given casing as 'pascalcase'
    $settings->fetch( ... ); # GET /Users/c09e91a/ProfileSettings

This example illustrates how you can configure the client to automatically handle the casing of path segments while continuing to use lowercase-userscore separated string in your code. This is useful when interacting with an API that uses convetions foreign to that of your codebase.

ATTRIBUTES

casing

    $client->casing;
    $client->casing('lowercase');

The casing attribute should be set to either lowercase, snakecase, camelcase, pascalcase, or uppercase, which determines how URL segments should be formatted.

credentials

    $client->credentials;
    $client->credentials(API::Client::Credentials->new(...));

The credentials attribute sets the pre-configured Credentials object that, if defined, will be used to modify the Transaction object to include authentication credentials. This attribute expects an object derived from the API::Client::Credentials class.

identifier

    $client->identifier;
    $client->identifier('API::Client (Perl)');

The identifier attribute should be set to a string that identifies your application.

debug

    $client->debug;
    $client->debug(1);

The debug attribute if true prints HTTP requests and responses to standard out.

fatal

    $client->fatal;
    $client->fatal(1);

The fatal attribute if true promotes 4xx and 5xx server response codes to exceptions, a API::Client::Exception object.

retries

    $client->retries;
    $client->retries(10);

The retries attribute determines how many times an HTTP request should be retried if a 4xx or 5xx response is received. This attribute defaults to 0.

timeout

    $client->timeout;
    $client->timeout(5);

The timeout attribute determines how long an HTTP connection should be kept alive. This attribute defaults to 10.

url

    $client->url;
    $client->url(Mojo::URL->new('https://api.example.com'));

The url attribute sets the base/pre-configured URL object that will be used in all HTTP requests. This attribute expects a Mojo::URL object.

user_agent

    $client->user_agent;
    $client->user_agent(Mojo::UserAgent->new);

The user_agent attribute sets the pre-configured UserAgent object that will be used in all HTTP requests. This attribute expects a Mojo::UserAgent object.

METHODS

action

    my $result = $client->action($verb, %args);

    # e.g.

    $client->action('head', %args);    # HEAD request
    $client->action('options', %args); # OPTIONS request
    $client->action('patch', %args);   # PATCH request

The action method issues a request to the API resource represented by the object. The first parameter will be used as the HTTP request method. The arguments, expected to be a list of key/value pairs, will be included in the request if the key is either data or query.

create

    my $results = $client->create(%args);

    # or

    $client->POST(%args);

The create method issues a POST request to the API resource represented by the object. The arguments, expected to be a list of key/value pairs, will be included in the request if the key is either data or query.

delete

    my $results = $client->delete(%args);

    # or

    $client->DELETE(%args);

The delete method issues a DELETE request to the API resource represented by the object. The arguments, expected to be a list of key/value pairs, will be included in the request if the key is either data or query.

fetch

    my $results = $client->fetch(%args);

    # or

    $client->GET(%args);

The fetch method issues a GET request to the API resource represented by the object. The arguments, expected to be a list of key/value pairs, will be included in the request if the key is either data or query.

update

    my $results = $client->update(%args);

    # or

    $client->PUT(%args);

The update method issues a PUT request to the API resource represented by the object. The arguments, expected to be a list of key/value pairs, will be included in the request if the key is either data or query.

AUTHOR

Al Newkirk <anewkirk@ana.io>

COPYRIGHT AND LICENSE

This software is copyright (c) 2014 by Al Newkirk.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.