class OAuth2::Client
inherits Reference

An OAuth2 client.

For a quick example of how to authenticate an HTTP::Client with OAuth2 if you already have an access token, check the OAuth2 module description.

This class also provides methods to build authorize URIs and get access tokens with different methods, as specified by RFC 6749.

Example

require "oauth2"

client_id = "some_client_id"
client_secret = "some_client_secret"
redirect_uri = "http://some.callback"

# Create oauth client, optionally pass custom URIs if needed,
# if the authorize or token URIs are not the standard ones
# (they can also be absolute URLs)
oauth2_client = OAuth2::Client.new("api.example.com", client_id, client_secret,
  redirect_uri: redirect_uri)

# Build an authorize URI
authorize_uri = oauth2_client.get_authorize_uri

# Redirect the user to `authorize_uri`...
#
# ...
#
# When http://some.callback is hit, once the user authorized the access,
# we resume our logic to finally get an access token. The callback URL
# should receive an `authorization_code` parameter that we need to use.
authorization_code = request.params["code"]

# Get the access token
access_token = oauth2_client.get_access_token_using_authorization_code(authorization_code)

# Probably save the access token for reuse... This can be done
# with `to_json` and `from_json`.

# Use the token to authenticate an HTTP::Client
client = HTTP::Client.new("api.example.com", tls: true)
access_token.authenticate(client)

# And do requests as usual
client.get "/some_path"

# If the token expires, we can refresh it
new_access_token = oauth2_client.get_access_token_using_refresh_token(access_token.refresh_token)

You can also use an OAuth2::Session to automatically refresh expired tokens before each request.

Class methods

.new(host : String, client_id : String, client_secret : String, port : Int32? = nil, scheme = "https", authorize_uri = "/oauth2/authorize", token_uri = "/oauth2/token", redirect_uri : String? = nil, auth_scheme : AuthScheme = :http_basic)

Creates an OAuth client.

Any or all of the customizable URIs authorize_uri and token_uri can be relative or absolute. If they are relative, the given host, port and scheme will be used. If they are absolute, the absolute URL will be used.

As per https://tools.ietf.org/html/rfc6749#section-2.3.1, AuthScheme::HTTPBasic is the default auth_scheme (the mechanism used to transmit the client credentials to the server). AuthScheme::RequestBody should only be used if the server does not support HTTP Basic.

View source

Methods

#get_access_token_using_authorization_code(authorization_code : String) : AccessToken

Gets an access token using an authorization code, as specified by RFC 6749, Section 4.1.3.

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#get_access_token_using_client_credentials(scope = nil) : AccessToken

Gets an access token using client credentials, as specified by RFC 6749, Section 4.4.2.

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#get_access_token_using_refresh_token(refresh_token, scope = nil) : AccessToken

Gets an access token using a refresh token, as specified by RFC 6749, Section 6.

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#get_access_token_using_resource_owner_credentials(username : String, password : String, scope = nil) : AccessToken

Gets an access token using the resource owner credentials, as specified by RFC 6749, Section 4.3.2.

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#get_authorize_uri(scope = nil, state = nil) : String

Builds an authorize URI, as specified by RFC 6749, Section 4.1.1.

View source

#get_authorize_uri(scope = nil, state = nil, &block : URI::Params::Builder -> ) : String

Builds an authorize URI, as specified by RFC 6749, Section 4.1.1.

Yields an URI::Params::Builder to add extra parameters other than those defined by the standard.

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#http_client : HTTP::Client

Returns the HTTP::Client to use with this client.

By default, this returns a new instance every time. To reuse the same instance, one can be assigned with #http_client=.

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#http_client=(http_client : HTTP::Client?)

Sets the HTTP::Client to use with this client.

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