Making APIs fun again!
Wrappi is a Framework to create API clients. The intention is to bring the best practices and standardize how API clients behave. It allows to create API clients in a declarative way improving readability and unifying the behavior. It abstracts complex operations like caching, retries, background requests and error handling.
Enjoy!
Add this line to your application's Gemfile:
gem 'wrappi'
And then execute:
$ bundle
Or install it yourself as:
$ gem install wrappi
Github example:
You can test this examples running bin/console
module GithubCLI
class Client < Wrappi::Client
setup do |config|
config.domain = 'https://api.github.com'
config.headers = {
'Content-Type' => 'application/json',
'Accept' => 'application/vnd.github.v3+json',
}
end
end
class User < Wrappi::Endpoint
client Client
verb :get
path "users/:username"
end
end
user = GithubCLI::User.new(username: 'arturictus')
user.success? # => true
user.error? # => false
user.status_code # => 200
user.body # => {"login"=>"arturictus", "id"=>1930175, ...}
The next behaviours are using #success?
method. You can override by redefining your own success?
The current #success?
is defined like this:
wrappi/endpoint.rb
def self.success?(request)
request.code < 300 && request.code >= 200
end
Overrride your own in Endpoint
class User < Wrappi::Endpoint
client Client
verb :get
path "users/:username"
def self.success?(request)
request.status == 200
end
end
GithubCLI::User.new(username: 'arturictus')
.on_success do |inst|
inst.status_code # => 200
inst.body # => {"login"=>"arturictus", "id"=>1930175, ...}
# do something useful
end.on_error do |inst|
puts "Error retrieving use"
end
If you just need to retrieve the body and handle the error response on your side
GithubCLI::User.body(username: 'arturictus') # => {"login"=>"arturictus", "id"=>1930175, ...}
GithubCLI::User.body(username: 'sdfsdfasdjfojaspdjfpsajdpfoijsapdofijsadf')
# => {"message"=>"Not Found", "documentation_url"=>"https://developer.github.com/v3/users/#get-a-single-user"}
returns false
if unsuccessful and instance if successful
if req = GithubCLI::User.call(username: 'arturictus')
req.body # => {"login"=>"arturictus", "id"=>1930175, ...}
else
# Handle error
end
Raises error if unsuccessful, returns instance if successful
begin
req = GithubCLI::User.call!(username: 'arturictus')
req.body # => {"login"=>"arturictus", "id"=>1930175, ...}
rescue => Wrappi::UnsuccessfulResponse
# Handle error or not
end
The error:
GithubCLI::User.call!(username: 'sdfsdfasdjfojaspdjfpsajdpfoijsapdofijsadf')
# Wrappi::UnsuccessfulResponse ()
# raw_body: {"message":"Not Found","documentation_url":"https://developer.github.com/v3/users/#get-a-single-user"}
# code: 404
# uri: https://api.github.com/users/sdfsdfasdjfojaspdjfpsajdpfoijsapdofijsadf
# success: false
Wrappi comes with a background Job out of the box. If you are in a Rails app the #async
method will queue a new job (< ActiveJob::Base
) that will make the request and trigger the async callback
after the request is made.
example:
class User < Wrappi::Endpoint
client Client
verb :get
path "users/:username"
async_callback do |opts|
# this will be called in background after the request is made
if success?
if opts[:create]
CreateUserService.call(body)
elsif opts[:update]
UpdateUserService.call(body)
end
end
end
end
# This will execute the request in a background job
Github::User.new(username: 'arturictus').async(create: true)
If you need to send options to your Job (the ::set
method) you can pass the key set
to the options.
Github::User.new(username: 'arturictus').async(create: true, set: { wait: 10.minutes })
You can enable cache per endpoint. It depends on ::success?
method to determine if it will be cached or nor.
Set the cache Handler in your client.
It must behave like Rails.cache
and respond to:
read([key])
write([key, value, options])
class Client < Wrappi::Client
setup do |config|
config.domain = 'https://api.github.com'
config.cache = Rails.cache
end
end
Enable cache in your endpoint.
class User < Wrappi::Endpoint
cache true # enable for endpoint
client Client
verb :get
path "users/:username"
end
user = User.new(username: 'arturictus')
user.response.class # => Wrappi::Response
user.flush
user.response.class # => Wrappi::CachedResponse
user.success? # => true
user.body # => {"login"=>"arturictus", "id"=>1930175, ...}
When cached the response will be a Wrappi::CachedResponse
. Wrappi::CachedResponse
behaves
like Wrappi::Response
that means you can use the endpoint in the same way as it was a non cached.
See cache_options
to fine tune your cache with expiration and other cache options.
You can use options to cache a single request.
class User < Wrappi::Endpoint
client Client
verb :get
path "users/:username"
end
User.new({username: 'arturictus'}, cache: true)
user.response.class # => Wrappi::Response
user.flush
user.response.class # => Wrappi::CachedResponse
user.success? # => true
user.body # => {"login"=>"arturictus", "id"=>1930175, ...}
Sometimes you want to retry if certain conditions affected your request.
This will retry if status code is not 200
class User < Wrappi::Endpoint
client Client
verb :get
path "users/:username"
retry_if do |response|
response.code != 200
end
end
Check more configuration options and examples for retry_if
and retry_options
below.
options:
Pass a second argument with options.
params = { username: 'arturictus' }
options = { options_in_my_instance: "yeah!" }
User.new(params, options)
Dynamic configurations:
All the configs in Endpoint
are evaluated at instance level except: around_request
and retry_if
because of their nature.
That allows you to fine tune the configuration at a instance level.
example:
Right now the default for cache
config is: proc { options[:cache] }
.
class User < Wrappi::Endpoint
client Client
verb :get
path "users/:username"
cache do
if input_params[:username] == 'arturictus'
false
else
options[:cache]
end
end
end
endpoint is a ruby class: 😮
class User < Wrappi::Endpoint
client Client
verb :get
path "users/:username"
cache do
cache?
end
def cache?
if input_params[:username] == 'arturictus'
false
else
options[:cache]
end
end
def parsed_response
@parsed_response ||= MyParser.new(body)
end
end
inheritance: All the configs will be inherited
class UserDetail < User
path "users/:username/detail"
end
Name | Type | Default | Required |
---|---|---|---|
domain | String | * | |
params | Hash | ||
headers | Hash | { 'Content-Type' => 'application/json', 'Accept' => 'application/json' } | |
async_handler | const | Wrappi::AsyncHandler | |
cache | const | ||
logger | Logger | Logger.new(STDOUT) | |
timeout | Hash | { write: 9, connect: 9, read: 9 } | |
use_ssl_context | Boolean | false | |
ssl_context | OpenSSL::SSL::SSLContext | ||
basic_auth | Hash (keys: user, pass) |
Name | Type | Default | Required |
---|---|---|---|
client | Wrappi::Client | * | |
path | String | * | |
verb | Symbol | :get | * |
default_params | Hash or block -> Hash |
{} | |
headers | Hash or block -> Hash |
proc { client.headers } | |
basic_auth | Hash (keys: user, pass) or block -> Hash |
proc { client.basic_auth } | |
follow_redirects | Boolean or block -> Boolean |
true | |
body_type | Symbol, one of: :json,:form,:body | :json | |
cache | Boolean or block -> Boolean |
proc { options[:cache] } | |
cache_options | block -> Hash | ||
retry_if | block | ||
retry_options | Hash or block -> Hash |
||
around_request | block | ||
async_callback | block |
Is the main configuration for your service.
It holds the common configuration for all the endpoints (Wrappi::Endpoint
).
config.domain = 'https://api.github.com'
params: Set global params for all the Endpoints
.
This is a great place to put the api_key
.
config.params = { "api_key" => "asdfasdfoerkwlejrwer" }
default: {}
logger: Set your logger.
default: Logger.new(STDOUT)
config.logger = Rails.logger
headers: Headers for all the endpoints. Format, Authentication.
default:
{ 'Content-Type' => 'application/json', 'Accept' => 'application/json' }
config.headers = {
"Content-Type" => "application/json",
"Accept' => 'application/json",
"Auth-Token" => "verysecret"
}
async_handler: If you are not in Rails app or you have another background mechanism in place
you can configure here how the requests will be send to the background.
When #async
is called on an Endpoint instance the async_handler
const will be called with:
current endpoint instance (self
) and the options passed to the async method.
class MyAsyncHandler
def self.call(endpoint, opts)
# send to background
end
end
class Client < Wrappi::Client
setup do |config|
config.domain = 'https://api.github.com'
config.async_handler = MyAsyncHandler
end
end
endpoint_inst.async(this_opts_are_for_the_handler: true)
timeout: Set your specific timout. When you set timeout it will be merged with defaults.
default: { write: 9, connect: 9, read: 9 }
class Client < Wrappi::Client
setup do |config|
config.domain = 'https://api.github.com'
config.timeout = { read: 3 }
end
end
Client.timeout # => { write: 9, connect: 9, read: 3 }
use_ssl_context: It has to be set to true
for using the ssl_context
default: false
ssl_context: If you need to set an ssl_context.
default: nil
config.ssl_context = OpenSSL::SSL::SSLContext.new.tap do |ctx|
ctx.verify_mode = OpenSSL::SSL::VERIFY_NONE
end
client: Wrappi::Client
class
client MyClient
path: The path to the resource. You can use doted notation and they will be interpolated with the params
class MyEndpoint < Wrappi::Endpoint
client MyClient
verb :get
path "/users/:id"
end
endpoint = MyEndpoint.new(id: "the_id", other: "foo")
endpoint.url_with_params #=> "http://domain.com/users/the_id?other=foo"
endpoint.url #=> "http://domain.com/users/the_id"
endpoint.consummated_params #=> {"other"=>"foo"}
Notice how interpolated params are removed from the query or the body
verb:
default: :get
:get
:post
:delete
:put
default_params: Default params for the request. This params will be added to all the instances unless you override them.
default: {}
class MyEndpoint < Wrappi::Endpoint
client MyClient
verb :get
path "/users/:id"
default_params do
{ other: "bar", foo: "foo" }
end
end
endpoint = MyEndpoint.new(id: "the_id", other: "foo")
endpoint.consummated_params #=> {"other"=>"foo","foo" => "foo" }
headers: You can modify the client headers here. Notice that if you want to use the client headers as well you will have to merge them.
default: proc { client.headers }
class MyEndpoint < Wrappi::Endpoint
client MyClient
verb :get
path "/users"
headers do
client.headers #=> { 'Content-Type' => 'application/json', 'Accept' => 'application/json' }
client.headers.merge('Agent' => 'wrappi')
end
end
endpoint = MyEndpoint.new()
endpoint.headers #=> { 'Agent' => 'wrappi', 'Content-Type' => 'application/json', 'Accept' => 'application/json'}
basic_auth: If your endpoint requires basic_auth here is the place. keys
have to be: user
and pass
.
default: nil
basic_auth do
{ user: 'wrappi', pass: 'secret'}
end
follow_redirects: If the request responds with a redirection it will follow them.
default: true
body_type: Body type.
default: :json
async_callback: When request is executed in the background with #async(opts = {})
this
callback will be called with this opts as and argument in the block.
The block is executed in the endpoint instance. You can access to all the methods in Endpoint.
default: proc {}
async_callback do |opts|
if success?
MyCreationService.call(body) if opts[:create]
end
end
MyEndpoint.new().async(create: true)
This configs allows you fine tune your request adding middleware, retries and cache. The are executed in this nested stack:
cache
|- retry
|- around_request
Check specs for more examples.
cache: Cache the request if successful.
default: proc { options[:cache] }
cache_options: Options for the cache
to receive on write
cache_options do
{ expires_in: 12, another_opt: true }
end
default: {}
retry_if: Block to evaluate if request has to be retried. In the block are
yielded Response
instance. If the block returns true
the request will be retried.
retry_if do |response|
response.status != 200 # => true or false
end
Use case:
We have a service that returns an aggregation of hotels available to book for a city. The service will start the aggregation in the background and will return 200
if the aggregation is completed if the aggregation is not completed will return 201
making us know that we should call again to retrieve all the data. This behavior only occurs if we pass the param: onlyIfComplete
.
retry_if do |response, endpoint|
endpoint.consummated_params["onlyIfComplete"] &&
response.status_code == 201
end
Notice that this block will never be executed if an error occur (like timeouts). For retrying on errors use the retry_options
retry_options: We are using the great gem retryable to accomplish this behavior. Check the documentation for fine tuning. I just paste some examples for convenience.
retry_options do
{ tries: 5, on: [ArgumentError, Wrappi::TimeoutError] } # or
{ tries: :infinite, sleep: 0 }
end
request.call
. around_request do |request, endpoint|
endpoint.logger.info("making a request to #{endpoint.url} with params: #{endpoint.consummated_params}")
request.call # IMPORTANT
endpoint.logger.info("response status is: #{request.status_code}")
end
Wrappi is designed to be able to build HTTP client gems with it.
module GithubCLI
class Client < Wrappi::Client
setup do |config|
config.domain = 'https://api.github.com'
config.headers = {
'Content-Type' => 'application/json',
'Accept' => 'application/vnd.github.v3+json',
}
end
class << self
attr_accessor :my_custom_config
end
end
def self.setup
yield(Client)
end
class Endpoint < Wrappi::Endpoint
client Client
end
class User < Endpoint
verb :get
path "users/:username"
end
def self.user(params, opts = {})
User.new(params, opts)
end
end
user = GithubCLI.user(username: 'arturictus')
user.success?
Once you created a gem Wrappi allows to parent projects to customize endpoints without having to change the gem's code.
example customizing GithubCLI::User
GithubCLI::User.setup do
cache true
async_callback do |opts|
if success?
# do something
end
end
end
Example customizing all the Endpoints, adding loging to all the requests and changing client depending of enviroment:
GithubCLI::Endpoint.setup do
client do
if ENV['production']
GithubCLI::Client
else
GithubCLI::MyStagingClient
end
end
around_request do |request, endpoint|
endpoint.logger.info("making a request to #{endpoint.url} with params: #{endpoint.consummated_params}")
request.call # IMPORTANT
endpoint.logger.info("response status is: #{request.status_code}")
end
end
In ruby there are many ruby clients an everyone has an opinion of which one is the best. Every new API client that you install in your project will install a different HTTP client adding redundant and unnecessary dependencies in your project. That's why Wrappi is designed to be HTTP client agnostic. Right now is implemented with HTTP gem (my favorite) but all the logic is decoupled from the HTTP client.
All the configuration, metadata and logic to build the request is hold by an instance of Endpoint. Allowing to create adapters that translates this processed metadata to the target HTTP client.
Tests are HTTP client agnostic. To help the development of these adapters and probe the reliability of the gem most of the test are run against a Rails application. All the tests that probe an HTTP call are running this HTTP call against a local server making all test End To End and again, HTTP client agnostic.
Right now is not designed the system to change HTTP clients via configuration but if you are interested to implement one let me know and we will figure out the way.
After checking out the repo, run bin/setup
to install dependencies.
bin/dev_server
This will run a rails server. The test are running against it.
bundle exec rspec
You can also run bin/console
for an interactive prompt that will allow you to experiment.
Run dummy server with docker:
docker build -t wrappi/dummy -f spec/dummy/Dockerfile .
docker run -d -p 127.0.0.1:9873:9873 wrappy/dummy /bin/sh -c "bin/rails server -b 0.0.0.0 -p 9873"
Try:
curl 127.0.0.1:9873 #=> {"controller":"pages","action":"show_body"}
Bug reports and pull requests are welcome on GitHub at https://github.com/arturictus/wrappi. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
The gem is available as open source under the terms of the MIT License.