twitter_oauth - Send an authorized OAuth request to the Twitter REST API in Lasso 9

Read the article twitter_oauth - Send an authorized OAuth request to the Twitter REST API in Lasso 9.

Introduction

Twitter frequently changes its API, authentication requirements, and its policies. In turn developers need to adjust to the changing conditions. The twitter_oauth type is the latest iteration of playing catch-up.

Up until January 24, 2014, using Twitter from your web application was fairly easy, thanks to Jason Huck's twitter custom type for Lasso 8. It used basic authentication with a username and password. Then Twitter shut off basic authentication on August 16, 2010, replacing it with OAuth. Developers were forced to use OAuth or not use the Twitter REST API at all.

Many other languages supported the Twitter API using OAuth with their libraries, but that meant Lasso developers would have to go through os_process or sys_process to interact with that language. No OAuth library existed for Lasso.

Fortunately SuperTweet provided its OAuth proxy service for non-commercial use so that developers could continue to use the Twitter API with only a username and password, just like old times. Jason Huck quickly followed by updating the twitter custom type to use the SuperTweet proxy service. But then Twitter suspended its access on January 24, 2014. If developers wanted to continue using a username and password to interact with the Twitter API, then they had to install their own proxy service.

Prior to SuperTweet's suspension, Tim Taplin released his oAuth_lib for lasso on September 9, 2013. Lasso developers now had a method to authenticate with the Twitter API using OAuth, but implementation details were left to the developer.

A client hired me to implement those complicated details but provide a simple interface. Among its many features, the twitter_oauth type can retrieve recent tweets, which can be formatted using the client's own design instead of the widgets that Twitter provides for non-programmers.

twitter_oauth is a type in Lasso 9 that allows a developer to send an authorized OAuth request to the Twitter REST API, and returns the response in JSON format. You can hire me or send me a GitTip to create a version for Lasso 8, or you can create your own version and contribute it to the project. I have released the code under a free and open source software license.

Description

twitter_oauth is a Lasso 9 type that allows a developer to send an authorized OAuth request to the Twitter REST API, and returns the response in JSON format.

Demo

Sorry, no demo is available at this time.

Usage

Parameters

twitter_oauth accepts three parameters.

httpmethod accepts a string object. It represents the HTTP method that shall be used in the request. Supported values are GET and POST. This parameter is optional.
baseurl accepts a string object. It represents the URL to which the request shall be sent to the Twitter REST API. Any value listed in the Twitter REST API v1.1 Resources is supported. This parameter is optional.
additional accepts an array object containing pairs. It represents additional parameters as key/value pairs that can be sent to the Twitter REST API. Any value pertaining to the supplied baseurl is supported. See A field guide to Twitter Platform objects for details. This parameter is optional.

Methods

twitter_oauth has three public setter methods with names corresponding to the three parameters listed above, and one public method to send an HTTP request to the Twitter REST API.

httpmethod sets the HTTP method.
baseurl sets the base URL.
additional sets additional parameters to send in the HTTP request.
makeHTTPRequest makes an HTTP request to the Twitter REST API using the aforementioned parameters, and returns the response in JSON format.

Examples

// initialize the type to retrieve the three most recent tweets from
// the user's timeline
local(t) = twitter_oauth(
    'get',
    'https://api.twitter.com/1.1/statuses/user_timeline.json',
    array(
        'screen_name' = 'steve_piercy',
        'count' = '3',
        'exclude_replies' = 'true',
    )
)

// make the request, deserialize the response, and store the result
local(r) = json_deserialize(#t->makeHTTPRequest)
// format the response
local(f) = string
with i in #r do => {
    #f->append('<p>')
    #f->append(#i->find('text')->
        replace(
            regexp('(https?://\\S.+?)(\\s|$)'),
                '<a href="\\1">\\1</a>\\2'
        )&
        replace(
            regexp('@([a-zA-Z0-9_]{1,15})'),
            '<a href="https://twitter.com/\\1">@\\1</a>'
        )&
        replace(
            regexp('#([a-zA-Z0-9_]{1,15})'),
                '<a href="https://twitter.com/hashtag/\\1">#\\1</a>'
        )&
    )
    #f->append('</p>\n')
}
'<textarea cols="100" rows="20">' + #f + '</textarea>'

=>
<textarea cols="100" rows="20">
<p>RT <a href="https://twitter.com/iElectric">@iElectric</a>: Introducing Multi File Upload for Substance D by <a href="https://twitter.com/reebalazs">@reebalazs</a> <a href="http://t.co/N6eUoSBS4s">http://t.co/N6eUoSBS4s</a></p>
<p>Testing new Twitter oAuth type for Lasso</p>
<p>Pretty print JSON with <a href="https://twitter.com/BBEdit">@BBEdit</a> and Python <a href="http://t.co/EhCg67GPAV">http://t.co/EhCg67GPAV</a></p>
</textarea>

Alternatively one could initialize a twitter_oauth object, then set its parameters, and finally make the request.

// initialize the type
local(t) = twitter_oauth()
// set parameters to retrieve the three most recent tweets from the user's timeline
#t->httpmethod = 'get'
#t->baseurl = 'https://api.twitter.com/1.1/statuses/user_timeline.json'
#t->additional = array(
        'screen_name' = 'steve_piercy',
        'count' = '4',
        'exclude_replies' = 'true',
    )
// proceed with the rest of the code

Another common method is to update a user's status or send a tweet.

local(t) = twitter_oauth(
    'post',
    'https://api.twitter.com/1.1/statuses/update.json',
    array(
        'status' = 'Testing new Twitter oAuth type for Lasso'
    )
)

Installation and Requirements

A Twitter account with a verified email address is required.

A Twitter Application is required. The Twitter Application Management provides developers a way to manage their Twitter apps, including obtaining the required configuration settings to use in the twitter_oauth type.

This type requires sp_string_random. Download or clone its repository.

Download or clone the twitter_oauth type.

Edit the file twitter_oauth.lasso to use your Twitter Application configuration settings, and save.

Install both files sp_string_random.lasso and twitter_oauth.lasso where you think is best. Either place it in your Lasso Server's or Instances's LassoStartup directory, restarting the appropriate scope as needed. I recommend Lasso Instance LassoStartup.

Notes

The project twitter_oauth and its source files are hosted on GitHub.

Twitter REST API v1.1 Resources

A field guide to Twitter Platform objects

Exploring the Twitter API with an online API tester.

While writing this type, I referred a great deal to Twitter API documentation on Creating a signature and Authorizing a request.

stevepiercy / twitter_oauth