Tanshuku

Tanshuku is a simple and small Rails engine that makes it easier to shorten URLs.

Key Features

• Generates a unique key for a URL.
  • The uniqueness is ensured at database level.
• Creates no additional shortened URL record if the given URL has already been shortened.
  • You can create an additional record for the same URL with using a different namespace from existing records’.
  • Checks its existence considering the performance.
• Provides a Rails controller and action for finding a shortened URL record and redirecting to its original, i.e., non-shortened, URL.
  • The redirection is done with 301 HTTP status.

Usage

1. Mount Tanshuku::Engine

For example, the following code generates a routing GET `/t/:key` to `Tanshuku::UrlsController#show`. When your Rails app receives a request to /t/abcdefghij0123456789, Tanshuku::UrlsController#show will be called and a Tanshuku::Url record with a key abcdefghij0123456789 will be found. Then the request will be redirected to the Tanshuku::Url record’s original URL.

# config/routes.rb
Rails.application.routes.draw do
  mount Tanshuku::Engine, at: "/t"
end

Note: You can customize the path /t as you like.

2. Configure Tanshuku (Optional)

Note: This step is optional.

Note: An initializer file for configuration can be generated by bin/rails generate tanshuku:install. See the “Installation” section below for more information.

Note: Mutating a Tanshuku::Configuration object is thread-unsafe. It is recommended to use Tanshuku.configure for configuration.

config.default_url_options

Tanshuku uses configured config.default_url_options when generating shortened URLs.

Default value is {}.

The following example means that the configured host and protocol are used. Shortened URLs will be like https://example.com/t/abcdefghij0123456789.

# config/initializers/tanshuku.rb
Tanshuku.configure do |config|
  config.default_url_options = { host: "example.com", protocol: :https }
end

config.exception_reporter

If an exception occurs when shortening a URL, Tanshuku reports it with configured config.exception_reporter object.

Default value is Tanshuku::Configuration::DefaultExceptionReporter. It logs the exception and the original URL with Rails.logger.warn.

Value of config.exception_reporter should respond to #call with keyword arguments exception: and original_url:.

The following example means that an exception and a URL will be reported to Sentry.

# config/initializers/tanshuku.rb
Tanshuku.configure do |config|
  config.exception_reporter =
    lambda { |exception:, original_url:|
      Sentry.capture_exception(exception, tags: { original_url: })
    }
end

More information

cf. Tanshuku::Configuration’s API documentation

3. Generate shortened URLs

Basic cases

You can generate a shortened URL with Tanshuku::Url.shorten. For example:

Tanshuku::Url.shorten("https://google.com/")  #=> "https://example.com/t/abcdefghij0123456789"

config.default_url_options is used for the shortened URL.

Note: If a Tanshuku::Url record for the given URL already exists, no additional record will be created and always the existing record is used.

# When no record exists for "https://google.com/", a new record will be created.
Tanshuku::Url.shorten("https://google.com/")  #=> "https://example.com/t/abcde0123456789fghij"

# When a record already exists for "https://google.com/", no additional record will be created.
Tanshuku::Url.shorten("https://google.com/")  #=> "https://example.com/t/abcde0123456789fghij"
Tanshuku::Url.shorten("https://google.com/")  #=> "https://example.com/t/abcde0123456789fghij"
Tanshuku::Url.shorten("https://google.com/")  #=> "https://example.com/t/abcde0123456789fghij"

Shortening a URL with ad hoc URL options

You can specify URL options to Tanshuku::Url.shorten. For example:

Tanshuku::Url.shorten("https://google.com/", url_options: { host: "verycool.example.com" })
#=> "https://verycool.example.com/t/0123456789abcdefghij"

Tanshuku::Url.shorten("https://google.com/", url_options: { protocol: :http })
#=> "http://example.com/t/abcde01234fghij56789"

Shortening a URL with a namespace

You can create additional records for the same URL with specifying a namespace.

# When no record exists for “https://google.com/”, a new record will be created.
Tanshuku::Url.shorten("https://google.com/")  #=> "https://example.com/t/abc012def345ghi678j9"

# Even when a record already exists for “https://google.com/”, an additional record will be created if namespace is
# specified.
Tanshuku::Url.shorten("https://google.com/", namespace: "a")  #=> "https://example.com/t/ab01cd23ef45gh67ij89"
Tanshuku::Url.shorten("https://google.com/", namespace: "b")  #=> "https://example.com/t/a0b1c2d3e4f5g6h7i8j9"
Tanshuku::Url.shorten("https://google.com/", namespace: "c")  #=> "https://example.com/t/abcd0123efgh4567ij89"

# When the same URL and the same namespace is specified, no additional record will be created.
Tanshuku::Url.shorten("https://google.com/", namespace: "a")  #=> "https://example.com/t/ab01cd23ef45gh67ij89"
Tanshuku::Url.shorten("https://google.com/", namespace: "a")  #=> "https://example.com/t/ab01cd23ef45gh67ij89"

More information

cf. Tanshuku::Url.shorten’s API documentation

4. Share the shortened URLs

You can share the shortened URLs, e.g., https://example.com/t/abcdefghij0123456789.

When a user clicks a link with a shortened URL, your Rails app redirects the user to its original URL.

Installation

1. Enable Tanshuku

Add gem "tanshuku" to your application’s Gemfile.

# Gemfile
gem "tanshuku"

2. Generate setup files

Execute a shell command as following:

bin/rails generate tanshuku:install

3. Apply generated migration files

Execute a shell command as following:

bin/rails db:migrate

Q&A

Q. What does “tanshuku” mean?

A. “Tanshuku” is a Japanese word “短縮.” It means “shortening.” And “短縮URL” in Japanese means “shortened URL” in English.

Q. ** (anything you want) isn’t implemented?

A. Does Tanshuku have some missing features? Please create an issue.

How to develop

1. Fork this repository
2. git clone your fork
3. bundle install and rake steep:prepare
4. Update sources
5. rake
6. Fix rake errors if rake fails
7. Create a pull request

How to release

1. Make your repository fresh
2. bump current and confirm the current version
3. bump patch, bump minor, or bump major
4. rake release