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"
endNote: 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 }
endconfig.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: })
    }
endMore 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:install3. Apply generated migration files
Execute a shell command as following:
bin/rails db:migrateQ&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
- Fork this repository
- 
git cloneyour fork
- 
bundle installandrake steep:prepare
- Update sources
- rake
- Fix rakeerrors ifrakefails
- Create a pull request
How to release
- Make your repository fresh
- 
bump currentand confirm the current version
- 
bump patch,bump minor, orbump major
- rake release