# Cursed [![CircleCI](https://circleci.com/gh/influitive/cursed.svg?style=svg)](https://circleci.com/gh/influitive/cursed) Cursed is a gem that implements the cursoring pattern in Postgres with the ActiveRecord and Sequel gems. The cursoring pattern is an alternative to traditional pagination which is superior in that it is stable for collections that are constantly changing. Instead of providing a parameter `page` we instead provide any of three parameters `before`, `after` and `limit` (you may customize these as you wish). By choosing to 'paginate' by providing the maximum ID you know about you can be assured that the same record will not appear twice if records behind it have changed it's position. ## Installation Add this line to your application's Gemfile: ```ruby gem 'cursed' ``` And then execute: $ bundle Or install it yourself as: $ gem install cursed ## Usage In your controller code call your collection in this manner. ```ruby Cursed::Collection.new( relation: MyModel.unscoped, cursor: Cursed::Cursor.new( after: params[:after], before: params[:before], limit: params[:limit], maximum: 20 ) ) ``` The `Collection` is enumerable so you can use it as you would us any array ```erb <% @collection.each do |record| %> <%= record.name %> <% end %> ``` To generate your next link and previous link merge in the values of `#next_page_params` and `#prev_page_params` into your URL generator. `#next_page?` and `#prev_page?` can be used to determine if there are next or previous pages of records currently. ```erb <% if collection.prev_page? %> <%= link_to 'Previous Page', widgets_path(collection.prev_page_params) %> <% end %> <% if collection.next_page? %> <%= link_to 'Next Page', widgets_path(collection.next_page_params) %> <% end %> ``` ## Development After checking out the repo, run `bin/setup` to install dependencies. You can also run `bin/console` for an interactive prompt that will allow you to experiment. To install this gem onto your local machine, run `bundle exec rake install`. To release a new version, update the version number in `version.rb`, and then run `bundle exec rake release`, which will create a git tag for the version, push git commits and tags, and push the `.gem` file to [rubygems.org](https://rubygems.org). ## Contributing Bug reports and pull requests are welcome on GitHub at https://github.com/influitive/cursed. ## License This gem is licensed under the MIT license.