IndexQueryBuilder
This gem provides a DSL on top of ActiveRecord to get collection of models for index pages with filters.
Installation
Add this line to your application's Gemfile:
gem 'index_query_builder'
And then execute:
$ bundle
Or install it yourself as:
$ gem install index_query_builder
Usage
Let's say you have the following schema:
create_table :posts, force: true do |t|
t.text :title
t.integer :view_count
end
create_table :comments, force: true do |t|
t.integer :post_id
t.text :text
end
And the following models
class Post < ActiveRecord::Base
has_many :comments
end
class Comment < ActiveRecord::Base
belongs_to :post
end
And you are building an index page for posts with the following requirements:
- Posts should be ordered by
view_count
. - The user should be able to filter posts by texts in post's comments. For example, if
filters
is { comment_text: 'This post is amazing' }
, then we should return all the posts with a comment containing 'This post is amazing'
. - More filters will be added soon.
Without Index Query Builder, you will probably have to do something like this.
conditions_strings = []
conditions_params = {}
unless filters[:comment_text].blank?
conditions_strings << "comments.text ILIKE :comment_text"
conditions_params[:comment_text] = "%#{filters[:comment_text]}%"
end
conditions = (conditions_params.empty? ? "" : [conditions_strings.join(" AND "), conditions_params])
joins_list = []
joins_list << {:posts => :comment} if filters[:comment_text].present?
posts = Post.where(conditions).joins(joins_list).order("expected_ship_at desc, id desc")
Or, with Index Query Builder, you can just write this.
posts = IndexQueryBuilder.query Post, with: filters do |query|
query.filter_field [:comments, :text], contains: :comment_text
query.order_by "view_count DESC"
end
Operators
Operators will apply where clauses to query only if the filter_name is present in filters hash.
- :equal_to applies field_name = filter_value
- :contains applies substring (ILIKE '%filter_value%')
- :greater_than_or_equal_to applies field_name >= filter_value
- :less_than applies field_name < filter_value
- :present_if applies:
- field_name IS NOT NULL if filter_value
- field_name IS NULL if !filter_value
Find more in the docs
Running tests
It requires PostgreSQL.
$ cp config/database.yml.sample config/database.yml
Update config/database.yml
with your connection information.
$ rake db:test:setup
$ rspec
Contributing
- Fork it ( https://github.com/arturopie/index_query_builder/fork )
- Create your feature branch (
git checkout -b my-new-feature
) - Commit your changes (
git commit -am 'Add some feature'
) - Push to the branch (
git push origin my-new-feature
) - Create a new Pull Request