README.md
# Bustle [![endorse](http://api.coderwall.com/fredwu/endorsecount.png)](http://coderwall.com/fredwu) [![Build Status](https://secure.travis-ci.org/fredwu/bustle.png?branch=master)](http://travis-ci.org/fredwu/bustle) [![Dependency Status](https://gemnasium.com/fredwu/bustle.png)](https://gemnasium.com/fredwu/bustle) [![Code Climate](https://codeclimate.com/badge.png)](https://codeclimate.com/github/fredwu/bustle)
Activities recording and retrieving using a simple Pub/Sub-like interface.
The typical use cases are:
- Timeline (e.g. tracking activities such as posting and commenting for users)
- Logging
The advantages of Bustle are:
- It is lightweight and simple to use
- It is largely self-contained and separated from you core app logic
- It works nicely with ActiveRecord out of box
- It is ORM-agnostic therefore can be extended to use with other databases
- It has full unit test coverage
Bustle is built for simplicity and extensibility. If you are after high performance pub/sub then this gem is not for you.
## Installation
Add this line to your application's Gemfile:
```ruby
gem 'bustle'
```
## Usage
### Configuration
First of all, you will need to configure Bustle. If you are using Rails, you can put the following code in an initializer (e.g. `config/initializers/bustle.rb`).
```ruby
Bustle.config do |c|
# Specify a storage strategy for storing activities
# Bustle ships with an ActiveRecord storage strategy
c.storage = Bustle::Storage::ActiveRecord
end
```
For ActiveRecord, you will need the following migration file:
```ruby
class CreateBustleTables < ActiveRecord::Migration
def change
create_table :bustle_activities do |t|
t.string :resource_class
t.integer :resource_id
t.string :action, :default => ''
t.text :data, :default => ''
t.integer :publisher_id, :null => false
t.timestamps
end
create_table :bustle_publishers do |t|
t.string :resource_class, :null => false
t.integer :resource_id, :null => false
t.timestamps
end
create_table :bustle_subscribers do |t|
t.string :resource_class, :null => false
t.integer :resource_id, :null => false
t.timestamps
end
create_table :bustle_subscriptions do |t|
t.integer :publisher_id, :null => false
t.integer :subscriber_id, :null => false
t.timestamps
end
add_index :bustle_activities, :publisher_id
add_index :bustle_publishers, [:resource_class, :resource_id], :unique => true
add_index :bustle_subscribers, [:resource_class, :resource_id], :unique => true
add_index :bustle_subscriptions, :publisher_id
add_index :bustle_subscriptions, :subscriber_id
add_index :bustle_subscriptions, [:publisher_id, :subscriber_id], :unique => true
end
end
```
### Flow
Upon subscribing:
1. Subscriber registers itself if not already registered
2. Publisher registers itself if not already registered
3. A Subscription is created for Subscriber and Publisher
When activities occur:
1. Publisher registers itself if not already registered
2. Publisher publishes activity
### API
#### Register a Subscriber
```ruby
# returns a subscriber instance upon duplicated entry
Bustle::Subscribers.add subscriber
# raises error upon duplicated entry
Bustle::Subscribers.add! subscriber
# example
user = User.find(1)
Bustle::Subscribers.add user
```
#### Register a Publisher
```ruby
# returns a publisher instance upon duplicated entry
Bustle::Publishers.add publisher
# raises error upon duplicated entry
Bustle::Publishers.add! publisher
# example
post = Post.find(1)
Bustle::Publishers.add post
```
#### Create a Subscription
```ruby
# returns a subscription instance upon duplicated entry
Bustle::Subscriptions.add bustle_publisher, bustle_subscriber
# raises error upon duplicated entry
Bustle::Subscriptions.add! bustle_publisher, bustle_subscriber
# example
publisher = Bustle::Publishers.get(Post.first)
subscriber = Bustle::Subscribers.get(User.first)
Bustle::Subscriptions.add publisher, subscriber
```
#### Find a Subscriber/Publisher/Subscription
```ruby
Bustle::Subscribers.get subscriber
Bustle::Publishers.get publisher
Bustle::Subscriptions.get bustle_publisher, bustle_subscriber # => Bustle::Subscription
Bustle::Subscriptions.by bustle_publisher # => an array of Bustle::Subscription by the publisher
Bustle::Subscriptions.for bustle_subscriber # => an array of Bustle::Subscription for the subscriber
```
#### Remove a Subscriber/Publisher/Subscription
```ruby
Bustle::Subscribers.remove subscriber
Bustle::Publishers.remove publisher
Bustle::Subscriptions.remove bustle_publisher, bustle_subscriber
# or use `remove!` to raise an exception if the resource cannot be found
```
Or:
```ruby
Bustle::Subscribers.get(subscriber).destroy
Bustle::Publishers.get(publisher).destroy
Bustle::Subscriptions.get(bustle_publisher, bustle_subscriber).destroy
```
#### Find Referenced Resources
These are helpful for finding referenced resources.
```ruby
Bustle::Activity#publisher_resource
Bustle::Activity#target_resource
Bustle::Publisher#target_resource
Bustle::Subscriber#target_resource
Bustle::Subscription#publisher_resource
Bustle::Subscription#subscriber_resource
```
#### Publish an Activity
```ruby
Bustle::Activities.add bustle_publisher, {
:resource => some_resource,
:action => some_string,
:data => some_text
}
# or
Bustle::Publisher.publish({
:resource => some_resource,
:action => some_string,
:data => some_text
})
# example
post = Post.find(1)
comment = post.comments.add(:content => "I'm a comment")
Bustle::Publishers.add post
publisher = Bustle::Publishers.get post
publisher.publish({
:resource => comment,
:action => 'new',
:data => 'useful for putting serialized data or JSON here'
})
```
#### Activities
##### Retrieve Activities for a Subscriber
```ruby
Bustle::Activities.for bustle_subscriber
# or
Bustle::Subscriber.activities
# example
subscriber = Bustle::Subscribers.get(User.first)
subscriber.activities
```
##### Retrieve Activities by a Publisher
```ruby
Bustle::Activities.by bustle_publisher
# or
Bustle::Publisher.activities
# example
publisher = Bustle::Publishers.get(Post.first)
publisher.activities
```
#### Filtering (for Activities and Subscriptions)
```ruby
Bustle::Activities.filter :key => :value
Bustle::Subscriptions.filter :key => :value
# or
Bustle::Subscriber.activities :key => :value
# example
subscriber = Bustle::Subscribers.get(User.first)
subscriber.activities :action => 'new'
```
## License
This gem is released under the [MIT License](http://www.opensource.org/licenses/mit-license.php).
## Author
[Fred Wu](https://github.com/fredwu), originally built for [500 Startups](http://500.co).
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