has_messages

has_messages demonstrates a reference implementation for sending messages between users.

Resources

API

• api.pluginaweek.org/has_messages

Bugs

• pluginaweek.lighthouseapp.com/projects/13274-has_messages

Development

• github.com/pluginaweek/has_messages

Source

• git://github.com/pluginaweek/has_messages.git

Description

Messaging between users is fairly common in web applications, especially those that support social networking. Messaging doesn’t necessarily need to be between users, but can also act as a way for the web application to send notices and other notifications to users.

Designing and building a framework that supports this can be complex and takes away from the business focus. This plugin can help ease that process by demonstrating a complete implementation of these features.

Usage

Adding message support

  class User < ActiveRecord::Base
    has_messages
  end

This will build the following associations:

• messages
• unsent_messages
• sent_messages
• received_messages

If you have more specified needs, you can create the same associations manually that has_messages builds. See PluginAWeek::HasMessages::MacroMethods#has_messages for more information about the asssociations that are generated from this macro.

Creating new messages

  message = user.messages.build
  message.to user1, user2
  message.subject = 'Hey!'
  message.body = 'Does anyone want to go out tonight?'
  message.deliver

Replying to messages

  reply = message.reply_to_all
  reply.body = "I'd love to go out!"
  reply.deliver

Forwarding messages

  forward = message.forward
  forward.body = 'Interested?'
  forward.deliver

Processing messages asynchronously

In addition to delivering messages immediately, you can also queue messages so that an external application processes and delivers them. This is especially useful for messages that need to be sent outside of the confines of the application.

To queue messages for external processing, you can use the queue event, rather than deliver. This will indicate to any external processes that the message is ready to be sent.

To process queued emails, you need an external cron job that checks and sends them like so:

  Message.with_state('queued').each do |message|
    message.deliver
  end

Testing

Before you can run any tests, the following gem must be installed:

• plugin_test_helper

To run against a specific version of Rails:

  rake test RAILS_FRAMEWORK_ROOT=/path/to/rails

Dependencies

• Rails 2.1 or later
• state_machine
• plugins_plus (optional if app files are copied to your project tree)