Class: RedisModel

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/redis_model.rb

Overview

A basic Redis-backed Model implementation. Extend it by specifying your desired attr_accessors Enable timestamps by calling use_timestamps in your implementation Features auto-incremented ids and id namespacing Example:

class Zorro < Fondue::RedisModel
  attr_accessor :sword, :mask
  use_timestamps
end

z = Zorro.new(:sword => 'rapier', :mask => 'lame')
z.persist!
z
=> #<Zorro @id="1", @sword => "rapier", @mask => "lame", @updated_at=2013-03-14 18:11:17 +0100, @created_at=2013-03-14 18:11:17 +0100>

Direct Known Subclasses

Bridge::Game, Bridge::Player

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(params = {}) ⇒ RedisModel

Returns a new instance of RedisModel.



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# File 'lib/redis_model.rb', line 24

def initialize params = {}
  params.map do |k,v| 
    begin
      send(:"#{k}=",JSON.parse(v))
    rescue JSON::ParserError
      send(:"#{k}=",v)
    end
  end
  
  # typecast some standard attributes
  self.id = self.id.to_i if self.id
  if use_timestamps?
    self.created_at = Time.parse(self.created_at) if self.created_at.is_a?(String)
    self.updated_at = Time.parse(self.updated_at) if self.updated_at.is_a?(String)
  end
end

Instance Attribute Details

#id ⇒ Object

the only default attribute



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# File 'lib/redis_model.rb', line 22

def id
  @id
end

Class Method Details

.all ⇒ Object 



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# File 'lib/redis_model.rb', line 108

def all
  $redis.namespace(self)
end

.exists?(id) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/redis_model.rb', line 112

def exists? id
  $redis.exists(namespaced_id(id))
end

.expire_in(time) ⇒ Object 



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# File 'lib/redis_model.rb', line 128

def expire_in time
  @expires_in = time
end

.load(id) ⇒ Object Also known as: find 



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# File 'lib/redis_model.rb', line 116

def load id
  hash = $redis.hgetall(namespaced_id(id))
  hash == {} ? nil : new(hash)
end

.namespaced_id(id) ⇒ Object 



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# File 'lib/redis_model.rb', line 104

def namespaced_id(id)
  "#{self}::#{id}"
end

.use_timestamps ⇒ Object 



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# File 'lib/redis_model.rb', line 122

def use_timestamps
  @use_timestamps = true
  self.send(:attr_accessor, :created_at)
  self.send(:attr_accessor, :updated_at)
end

Instance Method Details

#<=>(other) ⇒ Object 



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# File 'lib/redis_model.rb', line 97

def <=>(other)
  self.to_hash <=> other.to_hash
end

#destroy! ⇒ Object 



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# File 'lib/redis_model.rb', line 63

def destroy!
  $redis.del(namespaced_id)
end

#expires_in ⇒ Object 



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# File 'lib/redis_model.rb', line 83

def expires_in
  self.class.instance_variable_get(:@expires_in)
end

#namespaced_id ⇒ Object 



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# File 'lib/redis_model.rb', line 91

def namespaced_id
  self.class.namespaced_id(self.id)
end

#persist ⇒ Object Also known as: save 



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# File 'lib/redis_model.rb', line 57

def persist
  persist!
  self
end

#persist! ⇒ Object Also known as: save! 



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# File 'lib/redis_model.rb', line 41

def persist!
  is_new = id.nil? or !self.class.exists?(id)
  
  if use_timestamps?
    self.updated_at = Time.now
    self.created_at = Time.now if is_new
  end
  
  self.id = generate_id if is_new
  
  $redis.hmset(namespaced_id, *self.to_array)
  $redis.expire(namespaced_id,expires_in) unless expires_in.nil?
  return true
end

#reload ⇒ Object 



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# File 'lib/redis_model.rb', line 67

def reload
  self.class.load(namespaced_id)
end

#to_array ⇒ Object 



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# File 'lib/redis_model.rb', line 87

def to_array
  to_hash.to_a.flatten
end

#to_hash ⇒ Object 



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# File 'lib/redis_model.rb', line 71

def to_hash
  instance_variables.inject({}) do |h,v|
    value = instance_variable_get(v)
    value = value.is_a?(String) ? value : value.to_json
    h.update v.to_s.gsub('@','') => value
  end
end

#use_timestamps? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/redis_model.rb', line 79

def use_timestamps?
  self.class.instance_variable_get(:@use_timestamps)
end