Class: FeedTools::DatabaseFeedCache

Inherits:
ActiveRecord::Base
  • Object
show all
Defined in:
lib/feed_tools/database_feed_cache.rb

Overview

The default caching mechanism for the FeedTools module

Class Method Summary collapse

Class Method Details

.config_path ⇒ Object

Returns the path to the database.yml config file that FeedTools loaded.



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# File 'lib/feed_tools/database_feed_cache.rb', line 92

def DatabaseFeedCache.config_path
  if !defined?(@config_path) || @config_path.blank?
    @config_path = nil
  end
  return @config_path
end

.connected? ⇒ Boolean

Returns true if a connection to the database has been established and the required table structure is in place.

Returns:

  • (Boolean) 


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# File 'lib/feed_tools/database_feed_cache.rb', line 101

def DatabaseFeedCache.connected?
  begin
    ActiveRecord::Base.connection
    return false if ActiveRecord::Base.configurations.nil?
    return false unless DatabaseFeedCache.table_exists?
  rescue => error
    return false
  end
  return true
end

.initialize_cache ⇒ Object

If ActiveRecord is not already connected, attempts to find a configuration file and use it to open a connection for ActiveRecord. This method is probably unnecessary for anything but testing and debugging purposes. In a Rails environment, the connection will already have been established and this method will simply do nothing.

This method should not raise any exceptions because it’s designed to be run only when the module is first loaded. If it fails, the user should get an exception when they try to perform some action that makes use of the caching functionality, and not until.



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# File 'lib/feed_tools/database_feed_cache.rb', line 48

def DatabaseFeedCache.initialize_cache
  # Establish a connection if we don't already have one
  begin
    ActiveRecord::Base.default_timezone = :utc
    ActiveRecord::Base.connection
  rescue
  end
  if !ActiveRecord::Base.connected?
    begin
      possible_config_files = [
        "./config/database.yml",
        "./database.yml",
        "../config/database.yml",
        "../database.yml",
        "../../config/database.yml",
        "../../database.yml",
        "../../../config/database.yml",
        "../../../database.yml"
      ]
      database_config_file = nil
      for file in possible_config_files
        if File.exists?(File.expand_path(file))
          database_config_file = file
          @config_path = database_config_file
          break
        end
      end
      database_config_hash = File.open(database_config_file) do |file|
        config_hash = YAML::load(file)
        unless config_hash[FEED_TOOLS_ENV].nil?
          config_hash = config_hash[FEED_TOOLS_ENV]
        end
        config_hash
      end
      ActiveRecord::Base.configurations = database_config_hash
      ActiveRecord::Base.establish_connection(database_config_hash)
      ActiveRecord::Base.connection
    rescue
    end
  end
  return nil
end

.set_up_correctly? ⇒ Boolean

False if there is an error of any kind

Returns:

  • (Boolean) 


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# File 'lib/feed_tools/database_feed_cache.rb', line 113

def DatabaseFeedCache.set_up_correctly?
  begin
    ActiveRecord::Base.connection
    if !ActiveRecord::Base.configurations.nil? &&
      !DatabaseFeedCache.table_exists?
      return false
    end
  rescue Exception
    return false
  end
  return true
end

.table_exists? ⇒ Boolean

True if the appropriate database table already exists

Returns:

  • (Boolean) 


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# File 'lib/feed_tools/database_feed_cache.rb', line 127

def DatabaseFeedCache.table_exists?
  begin
    ActiveRecord::Base.connection.select_one("select id, href, title, " +
      "link, feed_data, feed_data_type, http_headers, last_retrieved " +
      "from #{self.table_name()}")
  rescue ActiveRecord::StatementInvalid
    return false
  rescue
    return false
  end
  return true
end