Class: BigqueryMigration::ConfigLoader

Inherits:
Object
  • Object
show all
Defined in:
lib/bigquery_migration/config_loader.rb

Defined Under Namespace

Classes: AlreayIncluded

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(config_path, vars = {}) ⇒ ConfigLoader

Returns a new instance of ConfigLoader.



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# File 'lib/bigquery_migration/config_loader.rb', line 12

def initialize(config_path, vars = {})
  @config_path = File.expand_path(config_path)
  @included_files = Set.new
  @namespace = OpenStruct.new(vars)

  unless @namespace.respond_to?(:include_file)
    itself = self
    # ToDo: better way?
    @namespace.define_singleton_method(:include_file) do |path|
      caller_path = caller[0][/^([^:]+):\d+:in `[^']*'$/, 1]
      abs_path = File.expand_path(path, File.dirname(caller_path))
      if File.extname(path) == '.erb'
        itself.load_erb(abs_path)
      else
        File.read(abs_path)
      end
    end
  end
end

Instance Attribute Details

#config_path ⇒ Object (readonly)

Returns the value of attribute config_path.



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# File 'lib/bigquery_migration/config_loader.rb', line 8

def config_path
  @config_path
end

#namespace ⇒ Object (readonly)

Returns the value of attribute namespace.



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# File 'lib/bigquery_migration/config_loader.rb', line 8

def namespace
  @namespace
end

Instance Method Details

#load ⇒ Object 



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# File 'lib/bigquery_migration/config_loader.rb', line 32

def load
  if File.extname(config_path) == '.erb'
    YAML.load(load_erb(config_path))
  else
    YAML.load(File.read(config_path))
  end
end

#load_erb(path = config_path) ⇒ Object 



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# File 'lib/bigquery_migration/config_loader.rb', line 40

def load_erb(path = config_path)
  unless @included_files.add?(path)
    raise AlreayIncluded, "#{path} was included twice"
  end

  raw = File.read(path)
  erb = ERB.new(raw, nil, "-")
  erb.filename = path
  erb.result(namespace.instance_eval { binding })
end