Module: IMW::Resources

Includes:
Formats, Schemes
Defined in:
lib/imw/resources.rb,
lib/imw/resources/local.rb,
lib/imw/resources/remote.rb,
lib/imw/resources/archive.rb,
lib/imw/resources/formats.rb,
lib/imw/resources/schemes.rb,
lib/imw/resources/schemes/s3.rb,
lib/imw/resources/compressible.rb,
lib/imw/resources/formats/json.rb,
lib/imw/resources/formats/sgml.rb,
lib/imw/resources/formats/yaml.rb,
lib/imw/resources/schemes/hdfs.rb,
lib/imw/resources/schemes/http.rb,
lib/imw/resources/compressed_file.rb,
lib/imw/resources/formats/delimited.rb,
lib/imw/resources/archives_and_compressed.rb,
lib/imw/resources/archives_and_compressed/gz.rb,
lib/imw/resources/archives_and_compressed/bz2.rb,
lib/imw/resources/archives_and_compressed/rar.rb,
lib/imw/resources/archives_and_compressed/tar.rb,
lib/imw/resources/archives_and_compressed/zip.rb,
lib/imw/resources/archives_and_compressed/targz.rb,
lib/imw/resources/archives_and_compressed/tarbz2.rb

Overview

IMW::Resources is a namespace in which all the modules which define different kinds of behavior for IMW::Resource objects are defined.

When an IMW::Resource is instantiated it eventually calls IMW::Resources#extend_resource! which will iterate through the handlers in IMW::Resources#handlers, extending the resource with modules whose handler conditions are satisfied.

A handler is just an Array with two elements. The first should be a module or a string identifying a module.

If the second element is a Regexp, the corresponding module will be used if the regexp matches the resource’s URI (as a string)

If the second element is a Proc, it will be called with the resource as its only argument and if it returns true then the module will be used.

You can define your own handlers by appending them to IMW::Resources::USER_DEFINED_HANDLERS in your .imwrc file.

Defined Under Namespace

Modules: Archive, Archives, CompressedFile, CompressedFiles, Compressible, Formats, LocalDirectory, LocalFile, LocalObj, RemoteDirectory, RemoteFile, RemoteObj, Schemes

Constant Summary collapse

BASIC_HANDLERS =

Basic handlers to determine whether the resource is local, remote, or a string.

[
 ["LocalObj",  Proc.new { |resource| resource.scheme == 'file' || resource.scheme.blank?   } ],
 ["RemoteObj", Proc.new { |resource| resource.scheme != 'file' && resource.scheme.present? } ],
 ["StringObj", Proc.new { |resource| resource.is_stringio?                                 } ]
]
USER_DEFINED_HANDLERS =

Define this constant in your configuration file to add your own handlers.

[]
ARCHIVE_AND_COMPRESSED_HANDLERS =

Handlers which augment the resource with methods for archiving, extracting, compressing, decompressing…

[

 # try compressible first -- compressed files below will override it
 ["Compressible",         Proc.new { |r| r.is_local? } ],

 # order is important! -- tar.bz2 must come before .bz2, &c.
 ["Archives::Tarbz2",     Proc.new { |r| r.is_local? && r.path =~ /\.tar\.bz2$/                                              } ],
 ["Archives::Tarbz2",     Proc.new { |r| r.is_local? && r.path =~ /\.tbz2$/                                                  } ],
 ["CompressedFiles::Bz2", Proc.new { |r| r.is_local? && r.path =~ /\.bz2$/ && r.path !~ /\.tar\.bz2$/ && r.path !~ /\.tbz2$/ } ],
 ["Archives::Targz",      Proc.new { |r| r.is_local? && r.path =~ /\.tar\.gz$/                                               } ],
 ["Archives::Targz",      Proc.new { |r| r.is_local? && r.path =~ /\.tgz$/                                                   } ],
 ["CompressedFiles::Gz",  Proc.new { |r| r.is_local? && r.path =~ /\.gz$/  && r.path !~ /\.tar\.gz$/  && r.path !~ /\.tgz$/  } ],
 ["Archives::Tar",        Proc.new { |r| r.is_local? && r.path =~ /\.tar$/                                                   } ],
 ["Archives::Rar",        Proc.new { |r| r.is_local? && r.path =~ /\.rar$/                                                   } ],
 ["Archives::Zip",        Proc.new { |r| r.is_local? && r.path =~ /\.zip$/                                                   } ]

]

Constants included from Schemes

Schemes::SCHEME_HANDLERS

Constants included from Formats

Formats::FORMAT_HANDLERS

Class Method Summary collapse

Class Method Details

.extend_resource!(resource) ⇒ IMW::Resource

Iterate through IMW::Resources#handlers and extend the given resource with modules whose handler conditions match the resource.

Parameters:

Returns:



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# File 'lib/imw/resources.rb', line 42

def self.extend_resource! resource
  handlers.each do |mod_name, handler|
    case handler
    when Regexp    then extend_resource_with_mod_or_string!(resource, mod_name) if handler =~ resource.uri.to_s
    when Proc      then extend_resource_with_mod_or_string!(resource, mod_name) if handler.call(resource)
    when TrueClass then extend_resource_with_mod_or_string!(resource, mod_name)
    else
      raise IMW::TypeError("A handler must be Regexp, Proc, or true")
    end
  end
  resource
end

.handlers ⇒ Array

A list of handlers to try. Define your own handlers in IMW::Resources::USER_DEFINED_HANDLERS.

Returns:



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# File 'lib/imw/resources.rb', line 75

def self.handlers
  # order here is important
  BASIC_HANDLERS + SCHEME_HANDLERS + ARCHIVE_AND_COMPRESSED_HANDLERS + FORMAT_HANDLERS + USER_DEFINED_HANDLERS
end