Module: TaliaUtil::IoHelper

Included in:
TaliaCore::ActiveSourceParts::Rdf::RdfReader, TaliaCore::ActiveSourceParts::Rdf::RdfReader, TaliaCore::ActiveSourceParts::Xml::GenericReader, TaliaCore::ActiveSourceParts::Xml::GenericReader, TaliaCore::DataTypes::FileRecord, ImportJobHelper
Defined in:
lib/talia_util/io_helper.rb

Overview

Collection of IO methods than can be mixed into other classes

Instance Method Summary collapse

Instance Method Details

#base_for(url) ⇒ Object

Will try to figure out the “base”, which is the parent directory or path. If the base is a directory, this will return the directory name, but if it is an URL, this will return an URI object.



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# File 'lib/talia_util/io_helper.rb', line 32

def base_for(url)
  url = file_url(url)
  if(File.exist?(url))
    file = File.expand_path(url)
    File.directory?(file) ? file : File.dirname(file)
  else
    uri = URI.parse(url)
    # Remove everything after the last '/'
    uri.path.gsub!(/\/[^\/]+\Z/, '/')
    uri.fragment = nil
    uri
  end
end

#file_url(uri) ⇒ Object

Get the “file url” for the given uri, stripping a possible file:// from the front



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# File 'lib/talia_util/io_helper.rb', line 80

def file_url(uri)
  uri.gsub(/\Afile:\/\//, '')
end

#open_from_url(url, options = {}) ⇒ Object

Opens the given (web) URL, using URL encoding and necessary substitutions. The user must pass a block which will receive the io object from the url.

The options may contain the http authentication information and such. See the documentation for open-uri for more information. Example for options:

:http_basic_authentication => [, password]

Example:

open_from_url('http://foobar.com/', :http_basic_authentication => ['user', 'secret']) do |io|
  ...
end



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# File 'lib/talia_util/io_helper.rb', line 60

def open_from_url(url, options = {})
  # Encode the URI (the inner decode will save already-encoded URI and should
  # do nothing to non-encoded URIs)
  url = URI.encode(URI.decode(url))
  
  url.gsub!(/\[/, '%5B') # URI class doesn't like unescaped brackets
  url.gsub!(/\]/, '%5D')
  open_args = [ url ]
  open_args << options if(options)

  begin
    open(*open_args) do |io|
      yield(io)
    end
  rescue Exception => e
    raise(IOError, "Error loading #{url} (when file: #{url}, open_args: [#{open_args.join(', ')}]) #{e}")
  end
end

#open_generic(url, options = {}) ⇒ Object

Generic “open” method for files and urls. This won’t choke on file:// URLs and will do some extra escaping on the URL.

Usage:

open_generic('someurl.foo') do |io|
  ...
end

See open_from_url for an explanation of the options



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# File 'lib/talia_util/io_helper.rb', line 18

def open_generic(url, options = {})
  url = file_url(url)
  # Even though open-uri would also open local files, we avoid to mangle
  # the URL in open_from_url
  if(File.exist?(url))
    File.open(url) { |io| yield(io) }
  else
    open_from_url(url, options) { |io| yield(io) }
  end
end