Class: Howdy::Dictionary::Base

Inherits:
Object
  • Object
show all
Defined in:
lib/howdy/base.rb

Overview

Base class for all dictionaries. Inherit from it if you want to implement your own dictionary.

Example:

  class AwesomeDictionary < Howdy::Dictionary::Base

    url 'http://awesome.example.com?word=#{user_query}'
    label 'example.com'
    description 'Most awesome dictionary you've ever seen'

    def parse
      document.css('table.results tr td.word') do |cell|
        result << cell.content
      end
    end
  end

Direct Known Subclasses

DictPl, DictionaryCom, LingPl, UrbanDictionaryCom

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(user_query) ⇒ Base

:nodoc



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# File 'lib/howdy/base.rb', line 72

def initialize(user_query) # :nodoc
  @user_query = user_query.squeeze(' ').strip
end

Instance Attribute Details

#user_query ⇒ Object (readonly)

Returns the value of attribute user_query.



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# File 'lib/howdy/base.rb', line 66

def user_query
  @user_query
end

Class Method Details

.description(dictionary_description) ⇒ Object

Sets a description of the dictionary. Description is used when listing available dictionaries.



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# File 'lib/howdy/base.rb', line 124

def self.description(dictionary_description)
  @description = dictionary_description
end

.dict_description ⇒ Object

Returns description of the dictionary.



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# File 'lib/howdy/base.rb', line 134

def self.dict_description
  @description ||= ""
end

.dict_label ⇒ Object

Returns label of the dictionary.



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# File 'lib/howdy/base.rb', line 129

def self.dict_label
  @name ||= self.label.underscore
end

.dict_url ⇒ Object

Returns URL of the dictionary



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# File 'lib/howdy/base.rb', line 112

def self.dict_url
  @url
end

.doc_encoding ⇒ Object

Returns an encoding of HTTP response. UTF-8 by default.



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# File 'lib/howdy/base.rb', line 144

def self.doc_encoding
  @encoding ||= 'UTF-8'
end

.encoding(enc) ⇒ Object

Sets an encoding of content returned by HTTP response.



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# File 'lib/howdy/base.rb', line 139

def self.encoding(enc)
  @encoding = enc.to_s
end

.inherited(base) ⇒ Object

:nodoc



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# File 'lib/howdy/base.rb', line 68

def self.inherited(base) # :nodoc
  Howdy::Dictionary.available << base
end

.label(human_name) ⇒ Object

Sets a label of the dictionary. Label is used when listing available dictionaries



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# File 'lib/howdy/base.rb', line 118

def self.label(human_name)
  @name = human_name.to_s
end

.url(dictionary_url) ⇒ Object

Sets URL to query the web dictionary. You must pass protocol as well:

http://dictionary.com is correct
dictionary.com is incorrect

URL is interpolated:

'http://dictionary.com/browse/#{user_query}'

user_query is a string given by the user

You may provide own interpolations easily:

Example:
class Dictionary < Howdy::Dictionary::Base
  url 'http://awesome.example.com?word=#{user_query}&language=#{lang}'
  label 'example.com'
  description 'Interpolations example'

  def lang
    File.read('/etc/howdy/language.conf')
  end

  def parse
     # implement parsing
  end

end

In that example #{lang} in url will be replaced with content of
/etc/howdy/language.conf

Indicate the url must be given using SINGLE QUOTES.



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# File 'lib/howdy/base.rb', line 107

def self.url(dictionary_url)
  @url = dictionary_url
end

Instance Method Details

#document ⇒ Object

Returns content of HTTP response wrapped in Nokogiri::HTML backend.



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# File 'lib/howdy/base.rb', line 167

def document
  # FIXME: deal more sophistically with exception
  begin
    @document ||= Nokogiri::HTML(open(URI.escape(interpolated_url)), nil, self.class.doc_encoding)
  rescue
    UI.error "Nothing found"
    exit 0
  end
end

#parse ⇒ Object

Method which transformates raw content received in HTTP response to human-friendly form. Usually you’ll use document which exposes the raw content wrapped by Nokogiri parser. Read to nokogiri documentation for details.

Each human readable word goes to result array.

Example:
  def parse
    document.css('table.content tr td.word').each do |row|
      result << row.content
    end
  end

Raises:



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# File 'lib/howdy/base.rb', line 162

def parse
  raise Howdy::HowdyError, "Implement parse in your Dictionary::Base subclass"
end

#print ⇒ Object

Prints the contents of result array. You may ovveride it in subclass.



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# File 'lib/howdy/base.rb', line 185

def print
  if result.empty?
    puts "Nothing found"
  else
    result.each do |item|
      puts item.to_s
    end
  end
end

#result ⇒ Object

Array which stores the answers for the user query. Used in parse method.

Example:
result << 'Polyglot - a person who speaks, writes, or reads a number of languages'



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# File 'lib/howdy/base.rb', line 180

def result
  @result ||= []
end