Module: Yarss::Attribute

Defined in:
lib/yarss/attribute.rb

Overview

A bunch of helpers to extract a String value out of a Hash, Array, etc.

Class Method Summary collapse

Class Method Details

.author_value(value) ⇒ String

Extract a String value from a given author attribute.

Examples:

Yarss::Attribute.author_value('Foo') # => 'Foo'
Yarss::Attribute.author_value('name' => 'Foo') # => 'Foo'

Parameters:

  • value (String, Hash) —

    An attribute.

Returns:

  • (String)

Raises:



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# File 'lib/yarss/attribute.rb', line 44

def self.author_value(value)
  value ||= ''

  case value
  when Hash
    value(value.fetch('name'))
  when String
    value.strip
  else
    raise ParseError, "Unknown #{value.class} attribute: #{value.inspect}"
  end
rescue KeyError => e
  raise ParseError, e
end

.link_value(value) ⇒ String

Extract a String value from a given link attribute.

Examples:

Yarss::Attribute.link_value('Foo') # => 'Foo'
Yarss::Attribute.link_value('href' => 'Foo') # => 'Foo'
Yarss::Attribute.link_value([{ 'rel' => 'self', 'href' => 'Foo' }])
  # => 'Foo'
Yarss::Attribute.link_value([{ 'rel' => 'alternate', 'href' => 'Foo' }])
  # => 'Foo'

Parameters:

  • value (String, Hash, Array) —

    A link attribute.

Returns:

  • (String)

Raises:

  • (ParseError) —

    If type of value is not known or no link is found.



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# File 'lib/yarss/attribute.rb', line 74

def self.link_value(value)
  value ||= ''

  case value
  when Hash
    link_value(value.fetch('href'))
  when Array
    item = value.find { |l| l.is_a?(String) } ||
           value.find { |l| l['rel'] && l['rel'] == 'self' } ||
           value.find { |l| l['rel'] && l['rel'] == 'alternate' }
    raise KeyError unless item
    link_value(item)
  when String
    value.strip
  else
    raise ParseError, "Unknown #{value.class} attribute: #{value.inspect}"
  end
rescue KeyError => e
  raise ParseError, e
end

.value(value) ⇒ String

Extract a String value from a given attribute.

Examples:

Yarss::Attribute.value('Foo') # => 'Foo'
Yarss::Attribute.value('__content__' => 'Foo') # => 'Foo'

Parameters:

  • value (String, Hash) —

    An attribute.

Returns:

  • (String)

Raises:



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# File 'lib/yarss/attribute.rb', line 18

def self.value(value)
  value ||= ''

  case value
  when Hash
    value(value.fetch('__content__'))
  when String
    value.strip
  else
    raise ParseError, "Unknown #{value.class} attribute: #{value.inspect}"
  end
rescue KeyError => e
  raise ParseError, e
end