Class: JSONSelect

Inherits:
Object
  • Object
show all
Defined in:
lib/json_select.rb,
lib/json_select/version.rb,
lib/json_select/selector.rb

Defined Under Namespace

Modules: Ast, DepthHelpers, KeyHelpers, PositionHelpers, Selector, SizeHelpers, TypeHelpers Classes: SelectorParser

Constant Summary collapse

ParseError = 
Class.new(RuntimeError)
VERSION = 
"0.1.4"
@@parser_cache = 
{}

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(src, use_parser_cache = true) ⇒ JSONSelect

Returns a new instance of JSONSelect.



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# File 'lib/json_select/selector.rb', line 11

def initialize(src, use_parser_cache=true)
  case src

  when String
    ast = nil

    if use_parser_cache
      ast = @@parser_cache[src]
    end

    if ast
      @ast = ast

    else
      parser = JSONSelect::SelectorParser.new
      tree   = parser.parse(src)
      unless tree
        raise JSONSelect::ParseError, parser.failure_reason
      end

      @ast = tree.to_ast

      if use_parser_cache
        @@parser_cache[src] = ast
      end
    end

  when Array
    @ast = src

  else
    raise ArgumentError, "Expected a string for ast"

  end

  @helpers = Module.new
  @helpers.send(:extend,
    JSONSelect::KeyHelpers,
    JSONSelect::TypeHelpers,
    JSONSelect::SizeHelpers,
    JSONSelect::DepthHelpers,
    JSONSelect::PositionHelpers)

  @helper_methods = {}
  (@helpers.public_methods - Module.public_methods).map do |name|
    @helper_methods[name.to_sym] = @helpers.method(name)
  end
end

Instance Attribute Details

#ast ⇒ Object (readonly)

Returns the value of attribute ast.



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# File 'lib/json_select/selector.rb', line 3

def ast
  @ast
end

Class Method Details

.reset_cache! ⇒ Object 



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# File 'lib/json_select/selector.rb', line 7

def self.reset_cache!
  @@parser_cache.clear
end

Instance Method Details

#inspect ⇒ Object 



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# File 'lib/json_select/selector.rb', line 125

def inspect
  "#<JSONSelect (#{to_s})>"
end

#match(object) ⇒ Object Also known as: =~

Returns the first matching child in object



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# File 'lib/json_select/selector.rb', line 61

def match(object)
  _each(@ast, object, nil, nil, nil, 0) do |object|
    return object
  end

  return nil
end

#matches(object) ⇒ Object

Returns all matching children in object



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# File 'lib/json_select/selector.rb', line 72

def matches(object)
  matches = []

  _each(@ast, object, nil, nil, nil, 0) do |object|
    matches << object
  end

  matches
end

#test(object) ⇒ Object Also known as: ===

Returns true if object has any matching children.



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# File 'lib/json_select/selector.rb', line 83

def test(object)
  _each(@ast, object, nil, nil, nil, 0) do |object|
    return true
  end

  return false
end

#to_s ⇒ Object 



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# File 'lib/json_select/selector.rb', line 93

def to_s
  selectors = @ast
  selectors = (selectors[0] == ',' ? selectors[1..-1] : [selectors])

  selectors.map do |selector|
    selector.map do |part|
      case part

      when :>
        '>'

      when Hash
        tests = (part[:tests].empty? ? ['*'] : part[:tests])

        tests.map do |test|
          case test

          when '*'
            '*'

          when Hash
            @helpers.send("format_#{test[:f]}", test)

          end
        end.join('')

      end

    end.join(' ')
  end.join(', ')
end