Class: RJR::Arguments

Inherits:
Object show all
Extended by:
Forwardable
Includes:
Enumerable
Defined in:
lib/rjr/util/args.rb

Overview

Encapsulates a list of JSON-RPC method arguments as sent from the client to the server, in addition to providing various helper / utility methods.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(args = {}) ⇒ Arguments

Returns a new instance of Arguments.



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# File 'lib/rjr/util/args.rb', line 21

def initialize(args={})
  @args = args[:args] || []
end

Instance Attribute Details

#args ⇒ Object

Returns the value of attribute args.



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# File 'lib/rjr/util/args.rb', line 17

def args
  @args
end

Instance Method Details

#extract(map) ⇒ Object

Extract groups of values from argument list

Groups are generated by comparing arguments to keys in the specified map and on matches extracting the # of following arguments specified by the map values

Note arguments / keys are converted to strings before comparison

Examples:

args = Arguments.new :args => ['with_id', 123, 'custom', 'another']
args.extract :with_id => 1, :custom => 0
  # => [['with_id', 123], ['custom']]


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# File 'lib/rjr/util/args.rb', line 93

def extract(map)
  # clone map hash, swap keys for string
  map = Hash[map]
  map.keys.each { |k|
    map[k.to_s] = map[k]
    map.delete(k) unless k.is_a?(String)
  }

  groups = []
  i = 0
  while(i < length) do
    val = self[i]
    i += 1
    next unless !!map.has_key?(val)

    num = map[val]
    group = [val]
    0.upto(num-1) do |j|
      group << self[i]
      i += 1
    end
    groups << group
  end

  groups
end

#specifier_for(tag) ⇒ Object

Return specifier corresponding given tag. The specifier is defined as the value appearing in the argument list immediately after the tag

Examples:

args = Argument.new :args => ['with_id', 123]
args.specifier_for('with_id') #=> 123
args.specifier_for('other')   #=> nil


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# File 'lib/rjr/util/args.rb', line 140

def specifier_for(tag)
  return nil unless specifies?(tag)
  self[index(tag) + 1]
end

#specifies?(tag) ⇒ Boolean

Return boolean if tag appears in argument list. Simple wrapper around includes setting up the scope of argument ‘specifiers’

Examples:

args = Arguments.new :args => ['foobar']
args.specifies?('foobar') #=> true
args.specifies?('barfoo') #=> false

Returns:

  • (Boolean) 


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# File 'lib/rjr/util/args.rb', line 128

def specifies?(tag)
  include?(tag)
end

#validate!(*acceptable) ⇒ Object

Validate arguments against acceptable values.

Raises error if value is found which is not on list of acceptable values.

If acceptable values are hash’s, keys are compared and on matches the values are used as the # of following arguments to skip in the validator

Note args / acceptable params are converted to strings before comparison

Examples:

args = Arguments.new :args => ['custom', 'another']
args.validate! 'custom', 'another'  #=> nil
args.validate! 'something'          #=> ArgumentError

args = Arguments.new :args => ['with_id', 123, 'another']
args.validate! :with_id => 1, :another => 0 #=> nil
args.validate! :with_id => 1                #=> ArgumentError


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# File 'lib/rjr/util/args.rb', line 45

def validate!(*acceptable)
  i = 0
  if acceptable.first.is_a?(Hash)
    # clone acceptable hash, swap keys for string
    acceptable = Hash[acceptable.first]
    acceptable.keys.each { |k|
      acceptable[k.to_s] = acceptable[k]
      acceptable.delete(k) unless k.is_a?(String)
    }

    # compare acceptable against arguments, raising error if issue found
    while(i < length) do
      val = self[i]
      passed = acceptable.has_key?(val)
      raise ArgumentError, "#{val} not an acceptable arg" unless passed
      skip = acceptable[val]
      i += (skip + 1)
    end

  else
    # clone acceptable array, swap values for string
    acceptable = Array.new(acceptable).map { |a| a.to_s }

    # compare acceptable against arguments, raising error if issue found
    while(i < length) do
      val = self[i].to_s
      passed = acceptable.include?(val)
      raise ArgumentError, "#{val} not an acceptable arg" unless passed
      i += 1
    end
  end

  nil
end