Class: JSON::Validator

Inherits:
Object
  • Object
show all
Defined in:
lib/json-schema/validator.rb

Constant Summary collapse

@@schemas =
{}
@@cache_schemas =
false
@@default_opts =
{
  :list => false,
  :version => nil,
  :validate_schema => false,
  :record_errors => false,
  :errors_as_objects => false,
  :insert_defaults => false
}
@@validators =
{}
@@default_validator =
nil
@@available_json_backends =
[]
@@json_backend =
'yajl'
@@serializer =
lambda{|o| Marshal.dump(o) }
@@mutex =
Mutex.new

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(schema_data, data, opts = {}) ⇒ Validator

Returns a new instance of Validator.



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# File 'lib/json-schema/validator.rb', line 144

def initialize(schema_data, data, opts={})
  @options = @@default_opts.clone.merge(opts)
  @errors = []

  # I'm not a fan of this, but it's quick and dirty to get it working for now
  version_string = "draft-04"
  if @options[:version]
    version_string = @options[:version] = self.class.version_string_for(@options[:version])
    u = URI.parse("http://json-schema.org/#{@options[:version]}/schema#")
    validator = JSON::Validator.validators["#{u.scheme}://#{u.host}#{u.path}"]
    @options[:version] = validator
  end

  @validation_options = @options[:record_errors] ? {:record_errors => true} : {}
  @validation_options[:insert_defaults] = true if @options[:insert_defaults]

  @@mutex.synchronize { @base_schema = initialize_schema(schema_data) }
  @data = initialize_data(data)
  @@mutex.synchronize { build_schemas(@base_schema) }

  # validate the schema, if requested
  if @options[:validate_schema]
    begin
      if @base_schema.schema["$schema"]
        version_string = @options[:version] = self.class.version_string_for(@base_schema.schema["$schema"])
      end
      meta_validator = JSON::Validator.new(self.class.metaschema_for(version_string), @base_schema.schema)
      meta_validator.validate
    rescue JSON::Schema::ValidationError, JSON::Schema::SchemaError
      raise $!
    end
  end

  # If the :fragment option is set, try and validate against the fragment
  if opts[:fragment]
    @base_schema = schema_from_fragment(@base_schema, opts[:fragment])
  end
end

Class Method Details

.add_schema(schema) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 424

def add_schema(schema)
  @@schemas[schema.uri.to_s] = schema if @@schemas[schema.uri.to_s].nil?
end

.cache_schemas=(val) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 428

def cache_schemas=(val)
  @@cache_schemas = val == true ? true : false
end

.clear_cacheObject



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# File 'lib/json-schema/validator.rb', line 416

def clear_cache
  @@schemas = {} if @@cache_schemas == false
end

.default_validatorObject



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# File 'lib/json-schema/validator.rb', line 436

def default_validator
  @@default_validator
end

.fully_validate(schema, data, opts = {}) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 396

def fully_validate(schema, data, opts={})
  opts[:record_errors] = true
  validator = JSON::Validator.new(schema, data, opts)
  validator.validate
end

.fully_validate_json(schema, data, opts = {}) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 408

def fully_validate_json(schema, data, opts={})
  fully_validate(schema, data, opts.merge(:json => true))
end

.fully_validate_schema(schema, opts = {}) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 402

def fully_validate_schema(schema, opts={})
  data = schema
  schema = metaschema_for(version_string_for(opts[:version]))
  fully_validate(schema, data, opts)
end

.fully_validate_uri(schema, data, opts = {}) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 412

def fully_validate_uri(schema, data, opts={})
  fully_validate(schema, data, opts.merge(:uri => true))
end

.json_backendObject



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# File 'lib/json-schema/validator.rb', line 448

def json_backend
  if defined?(MultiJson)
    MultiJson.respond_to?(:adapter) ? MultiJson.adapter : MultiJson.engine
  else
    @@json_backend
  end
end

.json_backend=(backend) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 456

def json_backend=(backend)
  if defined?(MultiJson)
    backend = backend == 'json' ? 'json_gem' : backend
    MultiJson.respond_to?(:use) ? MultiJson.use(backend) : MultiJson.engine = backend
  else
    backend = backend.to_s
    if @@available_json_backends.include?(backend)
      @@json_backend = backend
    else
      raise JSON::Schema::JsonParseError.new("The JSON backend '#{backend}' could not be found.")
    end
  end
end

.metaschema_for(version_string) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 140

def self.metaschema_for(version_string)
  File.join(Pathname.new(File.dirname(__FILE__)).parent.parent, "resources", "#{version_string}.json").to_s
end

.parse(s) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 470

def parse(s)
  if defined?(MultiJson)
    MultiJson.respond_to?(:adapter) ? MultiJson.load(s) : MultiJson.decode(s)
  else
    case @@json_backend.to_s
    when 'json'
      JSON.parse(s)
    when 'yajl'
      json = StringIO.new(s)
      parser = Yajl::Parser.new
      parser.parse(json)
    else
      raise JSON::Schema::JsonParseError.new("No supported JSON parsers found. The following parsers are suported:\n * yajl-ruby\n * json")
    end
  end
end

.register_default_validator(v) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 444

def register_default_validator(v)
  @@default_validator = v
end

.register_validator(v) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 440

def register_validator(v)
  @@validators[v.to_s] = v
end

.schemasObject



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# File 'lib/json-schema/validator.rb', line 420

def schemas
  @@schemas
end

.validate(schema, data, opts = {}) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 363

def validate(schema, data,opts={})
  begin
    validator = JSON::Validator.new(schema, data, opts)
    validator.validate
    return true
  rescue JSON::Schema::ValidationError, JSON::Schema::SchemaError
    return false
  end
end

.validate!(schema, data, opts = {}) ⇒ Object Also known as: validate2



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# File 'lib/json-schema/validator.rb', line 381

def validate!(schema, data,opts={})
  validator = JSON::Validator.new(schema, data, opts)
  validator.validate
  return true
end

.validate_json(schema, data, opts = {}) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 373

def validate_json(schema, data, opts={})
  validate(schema, data, opts.merge(:json => true))
end

.validate_json!(schema, data, opts = {}) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 388

def validate_json!(schema, data, opts={})
  validate!(schema, data, opts.merge(:json => true))
end

.validate_uri(schema, data, opts = {}) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 377

def validate_uri(schema, data, opts={})
  validate(schema, data, opts.merge(:uri => true))
end

.validate_uri!(schema, data, opts = {}) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 392

def validate_uri!(schema, data, opts={})
  validate!(schema, data, opts.merge(:uri => true))
end

.validatorsObject



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# File 'lib/json-schema/validator.rb', line 432

def validators
  @@validators
end

.version_string_for(version) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 123

def self.version_string_for(version)
  # I'm not a fan of this, but it's quick and dirty to get it working for now
  return "draft-04" unless version
  case version.to_s
  when "draft4", "http://json-schema.org/draft-04/schema#"
    "draft-04"
  when "draft3", "http://json-schema.org/draft-03/schema#"
    "draft-03"
  when "draft2"
    "draft-02"
  when "draft1"
    "draft-01"
  else
    raise JSON::Schema::SchemaError.new("The requested JSON schema version is not supported")
  end
end

Instance Method Details

#build_schemas(parent_schema) ⇒ Object

Build all schemas with IDs, mapping out the namespace



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# File 'lib/json-schema/validator.rb', line 265

def build_schemas(parent_schema)
  # Build ref schemas if they exist
  if parent_schema.schema["$ref"]
    load_ref_schema(parent_schema, parent_schema.schema["$ref"])
  end
  if parent_schema.schema["extends"]
    if parent_schema.schema["extends"].is_a?(String)
      load_ref_schema(parent_schema, parent_schema.schema["extends"])
    elsif parent_schema.schema["extends"].is_a?(Array)
      parent_schema.schema["extends"].each do |type|
        handle_schema(parent_schema, type)
      end
    end
  end

  # handle validations that always contain schemas
  ["allOf", "anyOf", "oneOf", "not"].each do |key|
    if parent_schema.schema.has_key?(key)
      validations = parent_schema.schema[key]
      validations = [validations] unless validations.is_a?(Array)
      validations.each {|v| handle_schema(parent_schema, v) }
    end
  end

  # Check for schemas in union types
  ["type", "disallow"].each do |key|
    if parent_schema.schema[key] && parent_schema.schema[key].is_a?(Array)
      parent_schema.schema[key].each_with_index do |type,i|
        if type.is_a?(Hash)
          handle_schema(parent_schema, type)
        end
      end
    end
  end

  # "definitions" are schemas in V4
  if parent_schema.schema["definitions"]
    parent_schema.schema["definitions"].each do |k,v|
      handle_schema(parent_schema, v)
    end
  end

  # All properties are schemas
  if parent_schema.schema["properties"]
    parent_schema.schema["properties"].each do |k,v|
      handle_schema(parent_schema, v)
    end
  end
  if parent_schema.schema["patternProperties"]
    parent_schema.schema["patternProperties"].each do |k,v|
      handle_schema(parent_schema, v)
    end
  end

  # Items are always schemas
  if parent_schema.schema["items"]
    items = parent_schema.schema["items"].clone
    single = false
    if !items.is_a?(Array)
      items = [items]
      single = true
    end
    items.each_with_index do |item,i|
      handle_schema(parent_schema, item)
    end
  end

  # Each of these might be schemas
  ["additionalProperties", "additionalItems", "dependencies", "extends"].each do |key|
    if parent_schema.schema[key].is_a?(Hash)
      handle_schema(parent_schema, parent_schema.schema[key])
    end
  end

end

#handle_schema(parent_schema, obj) ⇒ Object

Either load a reference schema or create a new schema



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# File 'lib/json-schema/validator.rb', line 342

def handle_schema(parent_schema, obj)
  if obj.is_a?(Hash)
    schema_uri = parent_schema.uri.clone
    schema = JSON::Schema.new(obj,schema_uri,parent_schema.validator)
    if obj['id']
      Validator.add_schema(schema)
    end
    build_schemas(schema)
  end
end

#load_ref_schema(parent_schema, ref) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 227

def load_ref_schema(parent_schema,ref)
  uri = URI.parse(ref)
  if uri.relative?
    uri = parent_schema.uri.clone

    # Check for absolute path
    path = ref.split("#")[0]

    # This is a self reference and thus the schema does not need to be re-loaded
    if path.nil? || path == ''
      return
    end

    if path && path[0,1] == '/'
      uri.path = Pathname.new(path).cleanpath.to_s
    else
      uri = parent_schema.uri.merge(path)
    end
    uri.fragment = ''
  end

  if Validator.schemas[uri.to_s].nil?
    begin
      schema = JSON::Schema.new(JSON::Validator.parse(open(uri.to_s).read), uri, @options[:version])
      Validator.add_schema(schema)
      build_schemas(schema)
    rescue JSON::ParserError
      # Don't rescue this error, we want JSON formatting issues to bubble up
      raise $!
    rescue Exception
      # Failures will occur when this URI cannot be referenced yet. Don't worry about it,
      # the proper error will fall out if the ref isn't ever defined
    end
  end
end

#schema_from_fragment(base_schema, fragment) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 183

def schema_from_fragment(base_schema, fragment)
  fragments = fragment.split("/")

  # ensure the first element was a hash, per the fragment spec
  if fragments.shift != "#"
    raise JSON::Schema::SchemaError.new("Invalid fragment syntax in :fragment option")
  end

  fragments.each do |f|
    if base_schema.is_a?(Hash)
      if !base_schema.has_key?(f)
        raise JSON::Schema::SchemaError.new("Invalid fragment resolution for :fragment option")
      end
      base_schema = base_schema[f]
    elsif base_schema.is_a?(Array)
      if base_schema[f.to_i].nil?
        raise JSON::Schema::SchemaError.new("Invalid fragment resolution for :fragment option")
      end
      base_schema = base_schema[f.to_i]
    else
      raise JSON::Schema::SchemaError.new("Invalid schema encountered when resolving :fragment option")
    end
  end

  base_schema
end

#validateObject

Run a simple true/false validation of data against a schema



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# File 'lib/json-schema/validator.rb', line 211

def validate()
  begin
    @base_schema.validate(@data,[],self,@validation_options)
    Validator.clear_cache
    if @options[:errors_as_objects]
      return @errors.map{|e| e.to_hash}
    else
      return @errors.map{|e| e.to_string}
    end
  rescue JSON::Schema::ValidationError
    Validator.clear_cache
    raise $!
  end
end

#validation_error(error) ⇒ Object



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# File 'lib/json-schema/validator.rb', line 353

def validation_error(error)
  @errors.push(error)
end

#validation_errorsObject



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# File 'lib/json-schema/validator.rb', line 357

def validation_errors
  @errors
end