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
}
@@validators = 
{}
@@default_validator = 
nil
@@available_json_backends = 
[]
@@json_backend = 
'yajl'
@@errors = 
[]
@@serializer = 
lambda{|o| Marshal.dump(o) }

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 140

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

  # I'm not a fan of this, but it's quick and dirty to get it working for now
  version_string = "draft-03"
  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} : {}
  
  # validate the schema, if requested
  if @options[:validate_schema]
    begin
      meta_validator = JSON::Validator.new(self.class.metaschema_for(version_string), schema_data)
      meta_validator.validate
    rescue JSON::Schema::ValidationError, JSON::Schema::SchemaError
      raise $!
    end
  end
  
  @base_schema = initialize_schema(schema_data)
  @data = initialize_data(data)
  build_schemas(@base_schema)
end

Class Method Details

.add_schema(schema) ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 335

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 339

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

.clear_cache ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 315

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

.clear_errors ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 319

def clear_errors
  @@errors = []
end

.default_validator ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 347

def default_validator
  @@default_validator
end

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



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# File 'lib/json-schema/validator.rb', line 302

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

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



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# File 'lib/json-schema/validator.rb', line 308

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

.json_backend ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 359

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

.json_backend=(backend) ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 367

def json_backend=(backend)
  if defined?(MultiJson)
    backend = backend == 'json' ? 'json_gem' : 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 136

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 381

def parse(s)
  if defined?(MultiJson)
    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 355

def register_default_validator(v)
  @@default_validator = v
end

.register_validator(v) ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 351

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

.schemas ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 331

def schemas
  @@schemas
end

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



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# File 'lib/json-schema/validator.rb', line 284

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 294

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

.validation_error(error) ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 323

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

.validation_errors ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 327

def validation_errors
  @@errors
end

.validators ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 343

def validators
  @@validators
end

.version_string_for(version) ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 121

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-03" unless version
  case version.to_s
  when "draft3"
    "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 226

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

  # 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

  # All properties are schemas
  if parent_schema.schema["properties"]
    parent_schema.schema["properties"].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 273

def handle_schema(parent_schema, obj)
  schema_uri = parent_schema.uri.clone
  schema = JSON::Schema.new(obj,schema_uri,@options[:version])
  if obj['id']
    Validator.add_schema(schema)
  end
  build_schemas(schema)
end

#load_ref_schema(parent_schema, ref) ⇒ Object 



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# File 'lib/json-schema/validator.rb', line 188

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

#validate ⇒ Object

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



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# File 'lib/json-schema/validator.rb', line 171

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