Data types

The business objects have their own data types. All data types can have null value. They inherits the DataType class, this way they implements two abstract methods:

parse( value )
It checks whether the value conforms to the data type definition. Returns the value when it has the required data type. If not, but it can be converted into the required data type, then returns the converted value. Otherwise returns undefined to mark the value as invalid.
hasValue( value )
It checks if the data type of the value conforms to the data type definition and it is not null.

The library provides the following data types:

Name	Description
Boolean	Represents a Boolean value, i.e. true, false or null.
Text	Represents any string, including empty string and null.
Email	Represents an e-mail address of format name@domain.tld or null.
Integer	Represents an integer or null.
Decimal	Represents any number or null.
Enum	Represents an enumeration value or null. See Enumerations page for more information.
DateTime	Represents a date and time value or null.

Custom types can be created inheriting DataType class and overriding parse() and hasValue() methods. The example below provides a time data type in hh:mm and h:mm format.

var util = require('util');
var bo = require('business-objects');

var DataType = bo.dataTypes.DataType;
var reTime = /^([0-9]|0[0-9]|1[0-9]|2[0-3]):[0-5][0-9]$/;

// Define Time class.
function Time () {
  DataType.call(this);
}
util.inherits(Time, DataType);

// Override parse() function.
Time.prototype.parse = function (value) {

  // Test whether input has value.
  if (value === null || value === undefined)
    return null;

  // Normalize input value.
  var time;
  if (typeof value === 'string')
    time = value;
  else if (value instanceof String)
    time = value.valueOf();
  else
    time = new String(value).valueOf();

  // Check input value.
  return time.length && reTime.test(time) ? time : undefined;
};

// Override hasValue() function.
Time.prototype.hasValue = function (value) {

  // Evaluate input value.
  var parsed = this.parse(value);
  return parsed !== undefined && parsed !== null;
};