unimatrixzxero's posterous

Validations invoked after create, save and updateAttributes, it also possible to skip validations when use save method:

obj.save({validate: false});

Validations can be called manually using isValid method of object

Normally all validations result in errors member of object, which is a hash of arrays of error messages:

obj.errors 
{
    email: [
        'can\'t be blank',
        'format is invalid'
    ],
    password: [ 'too short' ]
}

It also can raise exception, if you want, just pass throws: true as param of save method:

// be carefull, now it will throw Error object
obj.save({throws: true});

To setup validation, call it configurator on class:

Person.validatesPresenceOf('email', 'name')
Person.validatesLengthOf('password', {min: 5})

Each configurator accepts set of string arguments, and one optional last argument, which is actually specify how validator should work, of course it depends on each validator, but there's few common options:

• if
• unless
• message
• allowNull
• allowBlank

if and unless methods is for skipping validations depending on conditions, it can be function, or string. Function invoked in context of object, where validation performed. If string passed, then one of object's member checked.

message member allows to configure error message, it can be string or object (depends on validator), see usage examples

allowNull and allowBlank is self explanatory :)

Examples of different types of validations:

length

User.validatesLengthOf 'password', min: 3, max: 10, allowNull: true
User.validatesLengthOf 'state', is: 2, allowBlank: true
user = new User validAttributes

user.password = 'qw'
test.ok not user.isValid(), 'Invalid: too short'
test.equal user.errors.password[0], 'too short'

user.password = '12345678901'
test.ok not user.isValid(), 'Invalid: too long'
test.equal user.errors.password[0], 'too long'

user.password = 'hello'
test.ok user.isValid(), 'Valid with value'
test.ok not user.errors

user.password = null
test.ok user.isValid(), 'Valid without value'
test.ok not user.errors

user.state = 'Texas'
test.ok not user.isValid(), 'Invalid state'
test.equal user.errors.state[0], 'length is wrong'

user.state = 'TX'
test.ok user.isValid(), 'Valid with value of state'
test.ok not user.errors

numericality

User.validatesNumericalityOf 'age', int: true
user = new User validAttributes

user.age = '26'
test.ok not user.isValid(), 'User is not valid: not a number'
test.equal user.errors.age[0], 'is not a number'

user.age = 26.1
test.ok not user.isValid(), 'User is not valid: not integer'
test.equal user.errors.age[0], 'is not an integer'

user.age = 26
test.ok user.isValid(), 'User valid: integer age'
test.ok not user.errors

inclusion

User.validatesInclusionOf 'gender', in: ['male', 'female']
user = new User validAttributes

user.gender = 'any'
test.ok not user.isValid()
test.equal user.errors.gender[0], 'is not included in the list'

user.gender = 'female'
test.ok user.isValid()

user.gender = 'male'
test.ok user.isValid()

user.gender = 'man'
test.ok not user.isValid()
test.equal user.errors.gender[0], 'is not included in the list'

exclusion

User.validatesExclusionOf 'domain', in: ['www', 'admin']
user = new User validAttributes

user.domain = 'www'
test.ok not user.isValid()
test.equal user.errors.domain[0], 'is reserved'

user.domain = 'my'
test.ok user.isValid()

format

User.validatesFormatOf 'email', with: /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i
user = new User validAttributes

user.email = 'invalid email'
test.ok not user.isValid()

user.email = 'valid@email.tld'
test.ok user.isValid()