Field validators

Validators ensure that field input is entered in correct format and length. For example, you can validate that an email address adheres to a syntax such as first.last@company.com. You can add multiple validators to a field. The validators are executed like a chain, one after the other.

Common validator properties

Simple validator definition:

form:
  tabs:
    - name: tabUser
      label: User info
      fields:
        - name: emailAddress
          fieldType: text
          label: Email
          validators:
            - name: email
              class: info.magnolia.ui.form.validator.definition.EmailValidatorDefinition
              errorMessage: Enter a valid email address

Properties:

allowedAttributes:
  abbr:
    tag: a
    attributes: [ title ]

allowedAttributes:
  a:
    tag: a
    attributes: [ href ]
allowedProtocols:
  a:
    tag: a
    attribute: href
    protocols: [ https, mailto ]

List of validator definition classes

Custom regular expressions

The easiest custom validator is a regular expression. Use the RegexpValidatorDefinition class and define your own regular expression in the pattern property.

Here is an example of validating a ZIP code (U.S. postal code).

form:
  tabs:
    - name: tabUser
      label: User info
      fields:
        - name: zipCode
          fieldType: text
          label: Zip code
          validators:
            - name: zip
              class: info.magnolia.ui.form.validator.definition.RegexpValidatorDefinition
              pattern: ^\d{5}(-\d{4})?$
              errorMessage: Enter a valid U.S. ZIP code using the format 12345 or 12345-1234

Custom validators

To write your own validator class:

1. Create a validator class that performs the actual validation. 
2. Create a validator factory class that extends AbstractFieldValidatorFactory . Implement the createValidator method.
3. Create a validator definition class that extends ConfiguredFieldValidatorDefinition . In the definition class, set the factory class.

Example: Checking that a username is unique.

• UniqueUserNameValidator
• UniqueUserNameValidatorFactory
• UniqueUserNameValidatorDefinition

Checking for null values

field: ${field!"value not provided"}