Validation

The library extends vee-validate with metadata-driven rules and message resolution.

Built-in Rules

The core package registers XSD-inspired rules such as:

• xsd_required
• xsd_minOccurs
• xsd_choiceMinOccurs
• xsd_minLength
• xsd_maxLength
• xsd_length
• xsd_pattern
• xsd_minInclusive
• xsd_maxInclusive
• xsd_minExclusive
• xsd_maxExclusive
• xsd_enumeration
• xsd_whiteSpace
• xsd_fractionDigits
• xsd_totalDigits

These rules are attached automatically based on metadata.

Message Sources

Messages resolve in this order:

1. settings.messages
2. vee-validate configure({ generateMessage })
3. default rule output

The message resolver supports:

• positional placeholders like {0}
• named placeholders like {min}, {length}, {digits}
• context placeholders like {field}

Custom Validation

You can still provide custom vee-validate validation expressions in metadata:

{
  name: 'text',
  type: 'text',
  validation: 'xsd_minLength:3|xsd_maxLength:10',
}

The library splits multi-rule expressions into separate validation functions so multiple errors can be collected consistently.

Example Configuration

const settings = {
  messages: {
    required: '{field} is required',
    minOccurs: 'At least {min} items required',
    choiceMinOccurs: 'Select at least {min} value(s) in {field}',
    minLength: 'The minimum length of {field} is {length}',
  },
};

Interactive Example

Field 1 *

Field 2 *

IsDirty: false
Touched: false
Valid: true

// form values:
{}