Complex Validation Patterns

This guide covers advanced validation scenarios that go beyond simple field validation.

Conditional Validation

For basic conditional validation patterns, like making fields required based on other field values, see the Common Validation Patterns guide.

Here's an example of more complex conditions:

const validator = factory.make({
  'subscription': 'required|in_list:basic,premium',
  'storage_gb': 'required|integer|min:5',
  'max_users': 'required_if:subscription,premium|integer|min:5'
})

Interdependent Field Validation

When the validation rule for one field depends on the value of another field, you can use custom validation functions:

const validator = factory.make({
  'discount_type': 'required|in_list:percentage,fixed',
  'discount_value': [
    { name: 'required', rule: new RequiredRule() },
    { name: 'number', rule: new NumberRule() },
    { 
      name: 'max',
      rule: new FunctionBasedRule((value, path, datasource) => {
        const type = datasource.discount_type
        const price = datasource.price
        
        if (type === 'percentage') {
          return Number(value) <= 100
        } else {
          return Number(value) <= Number(price)
        }
      })
    }
  ]
})

Dynamic Array Validation

This example shows how to validate array items with rules that depend on properties of each item:

const validator = factory.make({
  // Product validation
  'products.*.sku': 'required|matches:^[A-Z]{2}\\d{6}$',
  'products.*.name': 'required|min_length:3',
  'products.*.type': 'required|in_list:digital,physical,service',
  'products.*.price': 'required|number|min:0',
  'products.*.categories.*.': 'required|min_length:2',
  
  // Quantity validation based on product type
  'products.*.quantity': [
    { name: 'required', rule: new RequiredRule() },
    { name: 'integer', rule: new IntegerRule() },
    { 
      name: 'max',
      rule: new FunctionBasedRule((value, path, datasource) => {
        // Extract product index from path
        const match = path.match(/products\[(\d+)\]/)
        if (!match) return true
        
        const index = match[1]
        const type = datasource.products[index].type
        
        // Different maximum quantities by type
        const maxQuantities = {
          digital: 5,
          physical: 10,
          service: 1
        }
        
        return Number(value) <= (maxQuantities[type] || 999)
      })
    }
  ]
})

Related Topics

• For more information on creating custom validation functions, see Custom Rules
• For validation of form inputs, see Form Validation