Custom Message Replacements

CBValidation provides powerful message replacement functionality that allows you to create dynamic, context-aware error messages. You can use these replacements in both custom constraint messages and i18n resource bundles.

Global Replacements

These replacements are available for all validators:

• {rejectedValue} - The actual value that failed validation

• {field} or {property} - The name of the field being validated

• {validationType} - The name of the constraint validator (e.g., "Required", "Size", "Type")

• {validationData} - The constraint's configuration value (e.g., for size="5..10", this would be "5..10")

Validator-Specific Replacements

Each validator provides additional context-specific replacement variables accessible via the error metadata:

Numeric Validators

• {MaxValidator} - {max} - The maximum allowed value

• {MinValidator} - {min} - The minimum required value

• {RangeValidator} - {range}, {min}, {max} - Range boundaries

• {DiscreteValidator} - {operation}, {operationValue} - Math operation details

String & Collection Validators

• {SizeValidator} - {size}, {min}, {max} - Size constraints for strings, arrays, structs

• {TypeValidator} - {type} - Expected data type

• {RegexValidator} - {regex} - Regular expression pattern

• {InListValidator} - {inList} - Comma-separated list of valid values

Comparison Validators

• {SameAsValidator} - {sameas} - Field name for comparison

• {SameAsNoCaseValidator} - {sameas} - Field name for case-insensitive comparison

• {NotSameAsValidator} - {notsameas} - Field name that should be different

• {NotSameAsNoCaseValidator} - {notsameas} - Field name for case-insensitive difference check

Date Validators

• {AfterValidator} - {after} - Reference date or field name

• {BeforeValidator} - {before} - Reference date or field name

• {AfterOrEqualValidator} - {afterOrEqual} - Reference date or field name

• {BeforeOrEqualValidator} - {beforeOrEqual} - Reference date or field name

• {DateEqualsValidator} - {dateEquals} - Reference date or field name

Database & Uniqueness

• {UniqueValidator} - {table}, {column} - Database table and column being checked

Usage Examples

Basic Custom Messages

username = {
    required = true,
    requiredMessage = "Please enter your {field}",
    size = "3..20",
    sizeMessage = "The {field} must be between {min} and {max} characters"
}

Advanced Examples with Metadata

password = {
    required = true,
    size = "8..128",
    sizeMessage = "Password must be at least {min} characters (you entered {rejectedValue} characters)",
    regex = "^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)",
    regexMessage = "Password must contain uppercase, lowercase, and numbers (Pattern: {regex})"
},

age = {
    required = true,
    range = "18..65",
    rangeMessage = "Age must be between {min} and {max} years old (you entered: {rejectedValue})"
},

confirmPassword = {
    required = true,
    sameAs = "password",
    sameAsMessage = "Password confirmation must match your {sameas} field"
}

i18n Integration

You can use these replacements in your resource bundle files:

# resources/validation_en.properties
user.username.required=Please provide a {field} for your account
user.username.size={field} must be {min}-{max} characters (current: {rejectedValue})
user.age.range=Age must be {min} to {max} years (you entered {rejectedValue})
user.email.type=Please enter a valid {type} address in the {field} field

Error Metadata Access

Starting in CBValidation 4.3.0+, you can access all error metadata programmatically:

var result = validate(target=user, constraints="userValidation");
if (result.hasErrors()) {
    for (var error in result.getAllErrors()) {
        var metadata = error.getErrorMetadata();
        // metadata contains all the replacement variables
        // e.g., metadata.min, metadata.max, metadata.type, etc.
    }
}

This allows for dynamic error handling and custom error message generation based on the specific validation context.