# new TypeValidator(messageopt)
The TypeValidator ensures that a value matches one of the specified types. It can validate against a single type, multiple types, or a type with a specific name. This validator is typically used with the @type decorator and is fundamental for ensuring type safety in validated models.
Validator for checking if a value is of the expected type(s)
Parameters:
| Name | Type | Attributes | Description |
|---|---|---|---|
message |
string
|
<optional> |
Custom error message to display when validation fails, defaults to |
Example
```typescript
// Create a type validator with default error message
const typeValidator = new TypeValidator();
// Create a type validator with custom error message
const customTypeValidator = new TypeValidator("Value must be of type {0}, but got {1}");
// Validate against a single type
const stringOptions = { types: "string" };
typeValidator.hasErrors("hello", stringOptions); // undefined (valid)
typeValidator.hasErrors(123, stringOptions); // Returns error message (invalid)
// Validate against multiple types
const multiOptions = { types: ["string", "number"] };
typeValidator.hasErrors("hello", multiOptions); // undefined (valid)
typeValidator.hasErrors(123, multiOptions); // undefined (valid)
typeValidator.hasErrors(true, multiOptions); // Returns error message (invalid)
// Validate against a class type
const classOptions = { types: { name: "Date" } };
typeValidator.hasErrors(new Date(), classOptions); // undefined (valid)
```Extends
Methods
# hasErrors(value, options) → {string|undefined}
Validates that the provided value matches one of the specified types. It uses the Reflection utility to evaluate if the value's type matches the expected types. The method skips validation for undefined values to avoid conflicts with the RequiredValidator.
Checks if a value is of the expected type(s)
Parameters:
| Name | Type | Description |
|---|---|---|
value |
any
|
The value to validate |
options |
TypeValidatorOptions
|
Configuration options containing the expected types |
- Overrides:
- See:
View Source validation/Validators/TypeValidator.ts, line 146
Error message if validation fails, undefined if validation passes
string
|
undefined