Documentation
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Overview ¶
Package base provides the core interfaces and implementations for value objects.
This package serves as the foundation for the valueobject framework, defining the essential interfaces that all value objects should implement and providing base implementations for common value object types.
Key interfaces defined in this package:
- ValueObject: The base interface for all value objects, defining methods for string representation and emptiness checking.
- Equatable: For value objects that can be compared for equality.
- Comparable: For value objects that can be compared for ordering.
- Validatable: For value objects that can be validated.
- JSONMarshallable: For value objects that can be marshalled to JSON.
- JSONUnmarshallable: For value objects that can be unmarshalled from JSON.
Base implementations provided:
- StringValueObject: A base implementation for string-based value objects.
- StructValueObject: A base implementation for struct-based value objects.
The package also provides utility functions for common value object operations and validation helpers to ensure value objects maintain their invariants.
Example usage:
// Define a custom string-based value object
type Email struct {
base.StringValueObject
}
// Create a constructor with validation
func NewEmail(value string) (*Email, error) {
// Create the value object
email := &Email{}
// Initialize with validation
if err := email.Init(value); err != nil {
return nil, err
}
// Additional validation
if !strings.Contains(value, "@") {
return nil, errors.New("invalid email format")
}
return email, nil
}
The base package is designed to be extended by more specific value object types in other subpackages, providing a consistent foundation for all value objects in the application.
Package base provides common interfaces and utilities for value objects.
Package base provides common interfaces and utilities for value objects.
Package base provides common interfaces and utilities for value objects.
Package base provides common interfaces and utilities for value objects.
Package base provides common interfaces and utilities for value objects.
Index ¶
- Variables
- func CompareFloats(a, b float64) int
- func CompareStrings(a, b string) int
- func FloatsEqual(a, b float64) bool
- func IsEmptyString(s string) bool
- func IsZeroFloat(f float64) bool
- func RoundFloat(f float64, places int) float64
- func StringsEqualFold(a, b string) bool
- func TrimAndNormalize(s string) string
- func ValidateCurrencyCode(code string) error
- func ValidateEmail(email string) error
- func ValidatePhone(phone string) error
- func ValidateURL(url string) error
- func ValidateUsername(username string) error
- func WithValidation[T any](vo T, err error) (T, error)
- type BaseStructValueObject
- type Comparable
- type Equatable
- type JSONMarshallable
- type JSONUnmarshallable
- type StringValueObject
- func (vo StringValueObject) Equals(other StringValueObject) bool
- func (vo StringValueObject) EqualsIgnoreCase(other StringValueObject) bool
- func (vo StringValueObject) IsEmpty() bool
- func (vo StringValueObject) String() string
- func (vo StringValueObject) Value() string
- func (vo StringValueObject) WithValue(value string) StringValueObject
- type StructValueObject
- type Validatable
- type ValueObject
Constants ¶
This section is empty.
Variables ¶
var ( // ErrEmptyValue is returned when a required value is empty. ErrEmptyValue = errors.New("value cannot be empty") // ErrInvalidFormat is returned when a value has an invalid format. ErrInvalidFormat = errors.New("invalid format") // ErrOutOfRange is returned when a value is out of the allowed range. ErrOutOfRange = errors.New("value out of allowed range") )
var ( // EmailRegex is a regular expression for validating email addresses. EmailRegex = regexp.MustCompile(`^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$`) // URLRegex is a regular expression for validating URLs. URLRegex = regexp.MustCompile(`^(https?|ftp)://[^\s/$.?#].[^\s]*$`) // PhoneRegex is a regular expression for validating phone numbers. PhoneRegex = regexp.MustCompile(`^\+?[0-9]{1,3}[-\s]?[0-9]{1,14}$`) // UsernameRegex is a regular expression for validating usernames. UsernameRegex = regexp.MustCompile(`^[a-zA-Z0-9_-]{3,20}$`) // CurrencyCodeRegex is a regular expression for validating ISO currency codes. CurrencyCodeRegex = regexp.MustCompile(`^[A-Z]{3}$`) )
Common validation regular expressions
Functions ¶
func CompareFloats ¶
CompareFloats compares two float64 values with a small epsilon to handle floating point precision. Returns: -1 if a < b
0 if a == b 1 if a > b
func CompareStrings ¶
CompareStrings compares two strings case-insensitively. Returns: -1 if a < b
0 if a == b 1 if a > b
func FloatsEqual ¶
FloatsEqual checks if two float64 values are equal, with a small epsilon to handle floating point precision.
func IsEmptyString ¶
IsEmptyString checks if a string is empty after trimming whitespace.
func IsZeroFloat ¶
IsZeroFloat checks if a float64 is zero, with a small epsilon to handle floating point precision.
func RoundFloat ¶
RoundFloat rounds a float64 to the specified number of decimal places.
func StringsEqualFold ¶
StringsEqualFold checks if two strings are equal, ignoring case.
func TrimAndNormalize ¶
TrimAndNormalize trims whitespace and normalizes a string. This is useful for value objects that need to normalize their string representation.
func ValidateCurrencyCode ¶
ValidateCurrencyCode validates an ISO currency code.
func ValidateEmail ¶
ValidateEmail validates an email address.
func ValidateUsername ¶
ValidateUsername validates a username.
func WithValidation ¶
WithValidation is a helper function that validates a value object after creation. It's useful for constructor functions that need to validate the created object. Example usage:
func NewMyValueObject(value string) (MyValueObject, error) {
vo := MyValueObject{value: value}
return WithValidation(vo, vo.Validate())
}
Types ¶
type BaseStructValueObject ¶
type BaseStructValueObject struct{}
BaseStructValueObject is a base implementation of StructValueObject. It provides common functionality for struct-based value objects. Embed this struct in your value object to inherit its functionality.
func (BaseStructValueObject) IsEmpty ¶
func (vo BaseStructValueObject) IsEmpty() bool
IsEmpty checks if the value object is empty (zero value). This is a default implementation that always returns false. Override this method in your value object to provide a proper implementation.
func (BaseStructValueObject) MarshalJSON ¶
func (vo BaseStructValueObject) MarshalJSON() ([]byte, error)
MarshalJSON implements the json.Marshaler interface. This is a default implementation that uses the ToMap method. Override this method in your value object to provide a more efficient implementation.
func (BaseStructValueObject) String ¶
func (vo BaseStructValueObject) String() string
String returns the string representation of the value object. This is a default implementation that returns a generic string. Override this method in your value object to provide a proper implementation.
func (BaseStructValueObject) ToMap ¶
func (vo BaseStructValueObject) ToMap() map[string]interface{}
ToMap converts the value object to a map[string]interface{}. This is a default implementation that returns an empty map. Override this method in your value object to provide a proper implementation.
type Comparable ¶
type Comparable[T any] interface { // CompareTo compares this value object with another and returns: // -1 if this < other // 0 if this == other // 1 if this > other CompareTo(other T) int }
Comparable is an interface for value objects that can be compared for ordering.
type Equatable ¶
type Equatable[T any] interface { // Equals checks if two value objects are equal. Equals(other T) bool }
Equatable is an interface for value objects that can be compared for equality.
type JSONMarshallable ¶
type JSONMarshallable interface {
// MarshalJSON implements the json.Marshaler interface.
MarshalJSON() ([]byte, error)
}
JSONMarshallable is an interface for value objects that can be marshalled to JSON.
type JSONUnmarshallable ¶
type JSONUnmarshallable interface {
// UnmarshalJSON implements the json.Unmarshaler interface.
UnmarshalJSON(data []byte) error
}
JSONUnmarshallable is an interface for value objects that can be unmarshalled from JSON.
type StringValueObject ¶
type StringValueObject struct {
// contains filtered or unexported fields
}
StringValueObject is a base type for string-based value objects. It implements the ValueObject and Equatable interfaces.
func NewStringValueObject ¶
func NewStringValueObject(value string) StringValueObject
NewStringValueObject creates a new StringValueObject with the given value.
func (StringValueObject) Equals ¶
func (vo StringValueObject) Equals(other StringValueObject) bool
Equals checks if two StringValueObjects are equal. This is a case-sensitive comparison. For case-insensitive comparison, use EqualsIgnoreCase.
func (StringValueObject) EqualsIgnoreCase ¶
func (vo StringValueObject) EqualsIgnoreCase(other StringValueObject) bool
EqualsIgnoreCase checks if two StringValueObjects are equal, ignoring case.
func (StringValueObject) IsEmpty ¶
func (vo StringValueObject) IsEmpty() bool
IsEmpty checks if the value object is empty (zero value).
func (StringValueObject) String ¶
func (vo StringValueObject) String() string
String returns the string representation of the value object.
func (StringValueObject) Value ¶
func (vo StringValueObject) Value() string
Value returns the underlying string value.
func (StringValueObject) WithValue ¶
func (vo StringValueObject) WithValue(value string) StringValueObject
WithValue returns a new StringValueObject with the given value.
type StructValueObject ¶
type StructValueObject interface {
ValueObject
// ToMap converts the value object to a map[string]interface{}.
ToMap() map[string]interface{}
// MarshalJSON implements the json.Marshaler interface.
MarshalJSON() ([]byte, error)
}
StructValueObject is a base interface for struct-based value objects. It extends the ValueObject interface with methods specific to struct-based value objects.
type Validatable ¶
type Validatable interface {
// Validate checks if the value object is valid.
// Returns nil if valid, otherwise returns an error.
Validate() error
}
Validatable is an interface for value objects that can be validated.
type ValueObject ¶
type ValueObject interface {
// String returns the string representation of the value object.
String() string
// IsEmpty checks if the value object is empty (zero value).
IsEmpty() bool
}
ValueObject is the base interface for all value objects. It defines the common methods that all value objects should implement.
Source Files