defaults

README

Defaults

Provide some global default values.

Documentation

Overview

Package defaults provides some global default values.

Index

• Variables
• func GetHTTPRequest(ctx context.Context, req interface{}) *http.Request
• func GetHTTPStatusCode(ctx context.Context, w http.ResponseWriter, r *http.Request) int
• func GetRemoteAddr(ctx context.Context, req interface{}) string
• func GetRequestID(ctx context.Context, req interface{}) string
• func GetStructFieldName(sf reflect.StructField) (name, arg string)
• func HTTPIsResponded(ctx context.Context, w http.ResponseWriter, r *http.Request) bool
• func HandlePanic(r interface{})
• func Now() time.Time
• func ValidateStruct(value interface{}) (err error)
• func ValidateWithRule(value interface{}, rule string) (err error)
• type Value
  • func NewValue[T any](initial T) *Value[T]
  • func NewValueWithValidation[T any](initial T, validate func(T) error) *Value[T]
  • func (v *Value[T]) Get() T
  • func (v *Value[T]) Set(new T)
  • func (v *Value[T]) Swap(new T) (old T)
  • func (v *Value[T]) Validate(value T) error

Variables

var (
	// HTTPIsRespondedFunc is used to report whether the http response is responded.
	//
	// For the default implementation, it will try check http.ResponseWriter:
	//   1. Check whether it implements the interface{ WroteHeader() bool } and return it.
	//   2. Check whether it implements the interface{ Unwrap() http.ResponseWriter } and retry 1.
	//   3. Return false instead.
	HTTPIsRespondedFunc = NewValueWithValidation(httpIsResponded, httpIsRespondedValidateFunc)

	// GetHTTPStatusCodeFunc is used to get the status code of the http response.
	//
	// For the default implementation, it will try check http.ResponseWriter:
	//   1. Check whether it implements the interface{ StatusCode() int } and return it.
	//   2. Check whether it implements the interface{ Unwrap() http.ResponseWriter } and retry 1.
	//   3. Return 200 instead.
	GetHTTPStatusCodeFunc = NewValueWithValidation(getHTTPStatusCode, getHTTPStatusCodeValidateFunc)

	// GetHTTPRequestFunc is used to get the http request from the request context.
	//
	// For the default implementation, it only detects req
	// and supports the types or interfaces:
	//
	//	*http.Request
	//	interface{ Request() *http.Request }
	//	interface{ HTTPRequest() *http.Request }
	//	interface{ GetRequest() *http.Request }
	//	interface{ GetHTTPRequest() *http.Request }
	//
	// If not found, return nil.
	GetHTTPRequestFunc = NewValueWithValidation(getHTTPRequest, reqValidateFunc)
)

var (
	// HeaderXRequestID is used by GetRequestIDFunc to try
	// to get the request id from the http request.
	HeaderXRequestID = "X-Request-Id"

	// GetRequestIDFunc is used to get the unique request session id.
	//
	// For the default implementation, it only detects req
	// and supports the interfaces:
	//
	//	interface{ RequestID() string }
	//	interface{ GetRequestID() string }
	//
	// or, retry to get the http request by GetHTTPRequestFunc
	// and return the header HeaderXRequestID.
	//
	// Return "" instead if not found.
	GetRequestIDFunc = NewValueWithValidation(getRequestID, reqidValidateFunc)

	// GetRemoteAddrFunc is used to get the remote address.
	//
	// For the default implementation, it only detects req
	// and supports the types or interfaces:
	//
	//	interface{ RemoteAddr() string }
	//	interface{ RemoteAddr() net.Addr }
	//	interface{ RemoteAddr() netip.AddrPort }
	//
	// or, retry to get the http request by GetHTTPRequestFunc
	// and return the field RemoteAddr.
	GetRemoteAddrFunc = NewValueWithValidation(getRemoteAddr, raddrValidateFunc)
)

var (
	TimeFormat   = NewValueWithValidation(time.RFC3339Nano, validateTimeFormat)
	TimeFormats  = NewValueWithValidation([]string{time.RFC3339Nano, "2006-01-02 15:04:05"}, validateTimeFormats)
	TimeLocation = NewValueWithValidation(time.UTC, validateTimeLocation)
	TimeNowFunc  = NewValueWithValidation(time.Now, validateTimeNow)
)

Pre-define some global variables about time.

var (
	// RuleValidator is used to validate whether a value conforms with the rule.
	//
	// Note: in general, it is used to validate a struct field with the tag rule.
	RuleValidator = NewValue(assists.RuleValidator(nil))

	// StructValidator is used to validate whether a struct value is valid.
	StructValidator = NewValue(assists.StructValidator(nil))
)

var (
	// HandlePanicFunc is used to handle the panic value returned by recover().
	//
	// Default: log.Printf("wrap a panic: %+v", recoverValue)
	HandlePanicFunc = NewValueWithValidation(handlePanic, handlePanicValidation)
)

var (
	// StructFieldNameFunc is used to get the obtain the name and arg
	// of the struct field, which needs to return a empty string for
	// the field name, that's "", if the field should be ignored.
	//
	// Example:
	//
	//	StructFieldNameFunc.Set(func(sf reflect.StructField) (name string, arg string) {
	//	    value := sf.Tag.Get("json")
	//	    if index := strings.IndexByte(value, ','); index > -1 {
	//	        arg = strings.TrimSpace(value[index+1:])
	//	        value = strings.TrimSpace(value[:index])
	//	    }
	//
	//	    switch value {
	//	    case "-":
	//	    case "":
	//	        name = sf.Name
	//	    default:
	//	        name = value
	//	    }
	//
	//	    return
	//	})
	//
	StructFieldNameFunc = NewValueWithValidation(assists.StructFieldNameFuncWithTags("json"), validateStructFieldName)
)

Functions

func GetHTTPRequest

func GetHTTPRequest(ctx context.Context, req interface{}) *http.Request

GetHTTPRequest is the proxy of GetHTTPRequestFunc to call the function.

func GetHTTPStatusCode

func GetHTTPStatusCode(ctx context.Context, w http.ResponseWriter, r *http.Request) int

GetHTTPStatusCode is the proxy of GetHTTPStatusCodeFunc to call the function.

func GetRemoteAddr

func GetRemoteAddr(ctx context.Context, req interface{}) string

GetRemoteAddr is the proxy of GetRemoteAddrFunc to call the function.

func GetRequestID

func GetRequestID(ctx context.Context, req interface{}) string

GetRequestID is the proxy of GetRequestIDFunc to call the function.

func GetStructFieldName

func GetStructFieldName(sf reflect.StructField) (name, arg string)

GetStructFieldName is the proxy of StructFieldNameFunc to call the function, just like StructFieldNameFunc.Get()(sf).

func HTTPIsResponded

func HTTPIsResponded(ctx context.Context, w http.ResponseWriter, r *http.Request) bool

HTTPIsResponded is the proxy of HTTPIsRespondedFunc to call the function.

func HandlePanic

func HandlePanic(r interface{})

HandlePanic is the proxy of HandlePanicFunc to call the funciton.

func Now

func Now() time.Time

Now returns the current time by using TimeNow and TimeLocation.

func ValidateStruct

func ValidateStruct(value interface{}) (err error)

ValidateStruct uses Validator to validate the struct value if StructValidator is not nil.

func ValidateWithRule

func ValidateWithRule(value interface{}, rule string) (err error)

ValidateWithRule uses RuleValidator to validate a value conforms with the rule if RuleValidator is not nil.

Types

type Value

type Value[T any] struct {
	// contains filtered or unexported fields
}

Value represents a common value.

func NewValue

func NewValue[T any](initial T) *Value[T]

NewValue returns a new Value with the initial value.

func NewValueWithValidation

func NewValueWithValidation[T any](initial T, validate func(T) error) *Value[T]

NewValueWithValidation returns a new Value with the initial value and the validation.

validate may be nil, which is equal to always return nil.

func (*Value[T]) Get

func (v *Value[T]) Get() T

Get returns the inner value.

func (*Value[T]) Set

func (v *Value[T]) Set(new T)

Set sets the value to new thread-safely.

It will panic if failing to validate the new value.

func (*Value[T]) Swap

func (v *Value[T]) Swap(new T) (old T)

Swap sets the value to new thread-safely and returns the old value.

It will panic if failing to validate the new value.

func (*Value[T]) Validate

func (v *Value[T]) Validate(value T) error

Validate validate whether the input value is valid.