@ -9,6 +9,7 @@
package validator
import (
"bytes"
"errors"
"fmt"
"reflect"
@ -28,7 +29,8 @@ const (
validationStructErrMsg = "Struct:%s\n"
)
// FieldValidationError contains a single fields validation error
// FieldValidationError contains a single field's validation error along
// with other properties that may be needed for error message creation
type FieldValidationError struct {
Field string
ErrorTag string
@ -44,7 +46,8 @@ func (e *FieldValidationError) Error() string {
return fmt . Sprintf ( validationFieldErrMsg , e . Field , e . ErrorTag )
}
// StructValidationErrors is hierarchical list of field and struct errors
// StructValidationErrors is hierarchical list of field and struct validation errors
// for a non hierarchical representation please see the Flatten method for StructValidationErrors
type StructValidationErrors struct {
// Name of the Struct
Struct string
@ -58,21 +61,20 @@ type StructValidationErrors struct {
// This is intended for use in development + debugging and not intended to be a production error message.
// it also allows StructValidationErrors to be used as an Error interface
func ( e * StructValidationErrors ) Error ( ) string {
s := fmt . Sprintf ( validationStructErrMsg , e . Struct )
buff := bytes . NewBufferString ( fmt . Sprintf ( validationStructErrMsg , e . Struct ) )
for _ , err := range e . Errors {
s += err . Error ( )
buff . WriteString ( err . Error ( ) )
}
for _ , sE rr:= range e . StructErrors {
s += sE rr. Error ( )
for _ , e rr:= range e . StructErrors {
buff . WriteString ( e rr. Error ( ) )
}
return fmt . Sprintf ( "%s\n\n" , s )
buff . WriteString ( "\n\n" )
return buff . String ( )
}
// Flatten flattens the StructValidationErrors hierarchical sc tructure into a flat namespace style field name
// Flatten flattens the StructValidationErrors hierarchical structure into a flat namespace style field name
// for those that want/need it
func ( e * StructValidationErrors ) Flatten ( ) map [ string ] * FieldValidationError {
@ -110,17 +112,16 @@ type ValidationFunc func(top interface{}, current interface{}, f interface{}, pa
// Validator implements the Validator Struct
// NOTE: Fields within are not thread safe and that is on purpose
// Functions Tags etc. should all be predifined before use, so subscribe to the philosiphy
// Functions and Tags should all be predifined before use, so subscribe to the philosiphy
// or make it thread safe on your end
type Validator struct {
// T agName being used.
// t agName being used.
tagName string
// validationFuncs is a map of validation functions and the tag keys
validationFuncs map [ string ] ValidationFunc
}
// NewValidator creates a new Validator instance
// NOTE: it is not necessary to create a new validator as the internal one will do in 99.9% of cases, but the option is there.
// NewValidator creates a new Validator instance for use.
func NewValidator ( tagName string , funcs map [ string ] ValidationFunc ) * Validator {
return & Validator {
tagName : tagName ,
@ -128,12 +129,14 @@ func NewValidator(tagName string, funcs map[string]ValidationFunc) *Validator {
}
}
// SetTag sets tagName of the Validator to one of your choosing
// SetTag sets tagName of the Validator to one of your choosing after creation
// perhaps to dodge a tag name conflict in a specific section of code
func ( v * Validator ) SetTag ( tagName string ) {
v . tagName = tagName
}
// AddFunction adds a ValidationFunc to a Validator's map of validators denoted by the key
// NOTE: if the key already exists, it will get replaced.
func ( v * Validator ) AddFunction ( key string , f ValidationFunc ) error {
if len ( key ) == 0 {
@ -141,38 +144,30 @@ func (v *Validator) AddFunction(key string, f ValidationFunc) error {
}
if f == nil {
return errors . New ( "Function Key cannot be empty" )
return errors . New ( "Function cannot be empty" )
}
// Commented out to allow overwritting of Baked In Function if so desired.
// if v.ValidationFuncs[key] != nil {
// return errors.New(fmt.Sprintf("Validation Function with key: %s already exists.", key))
// }
v . validationFuncs [ key ] = f
return nil
}
// ValidateStruct validates a struct and returns a struct containing the errors
// ValidateStruct validates a struct, even it's nested structs, and returns a struct containing the errors
// NOTE: Nested Arrays, or Maps of structs do not get validated only the Array or Map itself; the reason is that there is no good
// way to represent or report which struct within the array has the error, besides can validate the struct prior to adding it to
// the Array or Map.
func ( v * Validator ) ValidateStruct ( s interface { } ) * StructValidationErrors {
return v . validateStructRecursive ( s , s , s )
}
// validateStructRecursive validates a struct recursivly and passes the top level struct around for use in validator functions and returns a struct containing the errors
// validateStructRecursive validates a struct recursivly and passes the top level and current struct around for use in validator functions and returns a struct containing the errors
func ( v * Validator ) validateStructRecursive ( top interface { } , current interface { } , s interface { } ) * StructValidationErrors {
structValue := reflect . ValueOf ( s )
structType := reflect . TypeOf ( s )
structName := structType . Name ( )
validationErrors := & StructValidationErrors {
Struct : structName ,
Errors : map [ string ] * FieldValidationError { } ,
StructErrors : map [ string ] * StructValidationErrors { } ,
}
if structValue . Kind ( ) == reflect . Ptr && ! structValue . IsNil ( ) {
return v . validateStructRecursive ( top , current , structValue . Elem ( ) . Interface ( ) )
}
@ -181,6 +176,12 @@ func (v *Validator) validateStructRecursive(top interface{}, current interface{}
panic ( "interface passed for validation is not a struct" )
}
validationErrors := & StructValidationErrors {
Struct : structName ,
Errors : map [ string ] * FieldValidationError { } ,
StructErrors : map [ string ] * StructValidationErrors { } ,
}
var numFields = structValue . NumField ( )
for i := 0 ; i < numFields ; i ++ {
@ -255,7 +256,7 @@ func (v *Validator) ValidateFieldByTag(f interface{}, tag string) *FieldValidati
return v . ValidateFieldByTagAndValue ( nil , f , tag )
}
// ValidateFieldByTagAndValue allows validation of a single field, still using tag style validation to check multiple errors
// ValidateFieldByTagAndValue allows validation of a single field, possibly even against another fields value, still using tag style validation to check multiple errors
func ( v * Validator ) ValidateFieldByTagAndValue ( val interface { } , f interface { } , tag string ) * FieldValidationError {
return v . validateFieldByNameAndTagAndValue ( nil , val , f , "" , tag )
Dean Karn
10 years ago