From 207b714da8cace765dbf44fa6200b1ef06f085fe Mon Sep 17 00:00:00 2001
From: Dean Karn <Dean.Karn@metricaid.com>
Date: Fri, 13 Feb 2015 09:01:11 -0500
Subject: [PATCH] issue-#2

add Error interfaces to error structs
add const variable to production string variables.
---
 validator.go      | 27 +++++++++++++++++++++++++--
 validator_test.go |  1 +
 2 files changed, 26 insertions(+), 2 deletions(-)

diff --git a/validator.go b/validator.go
index e9f62b4..adbfeca 100644
--- a/validator.go
+++ b/validator.go
@@ -2,6 +2,7 @@ package validator
 
 import (
 	"errors"
+	"fmt"
 	"log"
 	"reflect"
 	"strings"
@@ -9,7 +10,9 @@ import (
 )
 
 const (
-	omitempty string = "omitempty"
+	defaultTagName          = "validate"
+	omitempty        string = "omitempty"
+	validationErrMsg        = "Field validation for \"%s\" failed on the \"%s\" tag\n"
 )
 
 // FieldValidationError contains a single fields validation error
@@ -18,6 +21,12 @@ type FieldValidationError struct {
 	ErrorTag string
 }
 
+// This is intended for use in development + debugging and not intended to be a production error message.
+// it also allows FieldValidationError to be used as an Error interface
+func (e FieldValidationError) Error() string {
+	return fmt.Sprintf(validationErrMsg, e.Field, e.ErrorTag)
+}
+
 // StructValidationErrors is a struct of errors for struct fields ( Excluding fields of type struct )
 // NOTE: if a field within a struct is a struct it's errors will not be contained within the current
 // StructValidationErrors but rather a new StructValidationErrors is created for each struct resulting in
@@ -27,6 +36,19 @@ type StructValidationErrors struct {
 	Errors map[string]*FieldValidationError
 }
 
+// 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 := ""
+
+	for _, err := range e.Errors {
+		s += fmt.Sprintf(validationErrMsg, err.Field, err.ErrorTag)
+	}
+
+	return s
+}
+
 // ValidationFunc that accepts the value of a field and parameter for use in validation (parameter not always used or needed)
 type ValidationFunc func(v interface{}, param string) bool
 
@@ -43,7 +65,7 @@ type Validator struct {
 
 // var bakedInValidators = map[string]ValidationFunc{}
 
-var internalValidator = NewValidator("validate", bakedInValidators)
+var internalValidator = NewValidator(defaultTagName, bakedInValidators)
 
 // 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.
@@ -237,6 +259,7 @@ func (v *Validator) validateFieldByNameAndTag(f interface{}, name string, tag st
 			log.Fatalf("Invalid validation tag on field %s", name)
 		}
 
+		// OK to continue because we checked it's existance before getting into this loop
 		if key == omitempty {
 			continue
 		}
diff --git a/validator_test.go b/validator_test.go
index 5a4a344..1010506 100644
--- a/validator_test.go
+++ b/validator_test.go
@@ -35,6 +35,7 @@ func TestValidateStruct(t *testing.T) {
 		for _, j := range i.Errors {
 
 			fmt.Printf("Error Field:%s Error Tag:%s\n", j.Field, j.ErrorTag)
+			fmt.Println(j.Error())
 		}
 	}