Feat: support validate struct without struct tag (#934)

Author: leoliang1997

_examples/struct-map-rules-validation/main.go

@@ -0,0 +1,92 @@
+package main
+
+import (
+	"fmt"
+	"github.com/go-playground/validator/v10"
+)
+
+type Data struct {
+	Name    string
+	Email   string
+	Details *Details
+}
+
+type Details struct {
+	FamilyMembers *FamilyMembers
+	Salary        string
+}
+
+type FamilyMembers struct {
+	FatherName string
+	MotherName string
+}
+
+type Data2 struct {
+	Name string
+	Age  uint32
+}
+
+var validate = validator.New()
+
+func main() {
+	validateStruct()
+	// output
+	// Key: 'Data2.Name' Error:Field validation for 'Name' failed on the 'min' tag
+	// Key: 'Data2.Age' Error:Field validation for 'Age' failed on the 'max' tag
+
+	validateStructNested()
+	// output
+	// Key: 'Data.Name' Error:Field validation for 'Name' failed on the 'max' tag
+	// Key: 'Data.Details.FamilyMembers' Error:Field validation for 'FamilyMembers' failed on the 'required' tag
+}
+
+func validateStruct() {
+	data := Data2{
+		Name: "leo",
+		Age:  1000,
+	}
+
+	rules := map[string]string{
+		"Name": "min=4,max=6",
+		"Age":  "min=4,max=6",
+	}
+
+	validate.RegisterStructValidationMapRules(rules, Data2{})
+
+	err := validate.Struct(data)
+	fmt.Println(err)
+	fmt.Println()
+}
+
+func validateStructNested() {
+	data := Data{
+		Name:  "11sdfddd111",
+		Email: "[email protected]",
+		Details: &Details{
+			Salary: "1000",
+		},
+	}
+
+	rules1 := map[string]string{
+		"Name":    "min=4,max=6",
+		"Email":   "required,email",
+		"Details": "required",
+	}
+
+	rules2 := map[string]string{
+		"Salary":        "number",
+		"FamilyMembers": "required",
+	}
+
+	rules3 := map[string]string{
+		"FatherName": "required,min=4,max=32",
+		"MotherName": "required,min=4,max=32",
+	}
+
+	validate.RegisterStructValidationMapRules(rules1, Data{})
+	validate.RegisterStructValidationMapRules(rules2, Details{})
+	validate.RegisterStructValidationMapRules(rules3, FamilyMembers{})
+	err := validate.Struct(data)
+
+	fmt.Println(err)
+}

cache.go

@@ -114,12 +114,13 @@ func (v *Validate) extractStructCache(current reflect.Value, sName string) *cStr
 	cs = &cStruct{name: sName, fields: make([]*cField, 0), fn: v.structLevelFuncs[typ]}
 
 	numFields := current.NumField()
+	rules := v.rules[typ]
 
 	var ctag *cTag
 	var fld reflect.StructField
 	var tag string
 	var customName string
-
+	
 	for i := 0; i < numFields; i++ {
 
 		fld = typ.Field(i)
@@ -128,7 +129,11 @@ func (v *Validate) extractStructCache(current reflect.Value, sName string) *cStr
 			continue
 		}
 
-		tag = fld.Tag.Get(v.tagName)
+		if rtag, ok := rules[fld.Name]; ok {
+			tag = rtag
+		} else {
+			tag = fld.Tag.Get(v.tagName)
+		}
 
 		if tag == skipValidationTag {
 			continue

validator_instance.go

@@ -86,6 +86,7 @@ type Validate struct {
 	aliases          map[string]string
 	validations      map[string]internalValidationFuncWrapper
 	transTagFunc     map[ut.Translator]map[string]TranslationFunc // map[<locale>]map[<tag>]TranslationFunc
+	rules            map[reflect.Type]map[string]string
 	tagCache         *tagCache
 	structCache      *structCache
 }
@@ -283,6 +284,33 @@ func (v *Validate) RegisterStructValidationCtx(fn StructLevelFuncCtx, types ...i
 	}
 }
 
+// RegisterStructValidationMapRules registers validate map rules
+//
+// NOTE: this method is not thread-safe it is intended that these all be registered prior to any validation
+func (v *Validate) RegisterStructValidationMapRules(rules map[string]string, types ...interface{}) {
+	if v.rules == nil {
+		v.rules = make(map[reflect.Type]map[string]string)
+	}
+
+	deepCopyRules := make(map[string]string)
+	for i, rule := range rules {
+		deepCopyRules[i] = rule
+	}
+
+	for _, t := range types {
+		typ := reflect.TypeOf(t)
+
+		if typ.Kind() == reflect.Ptr {
+			typ = typ.Elem()
+		}
+
+		if typ.Kind() != reflect.Struct {
+			continue
+		}
+		v.rules[typ] = deepCopyRules
+	}
+}
+
 // RegisterCustomTypeFunc registers a CustomTypeFunc against a number of types
 //
 // NOTE: this method is not thread-safe it is intended that these all be registered prior to any validation