Files
gf/util/gconv/gconv_struct.go

663 lines
21 KiB
Go

// Copyright GoFrame Author(https://goframe.org). All Rights Reserved.
//
// This Source Code Form is subject to the terms of the MIT License.
// If a copy of the MIT was not distributed with this file,
// You can obtain one at https://github.com/gogf/gf.
package gconv
import (
"reflect"
"strings"
"github.com/gogf/gf/v2/errors/gcode"
"github.com/gogf/gf/v2/errors/gerror"
"github.com/gogf/gf/v2/internal/empty"
"github.com/gogf/gf/v2/internal/json"
"github.com/gogf/gf/v2/internal/utils"
"github.com/gogf/gf/v2/util/gtag"
)
// Struct maps the params key-value pairs to the corresponding struct object's attributes.
// The third parameter `mapping` is unnecessary, indicating the mapping rules between the
// custom key name and the attribute name(case-sensitive).
//
// Note:
// 1. The `params` can be any type of map/struct, usually a map.
// 2. The `pointer` should be type of *struct/**struct, which is a pointer to struct object
// or struct pointer.
// 3. Only the public attributes of struct object can be mapped.
// 4. If `params` is a map, the key of the map `params` can be lowercase.
// It will automatically convert the first letter of the key to uppercase
// in mapping procedure to do the matching.
// It ignores the map key, if it does not match.
func Struct(params interface{}, pointer interface{}, paramKeyToAttrMap ...map[string]string) (err error) {
return Scan(params, pointer, paramKeyToAttrMap...)
}
// StructTag acts as Struct but also with support for priority tag feature, which retrieves the
// specified tags for `params` key-value items to struct attribute names mapping.
// The parameter `priorityTag` supports multiple tags that can be joined with char ','.
func StructTag(params interface{}, pointer interface{}, priorityTag string) (err error) {
return doStruct(params, pointer, nil, priorityTag)
}
// doStruct is the core internal converting function for any data to struct.
func doStruct(
params interface{}, pointer interface{}, paramKeyToAttrMap map[string]string, priorityTag string,
) (err error) {
if params == nil {
// If `params` is nil, no conversion.
return nil
}
if pointer == nil {
return gerror.NewCode(gcode.CodeInvalidParameter, "object pointer cannot be nil")
}
// JSON content converting.
ok, err := doConvertWithJsonCheck(params, pointer)
if err != nil {
return err
}
if ok {
return nil
}
defer func() {
// Catch the panic, especially the reflection operation panics.
if exception := recover(); exception != nil {
if v, ok := exception.(error); ok && gerror.HasStack(v) {
err = v
} else {
err = gerror.NewCodeSkipf(gcode.CodeInternalPanic, 1, "%+v", exception)
}
}
}()
var (
paramsReflectValue reflect.Value
paramsInterface interface{} // DO NOT use `params` directly as it might be type `reflect.Value`
pointerReflectValue reflect.Value
pointerReflectKind reflect.Kind
pointerElemReflectValue reflect.Value // The pointed element.
)
if v, ok := params.(reflect.Value); ok {
paramsReflectValue = v
} else {
paramsReflectValue = reflect.ValueOf(params)
}
paramsInterface = paramsReflectValue.Interface()
if v, ok := pointer.(reflect.Value); ok {
pointerReflectValue = v
pointerElemReflectValue = v
} else {
pointerReflectValue = reflect.ValueOf(pointer)
pointerReflectKind = pointerReflectValue.Kind()
if pointerReflectKind != reflect.Ptr {
return gerror.NewCodef(
gcode.CodeInvalidParameter,
"destination pointer should be type of '*struct', but got '%v'",
pointerReflectKind,
)
}
// Using IsNil on reflect.Ptr variable is OK.
if !pointerReflectValue.IsValid() || pointerReflectValue.IsNil() {
return gerror.NewCode(
gcode.CodeInvalidParameter,
"destination pointer cannot be nil",
)
}
pointerElemReflectValue = pointerReflectValue.Elem()
}
// If `params` and `pointer` are the same type, the do directly assignment.
// For performance enhancement purpose.
if ok = doConvertWithTypeCheck(paramsReflectValue, pointerElemReflectValue); ok {
return nil
}
// custom convert.
if ok, err = callCustomConverter(paramsReflectValue, pointerReflectValue); ok {
return err
}
// Normal unmarshalling interfaces checks.
if ok, err = bindVarToReflectValueWithInterfaceCheck(pointerReflectValue, paramsInterface); ok {
return err
}
// It automatically creates struct object if necessary.
// For example, if `pointer` is **User, then `elem` is *User, which is a pointer to User.
if pointerElemReflectValue.Kind() == reflect.Ptr {
if !pointerElemReflectValue.IsValid() || pointerElemReflectValue.IsNil() {
e := reflect.New(pointerElemReflectValue.Type().Elem())
pointerElemReflectValue.Set(e)
defer func() {
if err != nil {
// If it is converted failed, it reset the `pointer` to nil.
pointerReflectValue.Elem().Set(reflect.Zero(pointerReflectValue.Type().Elem()))
}
}()
}
// if v, ok := pointerElemReflectValue.Interface().(iUnmarshalValue); ok {
// return v.UnmarshalValue(params)
// }
// Note that it's `pointerElemReflectValue` here not `pointerReflectValue`.
if ok, err = bindVarToReflectValueWithInterfaceCheck(pointerElemReflectValue, paramsInterface); ok {
return err
}
// Retrieve its element, may be struct at last.
pointerElemReflectValue = pointerElemReflectValue.Elem()
}
// paramsMap is the map[string]interface{} type variable for params.
// DO NOT use MapDeep here.
paramsMap := doMapConvert(paramsInterface, recursiveTypeAuto, true)
if paramsMap == nil {
return gerror.NewCodef(
gcode.CodeInvalidParameter,
`convert params from "%#v" to "map[string]interface{}" failed`,
params,
)
}
// Nothing to be done as the parameters are empty.
if len(paramsMap) == 0 {
return nil
}
// Holds the info for subsequent converting.
type toBeConvertedFieldInfo struct {
Value any // Found value by tag name or field name from input.
FieldIndex int // The associated reflection field index.
FieldOrTagName string // Field name or tag name for field tag by priority tags.
}
var (
priorityTagArray []string
elemFieldName string
elemFieldType reflect.StructField
elemFieldValue reflect.Value
elemType = pointerElemReflectValue.Type()
toBeConvertedFieldNameToInfoMap = map[string]toBeConvertedFieldInfo{} // key=elemFieldName
)
if priorityTag != "" {
priorityTagArray = append(utils.SplitAndTrim(priorityTag, ","), gtag.StructTagPriority...)
} else {
priorityTagArray = gtag.StructTagPriority
}
for i := 0; i < pointerElemReflectValue.NumField(); i++ {
elemFieldType = elemType.Field(i)
elemFieldName = elemFieldType.Name
// Only do converting to public attributes.
if !utils.IsLetterUpper(elemFieldName[0]) {
continue
}
var fieldTagName = getTagNameFromField(elemFieldType, priorityTagArray)
// Maybe it's struct/*struct embedded.
if elemFieldType.Anonymous {
// type Name struct {
// LastName string `json:"lastName"`
// FirstName string `json:"firstName"`
// }
//
// type User struct {
// Name `json:"name"`
// // ...
// }
//
// It is only recorded if the name has a fieldTag
if fieldTagName != "" {
toBeConvertedFieldNameToInfoMap[elemFieldName] = toBeConvertedFieldInfo{
FieldIndex: elemFieldType.Index[0],
FieldOrTagName: fieldTagName,
}
}
elemFieldValue = pointerElemReflectValue.Field(i)
// Ignore the interface attribute if it's nil.
if elemFieldValue.Kind() == reflect.Interface {
elemFieldValue = elemFieldValue.Elem()
if !elemFieldValue.IsValid() {
continue
}
}
if err = doStruct(paramsMap, elemFieldValue, paramKeyToAttrMap, priorityTag); err != nil {
return err
}
} else {
// Use the native elemFieldName name as the fieldTag
if fieldTagName == "" {
fieldTagName = elemFieldName
}
toBeConvertedFieldNameToInfoMap[elemFieldName] = toBeConvertedFieldInfo{
FieldIndex: elemFieldType.Index[0],
FieldOrTagName: fieldTagName,
}
}
}
// Nothing to be converted.
if len(toBeConvertedFieldNameToInfoMap) == 0 {
return nil
}
// Search the parameter value for the field.
var paramsValue any
for fieldName, fieldInfo := range toBeConvertedFieldNameToInfoMap {
if paramsValue, ok = paramsMap[fieldInfo.FieldOrTagName]; ok {
fieldInfo.Value = paramsValue
toBeConvertedFieldNameToInfoMap[fieldName] = fieldInfo
}
}
// Firstly, search according to custom mapping rules.
// If a possible direct assignment is found, reduce the number of subsequent map searches.
var fieldInfo toBeConvertedFieldInfo
for paramKey, fieldName := range paramKeyToAttrMap {
// Prevent setting of non-existent fields
fieldInfo, ok = toBeConvertedFieldNameToInfoMap[fieldName]
if ok {
// Prevent non-existent values from being set.
if paramsValue, ok = paramsMap[paramKey]; ok {
fieldInfo.Value = paramsValue
toBeConvertedFieldNameToInfoMap[fieldName] = fieldInfo
}
}
}
var (
paramKey string
paramValue any
fieldName string
// Indicates that those values have been used and cannot be reused.
usedParamsKeyOrTagNameMap = map[string]struct{}{}
)
for fieldName, fieldInfo = range toBeConvertedFieldNameToInfoMap {
// If it is not empty, the tag or elemFieldName name matches
if fieldInfo.Value != nil {
if err = bindVarToStructAttrWithFieldIndex(
pointerElemReflectValue, fieldName, fieldInfo.FieldIndex, fieldInfo.Value, paramKeyToAttrMap,
); err != nil {
return err
}
usedParamsKeyOrTagNameMap[fieldInfo.FieldOrTagName] = struct{}{}
continue
}
// If value is nil, a fuzzy match is used for search the key and value for converting.
paramKey, paramValue = fuzzyMatchingFieldName(fieldName, paramsMap, usedParamsKeyOrTagNameMap)
if paramValue != nil {
if err = bindVarToStructAttrWithFieldIndex(
pointerElemReflectValue, fieldName, fieldInfo.FieldIndex, paramValue, paramKeyToAttrMap,
); err != nil {
return err
}
usedParamsKeyOrTagNameMap[paramKey] = struct{}{}
}
}
return nil
}
func getTagNameFromField(field reflect.StructField, priorityTags []string) string {
for _, tag := range priorityTags {
value, ok := field.Tag.Lookup(tag)
if ok {
// If there's something else in the tag string,
// it uses the first part which is split using char ','.
// Example:
// orm:"id, priority"
// orm:"name, with:uid=id"
array := strings.Split(value, ",")
// json:",omitempty"
trimmedTagName := strings.TrimSpace(array[0])
return trimmedTagName
}
}
return ""
}
// fuzzy matching rule:
// to match field name and param key in case-insensitive and without symbols.
func fuzzyMatchingFieldName(
fieldName string,
paramsMap map[string]any,
usedParamsKeyMap map[string]struct{},
) (string, any) {
fieldName = utils.RemoveSymbols(fieldName)
for paramKey, paramValue := range paramsMap {
if _, ok := usedParamsKeyMap[paramKey]; ok {
continue
}
removeParamKeyUnderline := utils.RemoveSymbols(paramKey)
if strings.EqualFold(fieldName, removeParamKeyUnderline) {
return paramKey, paramValue
}
}
return "", nil
}
// bindVarToStructAttrWithFieldIndex sets value to struct object attribute by name.
func bindVarToStructAttrWithFieldIndex(
structReflectValue reflect.Value, attrName string,
fieldIndex int, value interface{}, paramKeyToAttrMap map[string]string,
) (err error) {
structFieldValue := structReflectValue.Field(fieldIndex)
if !structFieldValue.IsValid() {
return nil
}
// CanSet checks whether attribute is public accessible.
if !structFieldValue.CanSet() {
return nil
}
defer func() {
if exception := recover(); exception != nil {
if err = bindVarToReflectValue(structFieldValue, value, paramKeyToAttrMap); err != nil {
err = gerror.Wrapf(err, `error binding value to attribute "%s"`, attrName)
}
}
}()
// Directly converting.
if empty.IsNil(value) {
structFieldValue.Set(reflect.Zero(structFieldValue.Type()))
} else {
// Try to call custom converter.
// Issue: https://github.com/gogf/gf/issues/3099
var (
customConverterInput reflect.Value
ok bool
)
if customConverterInput, ok = value.(reflect.Value); !ok {
customConverterInput = reflect.ValueOf(value)
}
if ok, err = callCustomConverter(customConverterInput, structFieldValue); ok || err != nil {
return
}
// Special handling for certain types:
// - Overwrite the default type converting logic of stdlib for time.Time/*time.Time.
var structFieldTypeName = structFieldValue.Type().String()
switch structFieldTypeName {
case "time.Time", "*time.Time":
doConvertWithReflectValueSet(structFieldValue, doConvertInput{
FromValue: value,
ToTypeName: structFieldTypeName,
ReferValue: structFieldValue,
})
return
// Hold the time zone consistent in recursive
// Issue: https://github.com/gogf/gf/issues/2980
case "*gtime.Time", "gtime.Time":
doConvertWithReflectValueSet(structFieldValue, doConvertInput{
FromValue: value,
ToTypeName: structFieldTypeName,
ReferValue: structFieldValue,
})
return
}
// Common interface check.
if ok, err = bindVarToReflectValueWithInterfaceCheck(structFieldValue, value); ok {
return err
}
// Default converting.
doConvertWithReflectValueSet(structFieldValue, doConvertInput{
FromValue: value,
ToTypeName: structFieldTypeName,
ReferValue: structFieldValue,
})
}
return nil
}
// bindVarToReflectValueWithInterfaceCheck does bind using common interfaces checks.
func bindVarToReflectValueWithInterfaceCheck(reflectValue reflect.Value, value interface{}) (bool, error) {
var pointer interface{}
if reflectValue.Kind() != reflect.Ptr && reflectValue.CanAddr() {
reflectValueAddr := reflectValue.Addr()
if reflectValueAddr.IsNil() || !reflectValueAddr.IsValid() {
return false, nil
}
// Not a pointer, but can token address, that makes it can be unmarshalled.
pointer = reflectValue.Addr().Interface()
} else {
if reflectValue.IsNil() || !reflectValue.IsValid() {
return false, nil
}
pointer = reflectValue.Interface()
}
// UnmarshalValue.
if v, ok := pointer.(iUnmarshalValue); ok {
return ok, v.UnmarshalValue(value)
}
// UnmarshalText.
if v, ok := pointer.(iUnmarshalText); ok {
var valueBytes []byte
if b, ok := value.([]byte); ok {
valueBytes = b
} else if s, ok := value.(string); ok {
valueBytes = []byte(s)
} else if f, ok := value.(iString); ok {
valueBytes = []byte(f.String())
}
if len(valueBytes) > 0 {
return ok, v.UnmarshalText(valueBytes)
}
}
// UnmarshalJSON.
if v, ok := pointer.(iUnmarshalJSON); ok {
var valueBytes []byte
if b, ok := value.([]byte); ok {
valueBytes = b
} else if s, ok := value.(string); ok {
valueBytes = []byte(s)
} else if f, ok := value.(iString); ok {
valueBytes = []byte(f.String())
}
if len(valueBytes) > 0 {
// If it is not a valid JSON string, it then adds char `"` on its both sides to make it is.
if !json.Valid(valueBytes) {
newValueBytes := make([]byte, len(valueBytes)+2)
newValueBytes[0] = '"'
newValueBytes[len(newValueBytes)-1] = '"'
copy(newValueBytes[1:], valueBytes)
valueBytes = newValueBytes
}
return ok, v.UnmarshalJSON(valueBytes)
}
}
if v, ok := pointer.(iSet); ok {
v.Set(value)
return ok, nil
}
return false, nil
}
// bindVarToReflectValue sets `value` to reflect value object `structFieldValue`.
func bindVarToReflectValue(
structFieldValue reflect.Value, value interface{}, paramKeyToAttrMap map[string]string,
) (err error) {
// JSON content converting.
ok, err := doConvertWithJsonCheck(value, structFieldValue)
if err != nil {
return err
}
if ok {
return nil
}
kind := structFieldValue.Kind()
// Converting using `Set` interface implements, for some types.
switch kind {
case reflect.Slice, reflect.Array, reflect.Ptr, reflect.Interface:
if !structFieldValue.IsNil() {
if v, ok := structFieldValue.Interface().(iSet); ok {
v.Set(value)
return nil
}
}
}
// Converting using reflection by kind.
switch kind {
case reflect.Map:
return doMapToMap(value, structFieldValue, paramKeyToAttrMap)
case reflect.Struct:
// Recursively converting for struct attribute.
if err = doStruct(value, structFieldValue, nil, ""); err != nil {
// Note there's reflect conversion mechanism here.
structFieldValue.Set(reflect.ValueOf(value).Convert(structFieldValue.Type()))
}
// Note that the slice element might be type of struct,
// so it uses Struct function doing the converting internally.
case reflect.Slice, reflect.Array:
var (
reflectArray reflect.Value
reflectValue = reflect.ValueOf(value)
)
if reflectValue.Kind() == reflect.Slice || reflectValue.Kind() == reflect.Array {
reflectArray = reflect.MakeSlice(structFieldValue.Type(), reflectValue.Len(), reflectValue.Len())
if reflectValue.Len() > 0 {
var (
elemType = reflectArray.Index(0).Type()
elemTypeName string
converted bool
)
for i := 0; i < reflectValue.Len(); i++ {
converted = false
elemTypeName = elemType.Name()
if elemTypeName == "" {
elemTypeName = elemType.String()
}
var elem reflect.Value
if elemType.Kind() == reflect.Ptr {
elem = reflect.New(elemType.Elem()).Elem()
} else {
elem = reflect.New(elemType).Elem()
}
if elem.Kind() == reflect.Struct {
if err = doStruct(reflectValue.Index(i).Interface(), elem, nil, ""); err == nil {
converted = true
}
}
if !converted {
doConvertWithReflectValueSet(elem, doConvertInput{
FromValue: reflectValue.Index(i).Interface(),
ToTypeName: elemTypeName,
ReferValue: elem,
})
}
if elemType.Kind() == reflect.Ptr {
// Before it sets the `elem` to array, do pointer converting if necessary.
elem = elem.Addr()
}
reflectArray.Index(i).Set(elem)
}
}
} else {
var (
elem reflect.Value
elemType = structFieldValue.Type().Elem()
elemTypeName = elemType.Name()
converted bool
)
switch reflectValue.Kind() {
case reflect.String:
// Value is empty string.
if reflectValue.IsZero() {
var elemKind = elemType.Kind()
// Try to find the original type kind of the slice element.
if elemKind == reflect.Ptr {
elemKind = elemType.Elem().Kind()
}
switch elemKind {
case reflect.String:
// Empty string cannot be assigned to string slice.
return nil
}
}
}
if elemTypeName == "" {
elemTypeName = elemType.String()
}
if elemType.Kind() == reflect.Ptr {
elem = reflect.New(elemType.Elem()).Elem()
} else {
elem = reflect.New(elemType).Elem()
}
if elem.Kind() == reflect.Struct {
if err = doStruct(value, elem, nil, ""); err == nil {
converted = true
}
}
if !converted {
doConvertWithReflectValueSet(elem, doConvertInput{
FromValue: value,
ToTypeName: elemTypeName,
ReferValue: elem,
})
}
if elemType.Kind() == reflect.Ptr {
// Before it sets the `elem` to array, do pointer converting if necessary.
elem = elem.Addr()
}
reflectArray = reflect.MakeSlice(structFieldValue.Type(), 1, 1)
reflectArray.Index(0).Set(elem)
}
structFieldValue.Set(reflectArray)
case reflect.Ptr:
if structFieldValue.IsNil() || structFieldValue.IsZero() {
// Nil or empty pointer, it creates a new one.
item := reflect.New(structFieldValue.Type().Elem())
if ok, err = bindVarToReflectValueWithInterfaceCheck(item, value); ok {
structFieldValue.Set(item)
return err
}
elem := item.Elem()
if err = bindVarToReflectValue(elem, value, paramKeyToAttrMap); err == nil {
structFieldValue.Set(elem.Addr())
}
} else {
// Not empty pointer, it assigns values to it.
return bindVarToReflectValue(structFieldValue.Elem(), value, paramKeyToAttrMap)
}
// It mainly and specially handles the interface of nil value.
case reflect.Interface:
if value == nil {
// Specially.
structFieldValue.Set(reflect.ValueOf((*interface{})(nil)))
} else {
// Note there's reflect conversion mechanism here.
structFieldValue.Set(reflect.ValueOf(value).Convert(structFieldValue.Type()))
}
default:
defer func() {
if exception := recover(); exception != nil {
err = gerror.NewCodef(
gcode.CodeInternalPanic,
`cannot convert value "%+v" to type "%s":%+v`,
value,
structFieldValue.Type().String(),
exception,
)
}
}()
// It here uses reflect converting `value` to type of the attribute and assigns
// the result value to the attribute. It might fail and panic if the usual Go
// conversion rules do not allow conversion.
structFieldValue.Set(reflect.ValueOf(value).Convert(structFieldValue.Type()))
}
return nil
}