dip/vendor/github.com/labstack/echo/v4/bind.go
Paul Lecuq fa74f7ad4c
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updated dependencies
2024-04-28 13:08:41 +02:00

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Go

// SPDX-License-Identifier: MIT
// SPDX-FileCopyrightText: © 2015 LabStack LLC and Echo contributors
package echo
import (
"encoding"
"encoding/xml"
"errors"
"fmt"
"net/http"
"reflect"
"strconv"
"strings"
)
// Binder is the interface that wraps the Bind method.
type Binder interface {
Bind(i interface{}, c Context) error
}
// DefaultBinder is the default implementation of the Binder interface.
type DefaultBinder struct{}
// BindUnmarshaler is the interface used to wrap the UnmarshalParam method.
// Types that don't implement this, but do implement encoding.TextUnmarshaler
// will use that interface instead.
type BindUnmarshaler interface {
// UnmarshalParam decodes and assigns a value from an form or query param.
UnmarshalParam(param string) error
}
// bindMultipleUnmarshaler is used by binder to unmarshal multiple values from request at once to
// type implementing this interface. For example request could have multiple query fields `?a=1&a=2&b=test` in that case
// for `a` following slice `["1", "2"] will be passed to unmarshaller.
type bindMultipleUnmarshaler interface {
UnmarshalParams(params []string) error
}
// BindPathParams binds path params to bindable object
func (b *DefaultBinder) BindPathParams(c Context, i interface{}) error {
names := c.ParamNames()
values := c.ParamValues()
params := map[string][]string{}
for i, name := range names {
params[name] = []string{values[i]}
}
if err := b.bindData(i, params, "param"); err != nil {
return NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
}
return nil
}
// BindQueryParams binds query params to bindable object
func (b *DefaultBinder) BindQueryParams(c Context, i interface{}) error {
if err := b.bindData(i, c.QueryParams(), "query"); err != nil {
return NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
}
return nil
}
// BindBody binds request body contents to bindable object
// NB: then binding forms take note that this implementation uses standard library form parsing
// which parses form data from BOTH URL and BODY if content type is not MIMEMultipartForm
// See non-MIMEMultipartForm: https://golang.org/pkg/net/http/#Request.ParseForm
// See MIMEMultipartForm: https://golang.org/pkg/net/http/#Request.ParseMultipartForm
func (b *DefaultBinder) BindBody(c Context, i interface{}) (err error) {
req := c.Request()
if req.ContentLength == 0 {
return
}
ctype := req.Header.Get(HeaderContentType)
switch {
case strings.HasPrefix(ctype, MIMEApplicationJSON):
if err = c.Echo().JSONSerializer.Deserialize(c, i); err != nil {
switch err.(type) {
case *HTTPError:
return err
default:
return NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
}
}
case strings.HasPrefix(ctype, MIMEApplicationXML), strings.HasPrefix(ctype, MIMETextXML):
if err = xml.NewDecoder(req.Body).Decode(i); err != nil {
if ute, ok := err.(*xml.UnsupportedTypeError); ok {
return NewHTTPError(http.StatusBadRequest, fmt.Sprintf("Unsupported type error: type=%v, error=%v", ute.Type, ute.Error())).SetInternal(err)
} else if se, ok := err.(*xml.SyntaxError); ok {
return NewHTTPError(http.StatusBadRequest, fmt.Sprintf("Syntax error: line=%v, error=%v", se.Line, se.Error())).SetInternal(err)
}
return NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
}
case strings.HasPrefix(ctype, MIMEApplicationForm), strings.HasPrefix(ctype, MIMEMultipartForm):
params, err := c.FormParams()
if err != nil {
return NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
}
if err = b.bindData(i, params, "form"); err != nil {
return NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
}
default:
return ErrUnsupportedMediaType
}
return nil
}
// BindHeaders binds HTTP headers to a bindable object
func (b *DefaultBinder) BindHeaders(c Context, i interface{}) error {
if err := b.bindData(i, c.Request().Header, "header"); err != nil {
return NewHTTPError(http.StatusBadRequest, err.Error()).SetInternal(err)
}
return nil
}
// Bind implements the `Binder#Bind` function.
// Binding is done in following order: 1) path params; 2) query params; 3) request body. Each step COULD override previous
// step binded values. For single source binding use their own methods BindBody, BindQueryParams, BindPathParams.
func (b *DefaultBinder) Bind(i interface{}, c Context) (err error) {
if err := b.BindPathParams(c, i); err != nil {
return err
}
// Only bind query parameters for GET/DELETE/HEAD to avoid unexpected behavior with destination struct binding from body.
// For example a request URL `&id=1&lang=en` with body `{"id":100,"lang":"de"}` would lead to precedence issues.
// The HTTP method check restores pre-v4.1.11 behavior to avoid these problems (see issue #1670)
method := c.Request().Method
if method == http.MethodGet || method == http.MethodDelete || method == http.MethodHead {
if err = b.BindQueryParams(c, i); err != nil {
return err
}
}
return b.BindBody(c, i)
}
// bindData will bind data ONLY fields in destination struct that have EXPLICIT tag
func (b *DefaultBinder) bindData(destination interface{}, data map[string][]string, tag string) error {
if destination == nil || len(data) == 0 {
return nil
}
typ := reflect.TypeOf(destination).Elem()
val := reflect.ValueOf(destination).Elem()
// Support binding to limited Map destinations:
// - map[string][]string,
// - map[string]string <-- (binds first value from data slice)
// - map[string]interface{}
// You are better off binding to struct but there are user who want this map feature. Source of data for these cases are:
// params,query,header,form as these sources produce string values, most of the time slice of strings, actually.
if typ.Kind() == reflect.Map && typ.Key().Kind() == reflect.String {
k := typ.Elem().Kind()
isElemInterface := k == reflect.Interface
isElemString := k == reflect.String
isElemSliceOfStrings := k == reflect.Slice && typ.Elem().Elem().Kind() == reflect.String
if !(isElemSliceOfStrings || isElemString || isElemInterface) {
return nil
}
if val.IsNil() {
val.Set(reflect.MakeMap(typ))
}
for k, v := range data {
if isElemString {
val.SetMapIndex(reflect.ValueOf(k), reflect.ValueOf(v[0]))
} else {
val.SetMapIndex(reflect.ValueOf(k), reflect.ValueOf(v))
}
}
return nil
}
// !struct
if typ.Kind() != reflect.Struct {
if tag == "param" || tag == "query" || tag == "header" {
// incompatible type, data is probably to be found in the body
return nil
}
return errors.New("binding element must be a struct")
}
for i := 0; i < typ.NumField(); i++ {
typeField := typ.Field(i)
structField := val.Field(i)
if typeField.Anonymous {
if structField.Kind() == reflect.Ptr {
structField = structField.Elem()
}
}
if !structField.CanSet() {
continue
}
structFieldKind := structField.Kind()
inputFieldName := typeField.Tag.Get(tag)
if typeField.Anonymous && structFieldKind == reflect.Struct && inputFieldName != "" {
// if anonymous struct with query/param/form tags, report an error
return errors.New("query/param/form tags are not allowed with anonymous struct field")
}
if inputFieldName == "" {
// If tag is nil, we inspect if the field is a not BindUnmarshaler struct and try to bind data into it (might contains fields with tags).
// structs that implement BindUnmarshaler are bound only when they have explicit tag
if _, ok := structField.Addr().Interface().(BindUnmarshaler); !ok && structFieldKind == reflect.Struct {
if err := b.bindData(structField.Addr().Interface(), data, tag); err != nil {
return err
}
}
// does not have explicit tag and is not an ordinary struct - so move to next field
continue
}
inputValue, exists := data[inputFieldName]
if !exists {
// Go json.Unmarshal supports case insensitive binding. However the
// url params are bound case sensitive which is inconsistent. To
// fix this we must check all of the map values in a
// case-insensitive search.
for k, v := range data {
if strings.EqualFold(k, inputFieldName) {
inputValue = v
exists = true
break
}
}
}
if !exists {
continue
}
// NOTE: algorithm here is not particularly sophisticated. It probably does not work with absurd types like `**[]*int`
// but it is smart enough to handle niche cases like `*int`,`*[]string`,`[]*int` .
// try unmarshalling first, in case we're dealing with an alias to an array type
if ok, err := unmarshalInputsToField(typeField.Type.Kind(), inputValue, structField); ok {
if err != nil {
return err
}
continue
}
if ok, err := unmarshalInputToField(typeField.Type.Kind(), inputValue[0], structField); ok {
if err != nil {
return err
}
continue
}
// we could be dealing with pointer to slice `*[]string` so dereference it. There are wierd OpenAPI generators
// that could create struct fields like that.
if structFieldKind == reflect.Pointer {
structFieldKind = structField.Elem().Kind()
structField = structField.Elem()
}
if structFieldKind == reflect.Slice {
sliceOf := structField.Type().Elem().Kind()
numElems := len(inputValue)
slice := reflect.MakeSlice(structField.Type(), numElems, numElems)
for j := 0; j < numElems; j++ {
if err := setWithProperType(sliceOf, inputValue[j], slice.Index(j)); err != nil {
return err
}
}
structField.Set(slice)
continue
}
if err := setWithProperType(structFieldKind, inputValue[0], structField); err != nil {
return err
}
}
return nil
}
func setWithProperType(valueKind reflect.Kind, val string, structField reflect.Value) error {
// But also call it here, in case we're dealing with an array of BindUnmarshalers
if ok, err := unmarshalInputToField(valueKind, val, structField); ok {
return err
}
switch valueKind {
case reflect.Ptr:
return setWithProperType(structField.Elem().Kind(), val, structField.Elem())
case reflect.Int:
return setIntField(val, 0, structField)
case reflect.Int8:
return setIntField(val, 8, structField)
case reflect.Int16:
return setIntField(val, 16, structField)
case reflect.Int32:
return setIntField(val, 32, structField)
case reflect.Int64:
return setIntField(val, 64, structField)
case reflect.Uint:
return setUintField(val, 0, structField)
case reflect.Uint8:
return setUintField(val, 8, structField)
case reflect.Uint16:
return setUintField(val, 16, structField)
case reflect.Uint32:
return setUintField(val, 32, structField)
case reflect.Uint64:
return setUintField(val, 64, structField)
case reflect.Bool:
return setBoolField(val, structField)
case reflect.Float32:
return setFloatField(val, 32, structField)
case reflect.Float64:
return setFloatField(val, 64, structField)
case reflect.String:
structField.SetString(val)
default:
return errors.New("unknown type")
}
return nil
}
func unmarshalInputsToField(valueKind reflect.Kind, values []string, field reflect.Value) (bool, error) {
if valueKind == reflect.Ptr {
if field.IsNil() {
field.Set(reflect.New(field.Type().Elem()))
}
field = field.Elem()
}
fieldIValue := field.Addr().Interface()
unmarshaler, ok := fieldIValue.(bindMultipleUnmarshaler)
if !ok {
return false, nil
}
return true, unmarshaler.UnmarshalParams(values)
}
func unmarshalInputToField(valueKind reflect.Kind, val string, field reflect.Value) (bool, error) {
if valueKind == reflect.Ptr {
if field.IsNil() {
field.Set(reflect.New(field.Type().Elem()))
}
field = field.Elem()
}
fieldIValue := field.Addr().Interface()
switch unmarshaler := fieldIValue.(type) {
case BindUnmarshaler:
return true, unmarshaler.UnmarshalParam(val)
case encoding.TextUnmarshaler:
return true, unmarshaler.UnmarshalText([]byte(val))
}
return false, nil
}
func setIntField(value string, bitSize int, field reflect.Value) error {
if value == "" {
value = "0"
}
intVal, err := strconv.ParseInt(value, 10, bitSize)
if err == nil {
field.SetInt(intVal)
}
return err
}
func setUintField(value string, bitSize int, field reflect.Value) error {
if value == "" {
value = "0"
}
uintVal, err := strconv.ParseUint(value, 10, bitSize)
if err == nil {
field.SetUint(uintVal)
}
return err
}
func setBoolField(value string, field reflect.Value) error {
if value == "" {
value = "false"
}
boolVal, err := strconv.ParseBool(value)
if err == nil {
field.SetBool(boolVal)
}
return err
}
func setFloatField(value string, bitSize int, field reflect.Value) error {
if value == "" {
value = "0.0"
}
floatVal, err := strconv.ParseFloat(value, bitSize)
if err == nil {
field.SetFloat(floatVal)
}
return err
}