Add usage of DecodeCustomTypeFunc within map keys also.

Author: joeybloggs

README.md

@@ -1,7 +1,7 @@
 Package form
 ============
 <img align="right" src="https://raw.githubusercontent.com/go-playground/form/master/logo.jpg">
-![Project status](https://img.shields.io/badge/version-1.2.1-green.svg)
+![Project status](https://img.shields.io/badge/version-1.3.0-green.svg)
 [![Build Status](https://semaphoreci.com/api/v1/joeybloggs/form/branches/master/badge.svg)](https://semaphoreci.com/joeybloggs/form)
 [![Coverage Status](https://coveralls.io/repos/github/go-playground/form/badge.svg?branch=master)](https://coveralls.io/github/go-playground/form?branch=master)
 [![Go Report Card](https://goreportcard.com/badge/github.com/go-playground/form)](https://goreportcard.com/report/github.com/go-playground/form)

decoder.go

@@ -448,6 +448,19 @@ func (d *decoder) getMapKey(key string, current reflect.Value, namespace string)
 
 	v, kind := ExtractType(current)
 
+	if d.d.customTypeFuncs != nil {
+		if cf, ok := d.d.customTypeFuncs[v.Type()]; ok {
+			val, er := cf([]string{key})
+			if er != nil {
+				err = er
+				return
+			}
+
+			v.Set(reflect.ValueOf(val))
+			return
+		}
+	}
+
 	switch kind {
 	case reflect.Interface:
 		v.Set(reflect.ValueOf(key))

form.go

@@ -20,8 +20,8 @@ var (
 	timeType = reflect.TypeOf(time.Time{})
 )
 
-// CustomTypeFunc allows for registering/overriding types to be parsed.
-type CustomTypeFunc func([]string) (interface{}, error)
+// DecodeCustomTypeFunc allows for registering/overriding types to be parsed.
+type DecodeCustomTypeFunc func([]string) (interface{}, error)
 
 // DecodeErrors is a map of errors encountered during form decoding
 type DecodeErrors map[string]error
@@ -62,7 +62,7 @@ type dataMap map[string]*recursiveData
 type Decoder struct {
 	tagName         string
 	structCache     structCacheMap
-	customTypeFuncs map[reflect.Type]CustomTypeFunc
+	customTypeFuncs map[reflect.Type]DecodeCustomTypeFunc
 }
 
 // NewDecoder creates a new decoder instance with sane defaults
@@ -79,12 +79,13 @@ func (d *Decoder) SetTagName(tagName string) {
 	d.tagName = tagName
 }
 
-// RegisterCustomTypeFunc registers a CustomTypeFunc against a number of types
+// RegisterCustomTypeFunc registers a DecodeCustomTypeFunc against a number of types; the function
+// will also be used within the map key section.
 // NOTE: this method is not thread-safe it is intended that these all be registered prior to any parsing
-func (d *Decoder) RegisterCustomTypeFunc(fn CustomTypeFunc, types ...interface{}) {
+func (d *Decoder) RegisterCustomTypeFunc(fn DecodeCustomTypeFunc, types ...interface{}) {
 
 	if d.customTypeFuncs == nil {
-		d.customTypeFuncs = map[reflect.Type]CustomTypeFunc{}
+		d.customTypeFuncs = map[reflect.Type]DecodeCustomTypeFunc{}
 	}
 
 	for _, t := range types {

form_test.go

@@ -518,6 +518,7 @@ func TestStruct(t *testing.T) {
 		BigEnoughNumberedArray     []string
 		IfaceNonNil                interface{}
 		IfaceInvalid               interface{}
+		TimeMapKey                 map[time.Time]string
 	}
 
 	values := url.Values{
@@ -539,6 +540,7 @@ func TestStruct(t *testing.T) {
 		"TooSmallNumberedArray[2]":      []string{"2"},
 		"TooSmallCapOKNumberedArray[2]": []string{"2"},
 		"BigEnoughNumberedArray[2]":     []string{"1"},
+		"TimeMapKey[2016-01-02]":        []string{"time"},
 	}
 
 	var test TestStruct
@@ -604,6 +606,12 @@ func TestStruct(t *testing.T) {
 	Equal(t, test.Time.Equal(tm), true)
 	Equal(t, (*test.TimePtr).Equal(tm), true)
 
+	NotEqual(t, test.TimeMapKey, nil)
+	Equal(t, len(test.TimeMapKey), 1)
+
+	_, ok := test.TimeMapKey[tm]
+	Equal(t, ok, true)
+
 	s := struct {
 		Value     string
 		Ignore    string `form:"-"`
@@ -655,6 +663,7 @@ func TestErrors(t *testing.T) {
 		MapBadBoolKey  map[bool]bool
 		MapBadKeyType  map[complex64]int
 		BadArrayValue  []int
+		BadMapKey      map[time.Time]string
 	}
 
 	values := url.Values{
@@ -670,6 +679,7 @@ func TestErrors(t *testing.T) {
 		"MapBadBoolKey[uh-huh]": []string{"true"},
 		"MapBadKeyType[1.4]":    []string{"5"},
 		"BadArrayValue[0]":      []string{"badintval"},
+		"BadMapKey[badtime]":    []string{"badtime"},
 	}
 
 	var test TestError
@@ -678,6 +688,7 @@ func TestErrors(t *testing.T) {
 	decoder.RegisterCustomTypeFunc(func(vals []string) (interface{}, error) {
 		return nil, errors.New("Bad Type Conversion")
 	}, "")
+
 	errs := decoder.Decode(&test, values)
 	NotEqual(t, errs, nil)
 
@@ -720,6 +731,29 @@ func TestErrors(t *testing.T) {
 
 	k = err["BadArrayValue[0]"]
 	Equal(t, k.Error(), "Invalid Integer Value 'badintval' Type 'int' Namespace 'BadArrayValue[0]'")
+
+	type TestError2 struct {
+		BadMapKey map[time.Time]string
+	}
+
+	values2 := url.Values{
+		"BadMapKey[badtime]": []string{"badtime"},
+	}
+
+	var test2 TestError2
+	decoder2 := NewDecoder()
+	decoder2.RegisterCustomTypeFunc(func(vals []string) (interface{}, error) {
+		return time.Parse("2006-01-02", vals[0])
+	}, time.Time{})
+
+	errs = decoder2.Decode(&test2, values2)
+	NotEqual(t, errs, nil)
+
+	e = errs.Error()
+	NotEqual(t, e, "")
+
+	k = err["BadMapKey"]
+	Equal(t, k.Error(), "Unsupported Map Key 'badtime', Type 'time.Time' Namespace 'BadMapKey'")
 }
 
 func TestPanics(t *testing.T) {