From 898d805ef607ddfc082c3cf50a486f0a64d0c75d Mon Sep 17 00:00:00 2001
From: "Gerasimos (Makis) Maropoulos" <kataras2006@hotmail.com>
Date: Fri, 24 Jul 2020 20:49:43 +0300
Subject: [PATCH] export the Form and Query decoders in order to be customized
 by Iris users and ignore unknown url query parameters instead of giving an
 ErrPath

relative to: https://github.com/kataras/iris/issues/1566
---
 decoder.go     | 15 ++++++++++-----
 go.mod         |  2 +-
 schema.go      | 15 ++++++---------
 schema_test.go | 44 ++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 61 insertions(+), 15 deletions(-)
 create mode 100644 schema_test.go

diff --git a/decoder.go b/decoder.go
index 0deec30..18222a1 100644
--- a/decoder.go
+++ b/decoder.go
@@ -26,13 +26,15 @@ type Decoder struct {
 
 // AddAliasTag adds a tag used to locate custom field aliases.
 // Defaults are "schema", "form" and "url".
-func (d *Decoder) AddAliasTag(tag ...string) {
+func (d *Decoder) AddAliasTag(tag ...string) *Decoder {
 	d.cache.tags = append(d.cache.tags, tag...)
+	return d
 }
 
 // SetAliasTag overrides the tags.
-func (d *Decoder) SetAliasTag(tag ...string) {
+func (d *Decoder) SetAliasTag(tag ...string) *Decoder {
 	d.cache.tags = tag
+	return d
 }
 
 // ZeroEmpty controls the behaviour when the decoder encounters empty values
@@ -43,8 +45,9 @@ func (d *Decoder) SetAliasTag(tag ...string) {
 //
 // The default value is false, that is empty values do not change
 // the value of the struct field.
-func (d *Decoder) ZeroEmpty(z bool) {
+func (d *Decoder) ZeroEmpty(z bool) *Decoder {
 	d.zeroEmpty = z
+	return d
 }
 
 // IgnoreUnknownKeys controls the behaviour when the decoder encounters unknown
@@ -55,13 +58,15 @@ func (d *Decoder) ZeroEmpty(z bool) {
 // will still be decoded in to the target struct.
 //
 // To preserve backwards compatibility, the default value is false.
-func (d *Decoder) IgnoreUnknownKeys(i bool) {
+func (d *Decoder) IgnoreUnknownKeys(i bool) *Decoder {
 	d.ignoreUnknownKeys = i
+	return d
 }
 
 // RegisterConverter registers a converter function for a custom type.
-func (d *Decoder) RegisterConverter(value interface{}, converterFunc Converter) {
+func (d *Decoder) RegisterConverter(value interface{}, converterFunc Converter) *Decoder {
 	d.cache.registerConverter(value, converterFunc)
+	return d
 }
 
 // Decode decodes a map[string][]string to a struct.
diff --git a/go.mod b/go.mod
index 5a05d0c..05b3a83 100644
--- a/go.mod
+++ b/go.mod
@@ -1,3 +1,3 @@
 module github.com/iris-contrib/schema
 
-go 1.12
+go 1.14
diff --git a/schema.go b/schema.go
index 50123e6..b76601b 100644
--- a/schema.go
+++ b/schema.go
@@ -2,15 +2,12 @@ package schema
 
 var (
 	defaultDecoder = NewDecoder() // form, url, schema.
-	formDecoder    = NewDecoder()
-	queryDecoder   = NewDecoder()
+	// Form Decoder. The default instance for DecodeForm function.
+	Form = NewDecoder().SetAliasTag("form")
+	// Query Decoder. The default instance for DecodeQuery function.
+	Query = NewDecoder().SetAliasTag("url").IgnoreUnknownKeys(true) // allow unknown url queries.
 )
 
-func init() {
-	formDecoder.SetAliasTag("form")
-	queryDecoder.SetAliasTag("url")
-}
-
 // Decode maps "values" to "ptr".
 // With one of the "form", "url" or "schema" tag fields that can override the field's name mapping to key.
 func Decode(values map[string][]string, ptr interface{}) error {
@@ -20,13 +17,13 @@ func Decode(values map[string][]string, ptr interface{}) error {
 // DecodeForm maps "values" to "ptr".
 // With "form" tag for fields.
 func DecodeForm(values map[string][]string, ptr interface{}) error {
-	return formDecoder.Decode(ptr, values)
+	return Form.Decode(ptr, values)
 }
 
 // DecodeQuery maps "values" to "ptr".
 // With "url" tag for fields.
 func DecodeQuery(values map[string][]string, ptr interface{}) error {
-	return queryDecoder.Decode(ptr, values)
+	return Query.Decode(ptr, values)
 }
 
 // IsErrPath reports whether the incoming error is type of unknown field passed,
diff --git a/schema_test.go b/schema_test.go
new file mode 100644
index 0000000..67f99af
--- /dev/null
+++ b/schema_test.go
@@ -0,0 +1,44 @@
+// package schema_test black box testing
+package schema_test
+
+import (
+	"testing"
+
+	"github.com/kataras/iris/v12"
+	"github.com/kataras/iris/v12/httptest"
+)
+
+type testRequest struct {
+	Username string     `form:"test_username" json:"test_username"`
+	Data     []testData `form:"test_data" json:"test_data"`
+	Other    int        `form:"test_other" json:"test_other"`
+}
+
+type testData struct {
+	Name string `form:"test_data_name" json:"test_data_name"`
+}
+
+func TestSchemaSliceFieldTag(t *testing.T) {
+	app := iris.New()
+	app.Post("/", func(ctx iris.Context) {
+		var p testRequest
+		if err := ctx.ReadForm(&p); err != nil && iris.IsErrPath(err) {
+			t.Fatal(err)
+		}
+
+		ctx.JSON(p)
+	})
+
+	payload := testRequest{
+		Username: "test username",
+		Data: []testData{
+			{Name: "test data name 1"},
+			{Name: "test data name 2"},
+			{Name: "test data name 3"},
+		},
+		Other: 42,
+	}
+
+	e := httptest.New(t, app)
+	e.POST("/").WithForm(payload).Expect().Status(iris.StatusOK).JSON().Equal(payload)
+}