Add DisableBodyConsumptionOnUnmarshal configuration field as discussed on [chat](https://kataras.rocket.chat/channel/iris). Read HISTORY.md

HISTORY.md

@@ -2,6 +2,25 @@
 
 **How to upgrade**: remove your `$GOPATH/src/github.com/kataras` folder, open your command-line and execute this command: `go get -u github.com/kataras/iris/iris`.
 
+## 6.1.2 -> 6.1.3
+
+- Added a configuration field `iris.Config.DisableBodyConsumptionOnUnmarshal`
+
+```go
+// DisableBodyConsumptionOnUnmarshal manages the reading behavior of the context's body readers/binders.
+// If setted to true then it
+// disables the body consumption by the `context.UnmarshalBody/ReadJSON/ReadXML`.
+//
+// By-default io.ReadAll` is used to read the body from the `context.Request.Body which is an `io.ReadCloser`,
+// if this field setted to true then a new buffer will be created to read from and the request body.
+// The body will not be changed and existing data before the context.UnmarshalBody/ReadJSON/ReadXML will be not consumed.
+DisableBodyConsumptionOnUnmarshal bool
+```
+
+If that option is setted to true then you can read more than one times from the same `context.Request.Body`.
+Defaults to false because the majority of developers expecting request body to be empty after unmarshal.
+
+
 ## 6.1.1 -> 6.1.2
 
 Better internalization and localization support, with ability to change the cookie's key and context's keys.

README.md

@@ -20,7 +20,7 @@
 <br/>
 
 
-<a href="https://github.com/kataras/iris/blob/master/HISTORY.md"><img src="https://img.shields.io/badge/%20version%20-%206.1.2%20-blue.svg?style=flat-square" alt="CHANGELOG/HISTORY"></a>
+<a href="https://github.com/kataras/iris/blob/master/HISTORY.md"><img src="https://img.shields.io/badge/%20version%20-%206.1.3%20-blue.svg?style=flat-square" alt="CHANGELOG/HISTORY"></a>
 
 <a href="https://github.com/iris-contrib/examples"><img src="https://img.shields.io/badge/%20examples-repository-3362c2.svg?style=flat-square" alt="Examples"></a>
 
@@ -209,7 +209,7 @@ Besides the fact that we have a [community chat][Chat] for questions or reports
 Versioning
 ------------
 
-Current: **v6.1.2**
+Current: **v6.1.3**
 
 v5: https://github.com/kataras/iris/tree/5.0.0
 

configuration.go

@@ -150,6 +150,15 @@ type Configuration struct {
 	// Default is false
 	DisableBanner bool
 
+	// DisableBodyConsumptionOnUnmarshal manages the reading behavior of the context's body readers/binders.
+	// If setted to true then it
+	// disables the body consumption by the `context.UnmarshalBody/ReadJSON/ReadXML`.
+	//
+	// By-default io.ReadAll` is used to read the body from the `context.Request.Body which is an `io.ReadCloser`,
+	// if this field setted to true then a new buffer will be created to read from and the request body.
+	// The body will not be changed and existing data before the context.UnmarshalBody/ReadJSON/ReadXML will be not consumed.
+	DisableBodyConsumptionOnUnmarshal bool
+
 	// LoggerOut is the destination for output
 	//
 	// Default is os.Stdout
@@ -349,6 +358,19 @@ var (
 		}
 	}
 
+	// OptionDisableBodyConsumptionOnUnmarshal manages the reading behavior of the context's body readers/binders.
+	// If setted to true then it
+	// disables the body consumption by the `context.UnmarshalBody/ReadJSON/ReadXML`.
+	//
+	// By-default io.ReadAll` is used to read the body from the `context.Request.Body which is an `io.ReadCloser`,
+	// if this field setted to true then a new buffer will be created to read from and the request body.
+	// The body will not be changed and existing data before the context.UnmarshalBody/ReadJSON/ReadXML will be not consumed.
+	OptionDisableBodyConsumptionOnUnmarshal = func(val bool) OptionSet {
+		return func(c *Configuration) {
+			c.DisableBodyConsumptionOnUnmarshal = val
+		}
+	}
+
 	// OptionLoggerOut is the destination for output
 	//
 	// Default is os.Stdout
@@ -472,6 +494,7 @@ func DefaultConfiguration() Configuration {
 		EnablePathEscape:                  DefaultEnablePathEscape,
 		FireMethodNotAllowed:              false,
 		DisableBanner:                     false,
+		DisableBodyConsumptionOnUnmarshal: false,
 		LoggerOut:                         DefaultLoggerOut,
 		LoggerPreffix:                     DefaultLoggerPreffix,
 		DisableTemplateEngines:            false,

context.go

@@ -548,6 +548,12 @@ func (ctx *Context) UnmarshalBody(v interface{}, unmarshaler Unmarshaler) error
 		return err
 	}
 
+	if ctx.framework.Config.DisableBodyConsumptionOnUnmarshal {
+		// * remember, Request.Body has no Bytes(), we have to consume them first
+		// and after re-set them to the body, this is the only solution.
+		ctx.Request.Body = ioutil.NopCloser(bytes.NewBuffer(rawData))
+	}
+
 	// check if the v contains its own decode
 	// in this case the v should be a pointer also,
 	// but this is up to the user's custom Decode implementation*

context_test.go

@@ -251,6 +251,13 @@ func testUnmarshaler(t *testing.T, tb *testBinder,
 		if write != nil {
 			write(ctx)
 		}
+
+		if iris.Config.DisableBodyConsumptionOnUnmarshal {
+			rawData, _ := ioutil.ReadAll(ctx.Request.Body)
+			if len(rawData) == 0 {
+				t.Fatalf("Expected data to NOT BE consumed by the previous UnmarshalBody call but we got empty body.")
+			}
+		}
 	}
 
 	iris.Post("/bind_req_body", h)
@@ -301,7 +308,6 @@ func TestContextBinders(t *testing.T) {
 		expectedObj.Birth + `</birth><stars>` +
 		strconv.Itoa(expectedObj.Stars) + `</stars></info>`
 
-	// JSON
 	vXML := &testBinder{&testBinderXMLData{},
 		iris.UnmarshalerFunc(xml.Unmarshal), false}
 	testUnmarshaler(
@@ -315,6 +321,18 @@ func TestContextBinders(t *testing.T) {
 		Status(iris.StatusOK).
 		Body().Equal(expectedAndPassedObjText)
 
+	// JSON with DisableBodyConsumptionOnUnmarshal
+	iris.Config.DisableBodyConsumptionOnUnmarshal = true
+	testUnmarshaler(
+		t,
+		vJSON,
+		func(ctx *iris.Context) {
+			ctx.JSON(iris.StatusOK, vJSON.vp)
+		}).
+		WithJSON(passed).
+		Expect().
+		Status(iris.StatusOK).
+		JSON().Object().Equal(expectedObject)
 }
 
 func TestContextReadForm(t *testing.T) {

iris.go

@@ -81,7 +81,7 @@ const (
 	// IsLongTermSupport flag is true when the below version number is a long-term-support version
 	IsLongTermSupport = false
 	// Version is the current version number of the Iris web framework
-	Version = "6.1.2"
+	Version = "6.1.3"
 
 	banner = `         _____      _
         |_   _|    (_)