feat(context): add BindQuery func (#1029)

* feat(context): add BindQuery func, only parse/bind the query string params.

* docs(readme): add BindQuery section.

* docs(readme): fix import.

* docs(readme): separate import

binding/binding.go

@@ -39,6 +39,7 @@ var (
 	JSON          = jsonBinding{}
 	XML           = xmlBinding{}
 	Form          = formBinding{}
+	Query         = queryBinding{}
 	FormPost      = formPostBinding{}
 	FormMultipart = formMultipartBinding{}
 	ProtoBuf      = protobufBinding{}

binding/binding_test.go

@@ -67,6 +67,18 @@ func TestBindingForm2(t *testing.T) {
 		"", "")
 }
 
+func TestBindingQuery(t *testing.T) {
+	testQueryBinding(t, "POST",
+		"/?foo=bar&bar=foo", "/",
+		"foo=unused", "bar2=foo")
+}
+
+func TestBindingQuery2(t *testing.T) {
+	testQueryBinding(t, "GET",
+		"/?foo=bar&bar=foo", "/?bar2=foo",
+		"foo=unused", "")
+}
+
 func TestBindingXML(t *testing.T) {
 	testBodyBinding(t,
 		XML, "xml",
@@ -204,6 +216,21 @@ func testFormBinding(t *testing.T, method, path, badPath, body, badBody string)
 	assert.Error(t, err)
 }
 
+func testQueryBinding(t *testing.T, method, path, badPath, body, badBody string) {
+	b := Query
+	assert.Equal(t, b.Name(), "query")
+
+	obj := FooBarStruct{}
+	req := requestWithBody(method, path, body)
+	if method == "POST" {
+		req.Header.Add("Content-Type", MIMEPOSTForm)
+	}
+	err := b.Bind(req, &obj)
+	assert.NoError(t, err)
+	assert.Equal(t, obj.Foo, "bar")
+	assert.Equal(t, obj.Bar, "foo")
+}
+
 func testBodyBinding(t *testing.T, b Binding, name, path, badPath, body, badBody string) {
 	assert.Equal(t, b.Name(), name)
 

binding/query.go

@@ -0,0 +1,23 @@
+// Copyright 2017 Manu Martinez-Almeida.  All rights reserved.
+// Use of this source code is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+package binding
+
+import (
+	"net/http"
+)
+
+type queryBinding struct{}
+
+func (queryBinding) Name() string {
+	return "query"
+}
+
+func (queryBinding) Bind(req *http.Request, obj interface{}) error {
+	values := req.URL.Query()
+	if err := mapForm(obj, values); err != nil {
+		return err
+	}
+	return validate(obj)
+}