From 64c15a121b44a038131924a44f170ef8a09fd00f Mon Sep 17 00:00:00 2001
From: Wilson Wang <wangwscn@hotmail.com>
Date: Sun, 9 Apr 2017 09:58:35 -0700
Subject: [PATCH] Reuse Post Code (#28)

* add json omitempty on button Title field

Share Button only allows the Type field to be presented in the serialized data. Otherwise, you got facebook error:

"Facebook error : (#100) Param [elements][0][buttons][0][title] must be a non-empty UTF-8 encoded string"

* add attachement to senddata

* changes after pull request reviews

* add PostToMessenger method and ensure the result check in it

* change the function name
---
 response.go | 122 ++++++----------------------------------------------
 1 file changed, 13 insertions(+), 109 deletions(-)

diff --git a/response.go b/response.go
index f71bd02..92726f3 100644
--- a/response.go
+++ b/response.go
@@ -76,26 +76,7 @@ func (r *Response) TextWithReplies(message string, replies []QuickReply) error {
 			QuickReplies: replies,
 		},
 	}
-
-	data, err := json.Marshal(m)
-	if err != nil {
-		return err
-	}
-
-	req, err := http.NewRequest("POST", SendMessageURL, bytes.NewBuffer(data))
-	if err != nil {
-		return err
-	}
-
-	req.Header.Set("Content-Type", "application/json")
-	req.URL.RawQuery = "access_token=" + r.token
-
-	client := &http.Client{}
-
-	resp, err := client.Do(req)
-	defer resp.Body.Close()
-
-	return err
+	return r.DispatchMessage(&m)
 }
 
 // AttachmentWithReplies sends a attachment message with some replies
@@ -107,26 +88,7 @@ func (r *Response) AttachmentWithReplies(attachment *StructuredMessageAttachment
 			QuickReplies: replies,
 		},
 	}
-
-	data, err := json.Marshal(m)
-	if err != nil {
-		return err
-	}
-
-	req, err := http.NewRequest("POST", SendMessageURL, bytes.NewBuffer(data))
-	if err != nil {
-		return err
-	}
-
-	req.Header.Set("Content-Type", "application/json")
-	req.URL.RawQuery = "access_token=" + r.token
-
-	client := &http.Client{}
-
-	resp, err := client.Do(req)
-	defer resp.Body.Close()
-
-	return err
+	return r.DispatchMessage(&m)
 }
 
 // Image sends an image.
@@ -153,26 +115,7 @@ func (r *Response) Attachment(dataType AttachmentType, url string) error {
 			},
 		},
 	}
-
-	data, err := json.Marshal(m)
-	if err != nil {
-		return err
-	}
-
-	req, err := http.NewRequest("POST", SendMessageURL, bytes.NewBuffer(data))
-	if err != nil {
-		return err
-	}
-
-	req.Header.Set("Content-Type", "application/json")
-	req.URL.RawQuery = "access_token=" + r.token
-
-	client := &http.Client{}
-
-	resp, err := client.Do(req)
-	defer resp.Body.Close()
-
-	return err
+	return r.DispatchMessage(&m)
 }
 
 // AttachmentData sends an image, sound, video or a regular file to a chat via an io.Reader.
@@ -230,28 +173,7 @@ func (r *Response) ButtonTemplate(text string, buttons *[]StructuredMessageButto
 		},
 	}
 
-	data, err := json.Marshal(m)
-	if err != nil {
-		return err
-	}
-
-	req, err := http.NewRequest("POST", SendMessageURL, bytes.NewBuffer(data))
-	if err != nil {
-		return err
-	}
-
-	req.Header.Set("Content-Type", "application/json")
-	req.URL.RawQuery = "access_token=" + r.token
-
-	client := &http.Client{}
-
-	resp, err := client.Do(req)
-	if err != nil {
-		return err
-	}
-	defer resp.Body.Close()
-
-	return checkFacebookError(resp.Body)
+	return r.DispatchMessage(&m)
 }
 
 // GenericTemplate is a message which allows for structural elements to be sent
@@ -269,29 +191,7 @@ func (r *Response) GenericTemplate(elements *[]StructuredMessageElement) error {
 			},
 		},
 	}
-
-	data, err := json.Marshal(m)
-	if err != nil {
-		return err
-	}
-
-	req, err := http.NewRequest("POST", SendMessageURL, bytes.NewBuffer(data))
-	if err != nil {
-		return err
-	}
-
-	req.Header.Set("Content-Type", "application/json")
-	req.URL.RawQuery = "access_token=" + r.token
-
-	client := &http.Client{}
-
-	resp, err := client.Do(req)
-	if err != nil {
-		return err
-	}
-	defer resp.Body.Close()
-
-	return checkFacebookError(resp.Body)
+	return r.DispatchMessage(&m)
 }
 
 // SenderAction sends a info about sender action
@@ -300,7 +200,11 @@ func (r *Response) SenderAction(action string) error {
 		Recipient:    r.to,
 		SenderAction: action,
 	}
+	return r.DispatchMessage(&m)
+}
 
+// DispatchMessage posts the message to messenger, return the error if there's any
+func (r *Response) DispatchMessage(m interface{}) error {
 	data, err := json.Marshal(m)
 	if err != nil {
 		return err
@@ -314,14 +218,14 @@ func (r *Response) SenderAction(action string) error {
 	req.Header.Set("Content-Type", "application/json")
 	req.URL.RawQuery = "access_token=" + r.token
 
-	client := &http.Client{}
-
-	resp, err := client.Do(req)
+	resp, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return err
 	}
 	defer resp.Body.Close()
-
+	if resp.StatusCode == 200 {
+		return nil
+	}
 	return checkFacebookError(resp.Body)
 }