Added client UpdateMemberName function.

mailchimp.go

@@ -101,3 +101,15 @@ func (c *Client) Subscribe(email string, listId string) (interface{}, error) {
 	}
 	return v, nil
 }
+
+func (c *Client) UpdateMemberName(email string, listId string, firstName string, lastName string) (interface{}, error) {
+	data := &map[string]interface{}{
+		"merge_fields": &map[string]interface{}{"FNAME": firstName, "LNAME": lastName},
+	}
+	userID := memberIDFromEmail(email)
+	v, err := c.Do("PATCH", fmt.Sprintf("/lists/%s/members/%s", listId, userID), data)
+	if err != nil {
+		return v, err
+	}
+	return v, nil
+}

mailchimp_test.go

@@ -69,3 +69,25 @@ func TestSubscribe(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestUpdateMemberName(t *testing.T) {
+	server := httptest.NewServer(http.HandlerFunc(func(rw http.ResponseWriter, req *http.Request) {
+		rw.WriteHeader(200)
+		rw.Header().Set("Content-Type", "application/json")
+		fmt.Fprintln(rw, `{"member_fields":{"FNAME":"bob","LNAME":"brown"}}`)
+	}))
+	defer server.Close()
+
+	transport := &http.Transport{
+		Proxy: func(req *http.Request) (*url.URL, error) {
+			return url.Parse(server.URL)
+		},
+	}
+
+	client, _ := NewClient("a-lit11", &http.Client{Transport: transport})
+	client.BaseURL, _ = url.Parse("http://localhost/")
+	_, err := client.UpdateMemberName("me@matthewbrown.io", "abc_test", "bob", "brown")
+	if err != nil {
+		t.Fatal(err)
+	}
+}

util.go

@@ -0,0 +1,18 @@
+package mailchimp
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+)
+
+// From http://developer.mailchimp.com/documentation/mailchimp/guides/manage-subscribers-with-the-mailchimp-api/?_ga=1.198202223.1371869516.1465805004
+// "In previous versions of the API, we exposed internal database IDs eid and leid
+// for emails and list/email combinations. In API 3.0, we no longer use or expose
+// either of these IDs. Instead, we identify your subscribers by the MD5 hash of the
+// lowercase version of their email address so you can easily predict the API URL
+// of a subscriber’s data."
+func memberIDFromEmail(email string) string {
+	idData := []byte(email)
+	id := md5.Sum(idData)
+	return hex.EncodeToString(id[:])
+}