Basic principles of WeChat public platform development and messaging

The server is equivalent to a forwarding server. a terminal (such as a mobile phone or tablet) initiates a request to the server and forwards the request to the custom service (this is our specific implementation ). I. Basic principles

Before you start, you may be very interested in this, but you are quite confused. Is it complicated? Difficult to learn?

In fact, it is quite simple. To eliminate your concerns, I first briefly introduced the basic principles of the public platform.

The server is equivalent to a forwarding server. a terminal (such as a mobile phone or tablet) initiates a request to the server and forwards the request to the custom service (this is our specific implementation ).

After the service is processed, it is then volatile to the server, and then the server returns the specific response to the terminal.

The communication protocol is HTTP.

The data format is XML.

The specific process is shown in:

What we need to do is to respond to HTTP requests.

The specific request content is parsed according to the specific XML format. after processing, it must be returned according to the specific XML format.

We only need a simple implementation of HttpHandler.

Of course, the platform can also implement more complex services. for example, it can be used as an embedded browser. we can open the htm interface through a link and then implement our own logic.

II. Message Interface (official documentation)Message application interface

Click Apply and enter the url and token. you can enter the token as needed to generate a signature.

Website Access

After a public platform user submits information, the server sends a GET request to the URL filled in with four parameters:

Parameters	Description
Signature	Encrypted signature
Timestamp	Timestamp
Nonce	Random number
Echostr	Random string

The developer verifies the request by verifying signature (The following is a verification method ). If you confirm that the GET request is from the server, the echostr parameter is returned as is, and the access takes effect. Otherwise, the access fails.

Signature combines the token parameter entered by the developer with the timestamp parameter and nonce parameter in the request.

Encryption/verification process: 1. sort the tokens, timestamp, and nonce in lexicographic order. splice the three parameter strings into one string for sha1 encryption. the encrypted string obtained by the developer can be compared with signature to identify that the request comes from

Message push

When a common user sends a message to a public account, the server will POST the message to the entered URL. The structure is as follows:

Text message

 
  
  toUser
   
  fromUser
    
  
   1348831860
   
  text
   
  this is a test
   
  
   1234567890123456
   
 

Parameters	Description
ToUserName	DeveloperNo.
FromUserName	Sender account (one OpenID)
CreateTime	Message creation time (integer)
MsgType	Text
Content	Text message content
MsgId	Message id, 64-bit integer

Image message

 
  
  toUser
   
  fromUser
   
  
   1348831860
   
  image
   
  this is a url
   
  
   1234567890123456
   
 

Parameters	Description
ToUserName	DeveloperNo.
FromUserName	Sender account (one OpenID)
CreateTime	Message creation time (integer)
MsgType	Image
PicUrl	Image link
MsgId	Message id, 64-bit integer

Geographic location message

 
  toUser
  
  fromUser
  
  
   
1351776360
  
  location
  
  
   
23.134521
  
  
   
113.358803
  
  
   
20
  
  位置信息
  
   
1234567890123456
  
 

Parameters	Description
ToUserName	DeveloperNo.
FromUserName	Sender account (one OpenID)
CreateTime	Message creation time (integer)
MsgType	Location
Location_X	Geographic location and latitude
Location_Y	Geographic longitude
Scale	Map zoom
Label	Geographic location information
MsgId	Message id, 64-bit integer

Link message

 
  toUser
  
  fromUser
  
  
   
1351776360
  
  link
  
  <! [CDATA [Official website of the public platform]>
  公众平台官网链接
  
  url
  
  
   
1234567890123456
  
 

Parameters	Description
ToUserName	Recipient number
FromUserName	Sender ID. if it is a common user, it is an OpenID.
CreateTime	Message creation time
MsgType	Message type, link
Title	Message title
Description	Message description
Url	Message link
MsgId	Message id, 64-bit integer

Event push

Event push only supports version 4.5. Currently, you can enable event push, follow, and cancel follow event push for custom menu interfaces. Other functions will be available soon.

 
  toUser
  
  FromUser
  
  
   123456789
  
  event
  
  EVENT
  
  EVENTKEY
  
 

Parameters	Description
ToUserName	Recipient number
FromUserName	Sender ID. if it is a common user, it is an OpenID.
CreateTime	Message creation time
MsgType	Message type, event
Event	Event Type: subscribe, unsubscribe, and CLICK)
EventKey	Event KEY value, which corresponds to the KEY value in the custom menu interface

Message Reply

For each POST request, the developer returns a specific xml structure in the response packet to respond to the message (now supports replying to text, text, voice, video,Music).

The serverWithin five secondsIf no response is received, the connection will be disconnected.

The xml structure of the reply is as follows:

Reply text message

 
  
  toUser
   
  fromUser
   
  
   12345678
   
  text
   
  content
   
 

Parameters	Description
ToUserName	Recipient account (received OpenID)
FromUserName	Developer ID
CreateTime	Message creation time
MsgType	Text
Content	The content of the reply message. the length cannot exceed 2048 bytes.

Reply music message

 
  
  toUser
   
  fromUser
   
  
   12345678
   
  music
   
   
   <![CDATA[TITLE]]> 
   DESCRIPTION
    
   MUSIC_Url
    
   HQ_MUSIC_Url
    
   
 

Parameters	Description
ToUserName	Recipient account (received OpenID)
FromUserName	Developer ID
CreateTime	Message creation time
MsgType	Music
MusicUrl	Music link
HQMusicUrl	High-quality music link, which is preferred for playing music in WIFI environments

Reply to text message

 
  
  toUser
   
  fromUser
   
  
   12345678
   
  news
   2  
   
   <![CDATA[title1]]>  
   description1
    
   picurl
    
   url
    
   
   
   <![CDATA[title]]> 
   description
    
   picurl
    
   url
    
    
 

Parameters	Description
ToUserName	Recipient account (received OpenID)
FromUserName	Developer ID
CreateTime	Message creation time
MsgType	News
ArticleCount	Number of text and text messages, up to 10
Articles	Multiple text messages. The first item is a large image by default.
Title	Text message title
Description	Text message description
PicUrl	Image links. JPG and PNG formats are supported. The effect is 40*320, and the image size is 80*80.
Url	Click the text message jump link

Official interface documentation:

Http://mp.weixin.qq.com/wiki/index.php? Title = % E6 % B6 % 88% E6 % 81% AF % E6 % 8E % A5 % E5 % 8F % A3 % E6 % 8C % 87% E5 % 8D % 97

Notes

1. the user's OpenID is a fixed and unique string for a public number.

2. use port 80

Please note: We will explain the specific development process in the future. 3. message class diagram

For more articles about the basic principles and messaging of public platform development, please refer to the PHP Chinese website!