Tutorial on WeChat public platform development (2) Basic Principles and message interfaces, basic principles of the public

Public platform development tutorial (ii) basic principles and message interface summary, basic principles of the public

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.

2. splice the three parameter strings into one string for sha1 Encryption

3. 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

 <xml> <ToUserName><![CDATA[toUser]]></ToUserName> <FromUserName><![CDATA[fromUser]]></FromUserName>  <CreateTime>1348831860</CreateTime> <MsgType><![CDATA[text]]></MsgType> <Content><![CDATA[this is a test]]></Content> <MsgId>1234567890123456</MsgId> </xml>

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

 <xml> <ToUserName><![CDATA[toUser]]></ToUserName> <FromUserName><![CDATA[fromUser]]></FromUserName> <CreateTime>1348831860</CreateTime> <MsgType><![CDATA[image]]></MsgType> <PicUrl><![CDATA[this is a url]]></PicUrl> <MsgId>1234567890123456</MsgId> </xml>

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

<Xml> <ToUserName> <! [CDATA [toUser]> </ToUserName> <FromUserName> <! [CDATA [fromUser]> </FromUserName> <CreateTime> 1351776360 </CreateTime> <MsgType> <! </MsgType> <Location_X> 23.134521 </Location_X> <Location_Y> 113.358803 </Location_Y> <Scale> 20 </Scale> <Label> <! [CDATA [location information]> </Label> <MsgId> 1234567890123456 </MsgId> </xml>

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

<Xml> <ToUserName> <! [CDATA [toUser]> </ToUserName> <FromUserName> <! [CDATA [fromUser]> </FromUserName> <CreateTime> 1351776360 </CreateTime> <MsgType> <! [CDATA [link]> </MsgType> <Title> <! [CDATA [official website of the public platform]> </Title> <Description> <! [CDATA [official website of the public platform]> </Description> <Url> <! </Url> <MsgId> 1234567890123456 </MsgId> </xml>

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.

<xml><ToUserName><![CDATA[toUser]]></ToUserName><FromUserName><![CDATA[FromUser]]></FromUserName><CreateTime>123456789</CreateTime><MsgType><![CDATA[event]]></MsgType><Event><![CDATA[EVENT]]></Event><EventKey><![CDATA[EVENTKEY]]></EventKey></xml>

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 text, text, voice, video, music ).

If the server fails to receive the response within five seconds, the connection will be disconnected.

The xml structure of the reply is as follows:

Reply text message

 <xml> <ToUserName><![CDATA[toUser]]></ToUserName> <FromUserName><![CDATA[fromUser]]></FromUserName> <CreateTime>12345678</CreateTime> <MsgType><![CDATA[text]]></MsgType> <Content><![CDATA[content]]></Content> </xml>

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

 <xml> <ToUserName><![CDATA[toUser]]></ToUserName> <FromUserName><![CDATA[fromUser]]></FromUserName> <CreateTime>12345678</CreateTime> <MsgType><![CDATA[music]]></MsgType> <Music> <Title><![CDATA[TITLE]]></Title> <Description><![CDATA[DESCRIPTION]]></Description> <MusicUrl><![CDATA[MUSIC_Url]]></MusicUrl> <HQMusicUrl><![CDATA[HQ_MUSIC_Url]]></HQMusicUrl> </Music> </xml>

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

 <xml> <ToUserName><![CDATA[toUser]]></ToUserName> <FromUserName><![CDATA[fromUser]]></FromUserName> <CreateTime>12345678</CreateTime> <MsgType><![CDATA[news]]></MsgType> <ArticleCount>2</ArticleCount> <Articles> <item> <Title><![CDATA[title1]]></Title>  <Description><![CDATA[description1]]></Description> <PicUrl><![CDATA[picurl]]></PicUrl> <Url><![CDATA[url]]></Url> </item> <item> <Title><![CDATA[title]]></Title> <Description><![CDATA[description]]></Description> <PicUrl><![CDATA[picurl]]></PicUrl> <Url><![CDATA[url]]></Url> </item> </Articles> </xml>

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 larger image size is 640*320, and the smaller 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

The above is all the content of this article. I hope it will be helpful for your learning and support for helping customers.