In previous blog when a Wechat user subscribes the subscription Wechat account, a new individual customer is automatically created in C4C system.

So technically Wechat is the source(sender) of dataflow and our C4C system is the dataflow target ( receiver ), and the nodejs server acts as a middleware.

In this blog, let’s try the other way around: suppose any one has made changes on this automatically created account in C4C system, the corresponding Wechat user will receive a notification in his/her Wechat app. Such notification is sent by C4C and Wechat app is the receiver.

(4) In nodejs server implementation, create a new field in config object:

• field name: indivudualCustomerNewurl
• field value: https:///sap/c4c/odata/cust/v1/zindividualcustomer/CustomerCommonCollection? $filter= Since the endpoint I configure in C4C system is: wechatjerry.herokuapp.com/c4c And when a given account is changed in C4C, a HTTP post with the following kind of payload will be sent to this endpoint:

{" businessObject ":" CUSTOMER ", "businessObjectId" :"00163E20C9511EE7B8975BD4AB3F60C0 ", "the event" : ""," odataServiceEndpoint ":" HTTPS:/ / < your tenant > / SAP/byd/odata/v1 / zindividualcustomer/CustomerCommonCollection e20c9511ee7b8975bd4ab3f60c0 (' 00163 ') "}
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So in nodejs server, I have to react to this Post request.

Main logic is implemented in module notifyWechatUser, which uses the guid of changed Customer BO instance as an input parameter.

Inside the implementation of notifyWechatUser, which consists of two steps:

function notifyWechatUser(uuid,res){
  console.log("begin to read uuid: " + uuid);
  _getAccount(uuid).then(function(wechatID){
    res.status(200).end();
    sendMessage(wechatID, "Dear user, A kind reminder: your C4C account is changed in the system.");
  });
}
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(1) call _getAccount to get the WechatID stored on Common node of Customer BO via OData call.

(2) sendMessage to send a hard coded sentence to the corresponding Wechat user.

var config = require(".. /.. /config.js");
var request = require("request");

function printObject(oData){
	for( var a in oData){
		console.log("key: " + a);
		console.log("value: " + oData[a]);
		if( typeof oData[a] === "object"){ printObject(oData[a]); }}}function sendWCMeaasge(toUser,sMessage){
	console.log("begin to send message to user: " + toUser + " with message: " + sMessage);
    var options = {
            url:"https://api.weixin.qq.com/cgi-bin/message/custom/send?access_token=" +
            config.accessToken, 
            method: "POST".json:true.headers: {
            	"content-type": "application/json"},
            body: {"touser":toUser,
              "msgtype":"text"."text":
              {
                   "content":sMessage
              }
                }
          };
      request(options,function(error,response,data){
      	console.log("error? " + error);
        console.log("response: " + response);
        console.log("data: " + data);
        console.log("response...............................................");
        //printObject(response);
        console.log("data.....................................................");
        console.log("Status message: " + response.statusMessage);
        console.log("Data: " + data.errmsg);
      });
  }

module.exports = sendWCMeaasge;
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