Server-Server integration between NodeJS and Google APIs to get page views on pages and top viewed pages on your website

google-analytics-server.js

var {google} = require('googleapis'), // official https://github.com/google/google-api-nodejs-client npm module
    analyticsreporting = google.analyticsreporting('v4'),
    key = require('./private.json');// Secure server key file(in JSON) dowloaded from Google
    
    
    /********************** GET PAGE VIEWS *******************/
    app.get('/analytics/report', cors(corsOptions), function(req,res){

      //passed parameter
      var url = req.query.url;

      var jwtClient = new google.auth.JWT(
        key.client_email,
        null,
        key.private_key,
        ['https://www.googleapis.com/auth/analytics.readonly'], // an array of auth scopes
        null
      );

      jwtClient.authorize(function (err, tokens) {
        if (err) {
          console.log(err);
          return;
        }

        // Make an authorized request to anayltics
        var params  = {
                        "auth": jwtClient,
                        "headers": {
                            "Content-Type": "application/json"
                        },
                        "resource":{
                          "reportRequests": [
                            {
                              "viewId": "yourViewId", // your view Id from goofle
                              "samplingLevel": "DEFAULT",
                              "filtersExpression": "ga:pagePath=="+url, // url passed in query parameter
                              "dateRanges": [
                                {
                                  "startDate": "2008-03-05",
                                  "endDate": "yesterday"
                                }
                              ],
                              "metrics": [
                                {
                                  "expression": "ga:pageviews",
                                  "alias": ""
                                }
                              ],
                              "dimensions": [
                                {
                                  "name": "ga:pagePath"
                                }
                              ]
                            }
                          ]
                        }
                      };

        analyticsreporting.reports.batchGet(params, function(err, resp){
          if(resp){
            var count = resp.data.reports[0].data.totals[0].values[0]; // actual page view count for passed url
            res.json({"count" : count});
          }else{
            res.json({"error" : true});
          }
        });
      });
    });

    /********************** GET TOP POSTS **************************/
    app.get('/analytics/posts', cors(corsOptions), function(req,res){

      //passed parameter
      var top = req.query.top || 15;

      var jwtClient = new google.auth.JWT(
        key.client_email,
        null,
        key.private_key,
        ['https://www.googleapis.com/auth/analytics.readonly'], // an array of auth scopes
        null
      );

      jwtClient.authorize(function (err, tokens) {
        if (err) {
          console.log(err);
          return;
        }

        // Make an authorized request to anayltics
        var params  = {
                        "auth": jwtClient,
                        "headers": {
                            "Content-Type": "application/json"
                        },
                        "resource":{
                          "reportRequests": [
                            {
                              "viewId": "yourViewId", // your view Id from goofle
                              "samplingLevel": "DEFAULT",
                              "dateRanges": [
                                {
                                  "startDate": "2008-03-05",
                                  "endDate": "yesterday"
                                }
                              ],
                              "metrics": [
                                {
                                  "expression": "ga:pageviews",
                                  "alias": ""
                                }
                              ],
                              "dimensions": [
                                {
                                  "name": "ga:pagePath"
                                },
                                {
                                  "name": "ga:pageTitle" // EXTRA DIMENSION TO GET THE TITLE OF PAGES
                                }
                              ]
                            }
                          ]
                        }
                      };

        analyticsreporting.reports.batchGet(params, function(err, resp){
          if(resp){
            var lst = orderLstInDesc(extractKeyDate(resp));
            res.json({top : lst.slice(0, top)});
          }else{
            res.json({"error" : true});
          }
        });
      });
    });

    //Method to order json object with a attribute
    function orderLstInDesc(json){
      var orderedLst = [];
      var keysSorted = Object.keys(json).sort(function(a,b){return json[b].count-json[a].count});
      for(var i = 0; i < keysSorted.length; i++){
        //remove home page
        if(keysSorted[i] !== 'total' && keysSorted[i] !== '/'){
          orderedLst.push({
                            url : keysSorted[i], 
                            title : json[keysSorted[i]].title,
                            count : json[keysSorted[i]].count
                          });
        }
      }
      return orderedLst;
    }


    //Array to exclude some pages like home page, about page etc.
    var excludeTitles = [
                      'home',
                      'about',
                      'contact'
                    ];

    function checkKeywordsToExclude(title){
      for(var i = 0; i < excludeTitles.length; i++){
        if(title.toLowerCase().includes(excludeTitles[i].toLowerCase())){
          return true;
        }
      }
      return false;
    }

    //returns a map of url with key information
    //like title and page views on urls
    //example : {"/path/to/page" : 
    //            { "title" : "page title", "count" : 200}
    //          }
    function extractKeyDate(data){
      var keyData = {};
      var lines = data.reports[0].data.rows;
      for(var i = 0 ; i < lines.length; i++){
        var key = lines[i].dimensions[0];
        var title;
        if(!checkKeywordsToExclude(lines[i].dimensions[1])){
          title = lines[i].dimensions[1];
        }
        var val = parseInt(lines[i].metrics[0].values[0]);
        if(keyData[key]){
          keyData[key].count += val;
          keyData[key].title = title;
        }else{
          keyData[key] = { title : title, count : val };
        }
      }
      return keyData;
    }