specify custom session id with method and in init config

Author: Daniel Jih

amplitude.js

@@ -568,6 +568,9 @@ AmplitudeClient.prototype.init = function init(apiKey, opt_userId, opt_config, o
     this.options.userId = (type(opt_userId) === 'string' && !utils.isEmptyString(opt_userId) && opt_userId) ||
         this.options.userId || null;
 
+    // if custom session id specified in config, override what is stored in cookie
+    this._sessionId = this.options.sessionId > 0 ? this.options.sessionId : this._sessionId;
+
     // load unsent events and identifies before any attempt to log new ones
     if (this.options.saveEvents) {
       this._unsentEvents = this._loadSavedUnsentEvents(this.options.unsentKey);
@@ -1065,6 +1068,19 @@ AmplitudeClient.prototype.setDomain = function setDomain(domain) {
   }
 };
 
+AmplitudeClient.prototype.setSessionId = function setSessionId(sessionId) {
+  if (!utils.validateInput(sessionId, 'sessionId', 'number')) {
+    return;
+  }
+
+  try {
+    this._sessionId = sessionId;
+    _saveCookieData(this);
+  } catch (e) {
+    utils.log(e);
+  }
+};
+
 /**
  * Sets an identifier for the current user.
  * @public
@@ -5005,6 +5021,7 @@ module.exports = {
   includeGclid: false,
   saveParamsReferrerOncePerSession: true,
   deviceIdFromUrlParam: false,
+  sessionId: 0,
 };
 
 }, {"./language":29}],

amplitude.min.js

@@ -87,6 +87,9 @@ AmplitudeClient.prototype.init = function init(apiKey, opt_userId, opt_config, o
     this.options.userId = (type(opt_userId) === 'string' && !utils.isEmptyString(opt_userId) && opt_userId) ||
         this.options.userId || null;
 
+    // if custom session id specified in config, override what is stored in cookie
+    this._sessionId = this.options.sessionId > 0 ? this.options.sessionId : this._sessionId;
+
     // load unsent events and identifies before any attempt to log new ones
     if (this.options.saveEvents) {
       this._unsentEvents = this._loadSavedUnsentEvents(this.options.unsentKey);
@@ -584,6 +587,19 @@ AmplitudeClient.prototype.setDomain = function setDomain(domain) {
   }
 };
 
+AmplitudeClient.prototype.setSessionId = function setSessionId(sessionId) {
+  if (!utils.validateInput(sessionId, 'sessionId', 'number')) {
+    return;
+  }
+
+  try {
+    this._sessionId = sessionId;
+    _saveCookieData(this);
+  } catch (e) {
+    utils.log(e);
+  }
+};
+
 /**
  * Sets an identifier for the current user.
  * @public

src/amplitude-client.js

@@ -24,4 +24,5 @@ module.exports = {
   includeGclid: false,
   saveParamsReferrerOncePerSession: true,
   deviceIdFromUrlParam: false,
+  sessionId: 0,
 };