From : Puru Choudhary at https://www.terminusapp.com/blog/add-utm-referrer-lead-forms/ Hosted by Puru at: https://d12ue6f2329cfl.cloudfront.net/resources/utm_form-1.0.3.min.js

new_gist_file.js

var UtmCookie;UtmCookie=function(){function UtmCookie(options){null==options&&(options={}),this._cookieNamePrefix="_uc_",this._domain=options.domain,this._sessionLength=options.sessionLength||1,this._cookieExpiryDays=options.cookieExpiryDays||365,this._additionalParams=options.additionalParams||[],this._utmParams=["utm_source","utm_medium","utm_campaign","utm_term","utm_content"],this.writeInitialReferrer(),this.writeLastReferrer(),this.writeInitialLandingPageUrl(),this.setCurrentSession(),this.additionalParamsPresentInUrl()&&this.writeAdditionalParams(),this.utmPresentInUrl()&&this.writeUtmCookieFromParams()}return UtmCookie.prototype.createCookie=function(name,value,days,path,domain,secure){var cookieDomain,cookieExpire,cookiePath,cookieSecure,date,expireDate;expireDate=null,days&&(date=new Date,date.setTime(date.getTime()+24*days*60*60*1e3),expireDate=date),cookieExpire=null!=expireDate?"; expires="+expireDate.toGMTString():"",cookiePath=null!=path?"; path="+path:"; path=/",cookieDomain=null!=domain?"; domain="+domain:"",cookieSecure=null!=secure?"; secure":"",document.cookie=this._cookieNamePrefix+name+"="+escape(value)+cookieExpire+cookiePath+cookieDomain+cookieSecure},UtmCookie.prototype.readCookie=function(name){var c,ca,i,nameEQ;for(nameEQ=this._cookieNamePrefix+name+"=",ca=document.cookie.split(";"),i=0;i<ca.length;){for(c=ca[i];" "===c.charAt(0);)c=c.substring(1,c.length);if(0===c.indexOf(nameEQ))return c.substring(nameEQ.length,c.length);i++}return null},UtmCookie.prototype.eraseCookie=function(name){this.createCookie(name,"",-1,null,this._domain)},UtmCookie.prototype.getParameterByName=function(name){var regex,regexS,results;return name=name.replace(/[\[]/,"\\[").replace(/[\]]/,"\\]"),regexS="[\\?&]"+name+"=([^&#]*)",regex=new RegExp(regexS),results=regex.exec(window.location.search),results?decodeURIComponent(results[1].replace(/\+/g," ")):""},UtmCookie.prototype.additionalParamsPresentInUrl=function(){var j,len,param,ref;for(ref=this._additionalParams,j=0,len=ref.length;len>j;j++)if(param=ref[j],this.getParameterByName(param))return!0;return!1},UtmCookie.prototype.utmPresentInUrl=function(){var j,len,param,ref;for(ref=this._utmParams,j=0,len=ref.length;len>j;j++)if(param=ref[j],this.getParameterByName(param))return!0;return!1},UtmCookie.prototype.writeCookie=function(name,value){this.createCookie(name,value,this._cookieExpiryDays,null,this._domain)},UtmCookie.prototype.writeAdditionalParams=function(){var j,len,param,ref,value;for(ref=this._additionalParams,j=0,len=ref.length;len>j;j++)param=ref[j],value=this.getParameterByName(param),this.writeCookie(param,value)},UtmCookie.prototype.writeUtmCookieFromParams=function(){var j,len,param,ref,value;for(ref=this._utmParams,j=0,len=ref.length;len>j;j++)param=ref[j],value=this.getParameterByName(param),this.writeCookie(param,value)},UtmCookie.prototype.writeCookieOnce=function(name,value){var existingValue;existingValue=this.readCookie(name),existingValue||this.writeCookie(name,value)},UtmCookie.prototype._sameDomainReferrer=function(referrer){var hostname;return hostname=document.location.hostname,referrer.indexOf(this._domain)>-1||referrer.indexOf(hostname)>-1},UtmCookie.prototype._isInvalidReferrer=function(referrer){return""===referrer||void 0===referrer},UtmCookie.prototype.writeInitialReferrer=function(){var value;value=document.referrer,this._isInvalidReferrer(value)&&(value="direct"),this.writeCookieOnce("referrer",value)},UtmCookie.prototype.writeLastReferrer=function(){var value;value=document.referrer,this._sameDomainReferrer(value)||(this._isInvalidReferrer(value)&&(value="direct"),this.writeCookie("last_referrer",value))},UtmCookie.prototype.writeInitialLandingPageUrl=function(){var value;value=this.cleanUrl(),value&&this.writeCookieOnce("initial_landing_page",value)},UtmCookie.prototype.initialReferrer=function(){return this.readCookie("referrer")},UtmCookie.prototype.lastReferrer=function(){return this.readCookie("last_referrer")},UtmCookie.prototype.initialLandingPageUrl=function(){return this.readCookie("initial_landing_page")},UtmCookie.prototype.incrementVisitCount=function(){var cookieName,existingValue,newValue;cookieName="visits",existingValue=parseInt(this.readCookie(cookieName),10),newValue=1,newValue=isNaN(existingValue)?1:existingValue+1,this.writeCookie(cookieName,newValue)},UtmCookie.prototype.visits=function(){return this.readCookie("visits")},UtmCookie.prototype.setCurrentSession=function(){var cookieName,existingValue;cookieName="current_session",existingValue=this.readCookie(cookieName),existingValue||(this.createCookie(cookieName,"true",this._sessionLength/24,null,this._domain),this.incrementVisitCount())},UtmCookie.prototype.cleanUrl=function(){var cleanSearch;return cleanSearch=window.location.search.replace(/utm_[^&]+&?/g,"").replace(/&$/,"").replace(/^\?$/,""),window.location.origin+window.location.pathname+cleanSearch+window.location.hash},UtmCookie}();var UtmForm,_uf;UtmForm=function(){function UtmForm(options){null==options&&(options={}),this._utmParamsMap={},this._utmParamsMap.utm_source=options.utm_source_field||"USOURCE",this._utmParamsMap.utm_medium=options.utm_medium_field||"UMEDIUM",this._utmParamsMap.utm_campaign=options.utm_campaign_field||"UCAMPAIGN",this._utmParamsMap.utm_content=options.utm_content_field||"UCONTENT",this._utmParamsMap.utm_term=options.utm_term_field||"UTERM",this._additionalParamsMap=options.additional_params_map||{},this._initialReferrerField=options.initial_referrer_field||"IREFERRER",this._lastReferrerField=options.last_referrer_field||"LREFERRER",this._initialLandingPageField=options.initial_landing_page_field||"ILANDPAGE",this._visitsField=options.visits_field||"VISITS",this._addToForm=options.add_to_form||"all",this._formQuerySelector=options.form_query_selector||"form",this.utmCookie=new UtmCookie({domain:options.domain,sessionLength:options.sessionLength,cookieExpiryDays:options.cookieExpiryDays,additionalParams:Object.getOwnPropertyNames(this._additionalParamsMap)}),"none"!==this._addToForm&&this.addAllFields()}return UtmForm.prototype.addAllFields=function(){var fieldName,param,ref,ref1;ref=this._utmParamsMap;for(param in ref)fieldName=ref[param],this.addFormElem(fieldName,this.utmCookie.readCookie(param));ref1=this._additionalParamsMap;for(param in ref1)fieldName=ref1[param],this.addFormElem(fieldName,this.utmCookie.readCookie(param));this.addFormElem(this._initialReferrerField,this.utmCookie.initialReferrer()),this.addFormElem(this._lastReferrerField,this.utmCookie.lastReferrer()),this.addFormElem(this._initialLandingPageField,this.utmCookie.initialLandingPageUrl()),this.addFormElem(this._visitsField,this.utmCookie.visits())},UtmForm.prototype.addFormElem=function(fieldName,fieldValue){var allForms,firstForm,form,i,len;if(fieldValue&&(allForms=document.querySelectorAll(this._formQuerySelector),allForms.length>0))if("first"===this._addToForm)firstForm=allForms[0],this.insertAfter(this.getFieldEl(fieldName,fieldValue),firstForm.lastChild);else for(i=0,len=allForms.length;len>i;i++)form=allForms[i],this.insertAfter(this.getFieldEl(fieldName,fieldValue),form.lastChild)},UtmForm.prototype.getFieldEl=function(fieldName,fieldValue){var fieldEl;return fieldEl=document.createElement("input"),fieldEl.type="hidden",fieldEl.name=fieldName,fieldEl.value=fieldValue,fieldEl},UtmForm.prototype.insertAfter=function(newNode,referenceNode){return referenceNode.parentNode.insertBefore(newNode,referenceNode.nextSibling)},UtmForm}(),_uf=window._uf||{},window.UtmForm=new UtmForm(_uf);