Replace old feedback URL params with new params

feedback-url-new-params.js

(function(document) {

  // Object to store new query params,
  // the current ones will be replaced,
  // new ones will be added to the url
  var newParams = {
    'recall-ui': '',
    'lambda-return-code': '',
    'recall-outcome': '',
    'recall-outcome-detail': '',
    'recall-last-update-date': ''
  };

  // Get the feedback link from DOM
  var feedbackSurveyLink = document.querySelector('a.appendClientID');

  // Check if feedback survey link exists on page
  if( !feedbackSurveyLink ) return;
  
  // Get the current feedback link url
  var feedbackURL = feedbackSurveyLink.href;

  // Check if feedback has a link
  if( !feedbackURL ) return;

  // Create new feedback url from the current url and the new params
  var newFeedbackURL = replaceURLQueryParams(feedbackURL, newParams);
  
  // Check if new feedback url was created successfully
  if( !newFeedbackURL ) return;

  // Replace current feedback url with new one
  feedbackSurveyLink.href = newFeedbackURL;
  
  function replaceURLQueryParams(currentURL, newParams) {
    // Seperate current url
    // delimited by '?' which is start
    // of the query params
    var seperatedURL = currentURL.split('?');

    // Check if URL has query params
    if( !seperatedURL || !seperatedURL[1] ) return;

    // Seperate params delimited by '&'
    var seperatedParams = seperatedURL[1].split('&');

    // Check if there is any params
    // and that it is an array
    if( !seperatedParams || !Array.isArray(seperatedParams) ) return;

    // Variables for later use
    var params = {};
    var paramsArray = [];
    var paramsString = '';
    var newURL = '';

    // Add/replace all params keys/values
    for(var i = 0; i < seperatedParams.length; i++) {
      var currentParam = seperatedParams[i];
      // Seperate param delimited by '='
      var paramKeyValue = currentParam.split('=');
      // Check if key/value exist and it is an array
      if( !paramKeyValue || !Array.isArray(paramKeyValue) ) continue;
      // Get both key and value from,
      // seperated string
      var key = paramKeyValue[0];
      var value = paramKeyValue[1];
      // Check if key and value exist
      if( !key || key == undefined || !value || value == undefined || value == 'undefined' ) continue;
      // Add key/value to the params array
      params[key] = value;
    }

    // Replace all params key/value with new ones
    for(var key in newParams) {
      // Get new param value
      var value = newParams[key];
      // Check if value exists
      if( !value || value == undefined || value == 'undefined' ) continue;
      // Replace '-' with '_' in key
      var urlSafeKey = key.replace(/-/g, '_');
      // Check if key exists
      if( !urlSafeKey ) continue;
      // Replace key with value in params
      params[urlSafeKey] = value;
    }

    // Create an array from params,
    // and url encode the values
    for(var key in params) {
      if (params.hasOwnProperty(key)) {
        var value = params[key];
        // Check if value exists
        if( !value ) continue;
        // Url encode both key and value, join them with '=' and then add to new array,
        // which will be used to create a query string
        var urlEncodedKey = encodeURIComponent(key);
        var urlEncodedValue = encodeURIComponent(value);
        // Replace all '%20' and '%2B' values in param with a '+' symbol
        var valueWithPlusSeperatedString = urlEncodedValue.replace(/(%2B|%20)/g, '+');
        // Push the current key/value param to an array as as string,
        // seperated with a equal sign
        paramsArray.push(urlEncodedKey + "=" + valueWithPlusSeperatedString);
      }
    }

    // Create query string from params array 
    paramsString = paramsArray.join("&");

    // Create new url based on old seperated url,
    // delimited with '&'
    newURL = seperatedURL[0] + '?' + paramsString;

    // Return the new url,
    // with updated query string params
    return newURL;

  }

})(document);