Preconditions:

  • Enable Rating with Stars in a List.
  • Prepare some sort of HTML to show list item Information. Add a div which will act as the Container for the Rating Control.

Script:

In your script preload the needed dependencies:
SP.SOD.executeOrDelayUntilScriptLoaded(function() {
 SP.SOD.executeOrDelayUntilScriptLoaded(function() {
 SP.SOD.registerSod("sp.ui.reputation.js", SP.Utilities.Utility.getLayoutsPageUrl("sp.ui.reputation.js"));
 SP.SOD.executeOrDelayUntilScriptLoaded(function() {
 SP.SOD.executeFunc("sp.ui.reputation.js", "SP.UI.Reputation.AverageRatingFieldTemplate", contoso.collaboration.start);
 },
 "clienttemplates.js");
 SP.SOD.executeFunc("clienttemplates.js", false, function() {});
 },
 "sp.js");
 SP.SOD.executeFunc("sp.js", false, function() {});
},
"strings.js");

In your start function get a List-Item and call the function renderAverageControl.

contoso.collaboration.start = function()
{
 var clientContext = SP.ClientContext.get_current();
 
 if (clientContext) {
 var oList = clientContext.get_web().get_lists().getByTitle('<a list title>'); 
 var item = oList.getItemById(<a listem item id>);
  
 clientContext.load(item);
 clientContext.executeQueryAsync(
 function () {
 if (item) {
 var id = item.get_id();
 var averageRating = item.get_item('AverageRating'); 
 var ratingCount = item.get_item('RatingCount');
 var _RatedBy = item.get_item("RatedBy");
 contoso.collaboration.renderAverageControl(_RatedBy, "averageRatingDiv", averageRating, ratingCount, id);
 }
 },
 function (sender, args) {
 if(args)
 {
 console.log("Request to get ... failed. " + '\n' + args.get_message() + '\n' + args.get_stackTrace());
  }
 alert("Sorry something went wrong!");
 });
 }
}

The function renderAverageControl:

contoso.collaboration.renderAverageControl = function(_RatedBy, containerId, averageRating, ratingCount, itemId)
{
 var average = { container: undefined};
 average.container = document.getElementById(containerId);
 
 var ratedByLookupItems = _RatedBy;
 var ratedBy = [];
 if (ratedByLookupItems != null) {
 for (var i = 0; i < ratedByLookupItems.length; i++) {
 var ratedByItem = ratedByLookupItems[i];
 ratedBy[ratedBy.length] = {
 id: String(ratedByItem.get_lookupId())
 , value: ratedByItem.get_lookupValue()
 , title: ratedByItem.get_lookupValue()
 };
 }
 }
  
 var displayContext = new Context();
 displayContext.CurrentItem = [];
 displayContext.CurrentItem.ID = itemId;
 displayContext.CurrentItem.AverageRating = averageRating === null?"0":averageRating.toString();
 displayContext.CurrentItem.Ratings = ratingCount === null?"0":ratingCount.toString().replace(".",",");
 displayContext.CurrentItem.RatedBy = ratedBy;
 displayContext.listName = "{EE87F0D6-832A-4E45-9A80-A3EA3990A3D3}";
 displayContext.listTemplate = g_wsaListTemplateId;
 displayContext.CurrentItem.ContentTypeId = "0x0100CBDF088C26134A2D9AB8508476DB1B12";
 displayContext.CurrentItem.FSObjType = "0";
 displayContext.HttpRoot = _spPageContextInfo.siteAbsoluteUrl;
 displayContext.ListSchema = {
 Userid: _spPageContextInfo.userId,
 Direction: "LTR"
 };
 
 displayContext.CurrentFieldSchema = {
 AllowGridEditing: "FALSE",
 GridActiveAndReadOnly: "TRUE",
 fieldRenderer: SP.UI.Reputation.AverageRatingFieldTemplate.renderAverageRatingField
 };
 average.container.innerHTML = SP.UI.Reputation.AverageRatingFieldTemplate.renderAverageRatingField(displayContext);
 
 SP.UI.Reputation.AverageRatingFieldTemplate.onPostRender();
}

Important note

  • displayContext.listName must be the GUID of the list. If you use the list Name you will get an error when you rate an item.
  • displayContext.CurrentItem.ContentTypeId should be the ContentTypeId of the list. It does not matter if you use list Content type or its parent.
  • displayContext.CurrentItem.AverageRating: You have to avoid null. Value has to be a string otherwise, you will get an error because a trim() of the value will fail in a SharePoint JavaScript file.
  • displayContext.CurrentItem.Ratings: same as to AverageRating.
  • onPostRender will add the Event handler so that a user can rate by click from the start.

This snippet has been used based on a custom list and custom Content type.