Here is a simple wrapper function I created for use with the SharePoint Rest API. If an Id is entered the function will update a record, otherwise it will insert a new record.

Usage:
[SyntaxHLNumbers]
//Create ListItem Object
var customers = {};
//Set List Name
customers._listName = “Customers”;
//Add columns to insert
customers.Name = “Michael Tippett”;
customers.Email = “My@email.com”;
//Insert into SharePoint
SpproJsFramework.listItem.upsert(customers, successDelegate, errorDelegate);
[/SyntaxHLNumbers]

Under the hood:
[SyntaxHLNumbers]
var SpproJsFramework {
listItem: {
upsert: function(listObject, success, failure) {
var itemType = this.GetItemTypeForListName(listObject.listName); //Insert URL var url = _spPageContextInfo.siteAbsoluteUrl + “/_api/web/lists/getbytitle(‘” + listObject._listName + “‘)/items”; if (listObject.Id) { //Update not Insert url = _spPageContextInfo.siteAbsoluteUrl + “/_api/web/lists/getbytitle(‘” + listObject._listName + “‘)/items(” + listObject.Id + “)”; } var item = { “__metadata”: { “type”: itemType } }; //Add properties to rest object for (var key in listObject) { if (key.charAt(0) != ““) {
item[key] = listObject[key];
}
}
var headers = {
“Accept”: “application/json;odata=verbose”,
“X-RequestDigest”: $(“#_REQUESTDIGEST”).val(), }; if (listObject.Id) { //Update (Merge) headers headers = { “Accept”: “application/json;odata=verbose”, “content-type”: “application/json; odata=verbose”, “X-RequestDigest”: $(“#__REQUESTDIGEST”).val(), “X-HTTP-Method”: “MERGE”, “If-Match”: “*” } } $.ajax({ url: url, type: “POST”, contentType: “application/json;odata=verbose”, data: JSON.stringify(item), headers: headers, success: function(data) { success(data); }, error: function(data) { failure(data); } }); }, GetItemTypeForListName: function(name) { return “SP.Data.” + name.charAt(0).toUpperCase() + name.split(” “).join(“_x0020“).slice(1) + “ListItem”;
}
}
}
[/SyntaxHLNumbers]