This method is used to get information from a SharePoint list. As parameter, it receives a JavaScript object with two properties: the GUID of the SharePoint list and the URL to the SharePoint site containing that list.
You can use List.getListMetadata to get valuable information from a list before adding or updating an item to that list. For example, you get the content types and required fields from the list. In the case that you need the GUID of the list, you can get it using the Web.getWebsAndLists method.
SPlus.List.getListMetadata (args, function (result){
//TODO: Implement what to do with the list information
}, function (eResponse){
//TODO: Implement how to handle error information
}, function (){
//TODO: Implement how to handle a user’s cancel
});