使用匿名函数javascript，Sharepoint的返回值

Question

我想获得res2的返回值true或false，并在最后一次返回时使用它。因此它可以像PreSaveAction上的第一个验证一样验证demoField值。

＆＃13;

＆＃13;

function ViewItem(listTitle, Success, Error) {
	var context = new SP.ClientContext.get_current();
	var web = context.get_web();
	var list = web.get_lists().getByTitle(listTitle);
	var query = SP.CamlQuery.createAllItemsQuery();
	var allItems = list.getItems(query);
	context.load(allItems, 'Include(Title, EventDate, tiempo2)');
	context.executeQueryAsync(function(){
			var currentTitle = SPUtility.GetSPFieldByInternalName('EventDate').GetValue();
			var res = "No";
			for (var i = 0; i < allItems.get_count(); i++) {
				var item = allItems.get_item(i);
				console.log(item.get_item('tiempo2') + ' - ' + currentTitle );
				if (currentTitle == item.get_item('tiempo2')){
					res = "Si"; 
					console.log('There is an event with the same Start Date on DemoTrainingRoom2' 
						+ ' ' + item.get_item('tiempo2') + ' - ' + currentTitle);
            		
        		}
			}
			return Success(res);
		},
		Error
	);
}

function PreSaveAction() {
	var time = SPUtility.GetSPFieldByInternalName('EventDate').GetValue();
	alert(time + " Current Start Time ");
	
	if(SPUtility.GetSPField('demoField').GetValue() == "no") {
		alert('No need for validation');
		return true;
	} 
	else if(SPUtility.GetSPField('demoField').GetValue() == "yes") {
		
		var res2 = ViewItem('demoTrainingRoom2', function(res){
				console.log('Result: ' + res);
				if(res == "Si") 
				{
					alert(res);
					return false; //I want this or
				}
				else
				{
					alert(res); 
					return true; // This
				}		
			},
			function (sender, args) {
				alert("failed. Message:" + args.get_message());
			}
		)
		;
		return res2; // Over here
	}
}

＆＃13;

＆＃13;

＆＃13;