private void AddHistoryEntry(string content, string expression)
{
if (HistoryItems.Count > 0)
{
// check to see if the content has changed
var lastEntry = HistoryItems[0];
if (lastEntry.ResourceContent == content && lastEntry.Expression == expression)
{
return; // (no need to add a new entry)
}
}
HistoryItems.Insert(0, new HistoryItemDetails(content, expression));
// trim the history to only 100 items
while (HistoryItems.Count > 100)
{
HistoryItems.Remove(HistoryItems.Last());
}
}