public void It_Should_Find_Elements_In_Its_Array()
{
// Arrange
var cycleTag = new CycleTag();
cycleTag.CycleList.Add(new TreeNode<LiquidExpression>(new LiquidExpression { Expression = new StringValue("A")}));
cycleTag.CycleList.Add(new TreeNode<LiquidExpression>(new LiquidExpression { Expression = new StringValue("B") }));
cycleTag.CycleList.Add(new TreeNode<LiquidExpression>(new LiquidExpression { Expression = new StringValue("C") }));
// Assert
Assert.That(((StringValue) cycleTag.ElementAt(0).Data.Expression).StringVal, Is.EqualTo("A"));
Assert.That(((StringValue) cycleTag.ElementAt(1).Data.Expression).StringVal, Is.EqualTo("B"));
}
/// <summary>
/// Side effect: state is managed in the _counters dictionary.
/// </summary>
/// <returns></returns>
private String GetNextCycleText(String groupName, CycleTag cycleTag)
{
int currentIndex;
// Create a like dictionary key entry to keep track of this declaration. THis takes the variable
// names (not the eval-ed variables) or literals and concatenates them together.
var key = "cycle_" + groupName + "_" + String.Join("|", cycleTag.CycleList.Select(x => x.Data.Expression.ToString()));
while (true)
{
currentIndex = _counters.GetOrAdd(key, 0);
var newindex = (currentIndex + 1) % cycleTag.Length;
// fails if updated concurrently by someone else.
if (_counters.TryUpdate(key, newindex, currentIndex))
{
break;
}
}
String result = "";
var currentElement = cycleTag.ElementAt(currentIndex);
LiquidExpressionEvaluator.Eval(currentElement, _templateContext)
.WhenSuccess(x => result = ValueCaster.RenderAsString(LiquidExpressionEvaluator.Eval(currentElement, _templateContext).SuccessResult.Value))
.WhenError(err => result = FormatErrors(new List<LiquidError> {err}));
return result;
}
public void Visit(CycleTag cycleTag)
{
_result += cycleTag.ToString();
}
public void Visit(CycleTag cycleTag)
{
String groupName = null;
if (cycleTag.GroupNameExpressionTree != null)
{
LiquidError error = null;
// figure out the group name if any, otherwise use null.
LiquidExpressionEvaluator.Eval(cycleTag.GroupNameExpressionTree, _templateContext)
.WhenSuccess(x => groupName = x.HasValue ? ValueCaster.RenderAsString(x.Value) : null)
.WhenError(x => error = x);
if (error!=null)
{
RenderError(error);
return;
}
}
AppendTextToCurrentAccumulator(GetNextCycleText(groupName, cycleTag));
}