public static LiquidExpressionResult Eval(
LiquidExpression expression,
IEnumerable <Option <ILiquidValue> > leaves,
ITemplateContext templateContext)
{
// calculate the first part of the expression
var objResult = expression.Expression == null?
LiquidExpressionResult.Success(new None <ILiquidValue>()) :
expression.Expression.Eval(templateContext, leaves);
if (objResult.IsError)
{
return(objResult);
}
// Compose a chain of filters, making sure type-casting
// is done between them.
//IEnumerable<Tuple<FilterSymbol, IFilterExpression>> filterExpressionTuples;
// try
// {
var filterExpressionTuples = expression.FilterSymbols.Select(symbol =>
new Tuple <FilterSymbol, Try <IFilterExpression> >(symbol, InstantiateFilter(templateContext, symbol)))
.ToList();
//}
//catch (Exception ex)
//{
// return LiquidExpressionResult.Error(ex.Message);
//}
if (filterExpressionTuples.Any(x => x.Item2.IsFailure))
{
// just return the first error.
return(LiquidExpressionResult.Error(filterExpressionTuples.First().Item2.Exception.Message));
}
var erroringFilternames = filterExpressionTuples.Where(x => x.Item2 == null).Select(x => x.Item1).ToList();
if (erroringFilternames.Any())
{
//throw new Exception("Missing filters...");
//return ConstantFactory.CreateError<LiquidString>();
return(LiquidExpressionResult.Error("Missing filters: " + String.Join(", ", erroringFilternames.Select(x => x.Name))));
}
var filterChain = FilterChain.CreateChain(
objResult.GetType(),
templateContext,
filterExpressionTuples.Select(x => x.Item2.Value));
// apply the composed function to the object
var result = filterChain(objResult.SuccessResult);
return(result);
}
public void It_Should_Compose_Functions_Together()
{
// Arrange
var removeFilter = new RemoveFilter(LiquidString.Create("123"));
var upCase = new UpCaseFilter();
var filterList = new List <IFilterExpression> {
removeFilter, upCase
};
var compositeFilterFn = FilterChain.CreateChain(new TemplateContext(), filterList);
// Act
var result = compositeFilterFn(LiquidString.Create("test123")).SuccessValue <LiquidString>();
// Assert
Assert.That(result.Value, Is.EqualTo("TEST"));
}
