public DjangoFilter(string filterName, int filterStart, DjangoVariableValue arg = null, int groupStart = 0)
{
Filter = filterName;
FilterStart = filterStart;
ArgStart = groupStart;
Arg = arg;
}
private static DjangoFilter GetFilterFromMatch(Match match, int start)
{
var filterName = match.Groups["filter_name"];
if (!filterName.Success)
{
// TODO: Report error
}
var filterStart = filterName.Index;
DjangoVariableValue arg = null;
int argStart = 0;
var constantGroup = match.Groups["constant_arg"];
if (constantGroup.Success)
{
arg = new DjangoVariableValue(constantGroup.Value, DjangoVariableKind.Constant);
argStart = constantGroup.Index;
}
else
{
var varGroup = match.Groups["var_arg"];
if (varGroup.Success)
{
arg = new DjangoVariableValue(varGroup.Value, DjangoVariableKind.Variable);
argStart = varGroup.Index;
}
else
{
var numGroup = match.Groups["num_arg"];
if (numGroup.Success)
{
arg = new DjangoVariableValue(numGroup.Value, DjangoVariableKind.Number);
argStart = numGroup.Index;
}
}
}
return(new DjangoFilter(filterName.Value, filterStart + start, arg, argStart + start));
}
public static DjangoVariable Parse(string filterText, int start = 0)
{
if (filterText.StartsWithOrdinal("{{"))
{
filterText = GetTrimmedFilterText(filterText, ref start);
if (filterText == null)
{
return(null);
}
}
else
{
int i = 0;
while (i < filterText.Length && char.IsWhiteSpace(filterText[i]))
{
++i;
++start;
}
if (i < filterText.Length)
{
filterText = filterText.Substring(i).TrimEnd();
}
}
int varStart = start;
DjangoVariableValue variable = null;
List <DjangoFilter> filters = new List <DjangoFilter>();
foreach (Match match in _filterRegex.Matches(filterText))
{
if (variable == null)
{
var constantGroup = match.Groups["constant"];
if (constantGroup.Success)
{
varStart = constantGroup.Index;
variable = new DjangoVariableValue(constantGroup.Value, DjangoVariableKind.Constant);
}
else
{
var varGroup = match.Groups["var"];
if (!varGroup.Success)
{
var numGroup = match.Groups["num"];
if (!numGroup.Success)
{
return(null);
}
varStart = numGroup.Index;
variable = new DjangoVariableValue(numGroup.Value, DjangoVariableKind.Number);
}
else
{
varStart = varGroup.Index;
variable = new DjangoVariableValue(varGroup.Value, DjangoVariableKind.Variable);
}
}
}
else
{
filters.Add(GetFilterFromMatch(match, start));
}
}
return(new DjangoVariable(variable, varStart + start, filters.ToArray()));
}
public DjangoVariable(DjangoVariableValue expression, int expressionStart, params DjangoFilter[] filters)
{
Expression = expression;
ExpressionStart = expressionStart;
Filters = filters;
}
