public override IEnumerable <object> ConvertTokens(IEnumerable <object> sequence)
{
var result = new List <object>();
bool foundBlockParams = false;
foreach (var item in sequence)
{
if (item is BlockParameterToken blockParameterToken)
{
if (foundBlockParams)
{
throw new HandlebarsCompilerException("multiple blockParams expressions are not supported");
}
foundBlockParams = true;
if (!(result.Last() is PathExpression pathExpression))
{
throw new HandlebarsCompilerException("blockParams definition has incorrect syntax");
}
if (!string.Equals("as", pathExpression.Path, StringComparison.OrdinalIgnoreCase))
{
throw new HandlebarsCompilerException("blockParams definition has incorrect syntax");
}
result[result.Count - 1] = HandlebarsExpression.BlockParams(pathExpression.Path, blockParameterToken.Value);
}
else
{
result.Add(item);
}
}
return(result);
}
public override IEnumerable <object> ConvertTokens(IEnumerable <object> sequence)
{
var enumerator = sequence.GetEnumerator();
while (enumerator.MoveNext())
{
var item = enumerator.Current;
if (item is StartExpressionToken)
{
yield return(item);
item = GetNext(enumerator);
if (item is Expression)
{
yield return(item);
continue;
}
var word = item as WordExpressionToken;
if (word != null && IsRegisteredHelperName(word.Value))
{
yield return(HandlebarsExpression.Helper(word.Value));
}
else
{
yield return(item);
}
}
else
{
yield return(item);
}
}
}
public ConditionalBlockAccumulatorContext(Expression startingNode)
: base(startingNode)
{
startingNode = UnwrapStatement(startingNode);
var helperExpression = (HelperExpression)startingNode;
var testType = helperExpression.HelperName[0] == '#' ? TestType.Direct : TestType.Reverse;
BlockName = helperExpression.HelperName.Substring(1, helperExpression.HelperName.Length - 1);
if (!ValidHelperNames.Contains(BlockName))
{
throw new HandlebarsCompilerException($"Tried to convert {BlockName} expression to conditional block", helperExpression.Context);
}
var argument = HandlebarsExpression.Boolish(helperExpression.Arguments.Single());
_currentCondition = BlockName switch
{
"if" when testType == TestType.Direct => argument,
"if" when testType == TestType.Reverse => Expression.Not(argument),
"unless" when testType == TestType.Direct => Expression.Not(argument),
"unless" when testType == TestType.Reverse => argument,
_ => throw new HandlebarsCompilerException($"Tried to convert {BlockName} expression to conditional block", helperExpression.Context)
};
}
public override IEnumerable <object> ConvertTokens(IEnumerable <object> sequence)
{
var enumerator = sequence.GetEnumerator();
while (enumerator.MoveNext())
{
var item = enumerator.Current;
if (item is HashParameterToken)
{
var parameters = AccumulateParameters(enumerator);
if (parameters.Any())
{
yield return(HandlebarsExpression.HashParametersExpression(parameters));
}
yield return(enumerator.Current);
}
else
{
yield return(item);
}
}
}
public override IEnumerable <object> ConvertTokens(IEnumerable <object> sequence)
{
var enumerator = sequence.GetEnumerator();
while (enumerator.MoveNext())
{
var item = enumerator.Current;
if (item is HashParameterAssignmentExpression parameterAssignment)
{
bool moveNext;
var parameters = AccumulateParameters(enumerator, out moveNext);
if (parameters.Any())
{
yield return(HandlebarsExpression.HashParametersExpression(parameters));
}
if (!moveNext)
{
yield break;
}
item = enumerator.Current;
}
yield return(item is Expression expression?Visit(expression) : item);
}
}
public override bool IsClosingElement(Expression item)
{
if (IsClosingNode(item))
{
// If the template has no content within the block, e.g. `{{#each ...}}{{/each}`, then the block body is a no-op.
var bodyStatements = _body.Count != 0 ? _body : new List <Expression> {
Expression.Empty()
};
if (_accumulatedExpression == null)
{
_accumulatedExpression = HandlebarsExpression.Iterator(
_startingNode.Arguments.Single(),
Expression.Block(bodyStatements));
}
else
{
_accumulatedExpression = HandlebarsExpression.Iterator(
((IteratorExpression)_accumulatedExpression).Sequence,
((IteratorExpression)_accumulatedExpression).Template,
Expression.Block(bodyStatements));
}
return(true);
}
else
{
return(false);
}
}
public override IEnumerable <object> ConvertTokens(IEnumerable <object> sequence)
{
var enumerator = sequence.GetEnumerator();
while (enumerator.MoveNext())
{
var item = enumerator.Current;
while (item is WordExpressionToken word)
{
item = GetNext(enumerator);
if (item is AssignmentToken)
{
yield return(HandlebarsExpression.HashParameterAssignmentExpression(word.Value));
item = GetNext(enumerator);
}
else
{
yield return(word);
}
}
yield return(item);
}
}
Expression Visit(Expression expression)
{
if (expression is HelperExpression helperExpression)
{
var originalArguments = helperExpression.Arguments.ToArray();
var arguments = ConvertTokens(originalArguments)
.Cast <Expression>()
.ToArray();
if (!arguments.SequenceEqual(originalArguments))
{
return(HandlebarsExpression.Helper(
helperExpression.HelperName,
arguments,
helperExpression.IsRaw));
}
}
if (expression is SubExpressionExpression subExpression)
{
Expression childExpression = Visit(subExpression.Expression);
if (childExpression != subExpression.Expression)
{
return(HandlebarsExpression.SubExpression(childExpression));
}
}
return(expression);
}
public override Expression GetAccumulatedBlock()
{
return(HandlebarsExpression.Partial(
_startingNode.PartialName,
_startingNode.Argument,
_body.Count > 1 ? Expression.Block(_body) : _body.First()));
}
private PartialExpression ConvertToPartialExpression(Expression expression)
{
if (expression is PathExpression)
{
var pathExpression = (PathExpression)expression;
_blockName = pathExpression.Path.Replace("#>", "");
return(HandlebarsExpression.Partial(Expression.Constant(_blockName)));
}
else if (expression is HelperExpression)
{
var helperExpression = (HelperExpression)expression;
_blockName = helperExpression.HelperName.Replace("#>", "");
if (helperExpression.Arguments.Count() == 0)
{
return(HandlebarsExpression.Partial(Expression.Constant(_blockName)));
}
else if (helperExpression.Arguments.Count() == 1)
{
return(HandlebarsExpression.Partial(
Expression.Constant(_blockName),
helperExpression.Arguments.First()));
}
else
{
throw new InvalidOperationException("Cannot convert a multi-argument helper expression to a partial expression");
}
}
else
{
throw new InvalidOperationException(string.Format("Cannot convert '{0}' to a partial expression", expression));
}
}
public override Expression GetAccumulatedBlock()
{
if (_accumulatedBody == null)
{
_accumulatedBody = GetBlockBody();
_accumulatedInversion = Expression.Block(Expression.Empty());
}
else if (_accumulatedInversion == null)
{
_accumulatedInversion = GetBlockBody();
}
var resultExpr = HandlebarsExpression.BlockHelper(
_startingNode.HelperName,
_startingNode.Arguments.Where(o => o.NodeType != (ExpressionType)HandlebarsExpressionType.BlockParamsExpression),
_startingNode.Arguments.OfType <BlockParamsExpression>().SingleOrDefault() ?? BlockParamsExpression.Empty(),
_accumulatedBody,
_accumulatedInversion,
_startingNode.IsRaw);
if (_startingNode.IsRaw)
{
return(HandlebarsExpression.Statement(
resultExpr,
false,
_trimBefore,
_trimAfter));
}
return(resultExpr);
}
public override Expression GetAccumulatedBlock()
{
if (_accumulatedBody == null)
{
_accumulatedBody = GetBlockBody();
_accumulatedInversion = Expression.Block(Expression.Empty());
}
else if (_accumulatedInversion == null)
{
_accumulatedInversion = GetBlockBody();
}
var resultExpr = HandlebarsExpression.BlockHelper(
_startingNode.HelperName,
_startingNode.Arguments,
_accumulatedBody,
_accumulatedInversion,
_startingNode.IsRaw);
if (_startingNode.IsRaw)
{
return(HandlebarsExpression.Statement(
resultExpr,
false,
_trimBefore,
_trimAfter));
}
return(resultExpr);
}
public override IEnumerable <object> ConvertTokens(IEnumerable <object> sequence)
{
var enumerator = sequence.GetEnumerator();
while (enumerator.MoveNext())
{
var item = enumerator.Current;
var partialToken = item as PartialToken;
if (partialToken != null)
{
var partialName = partialToken.Value.Substring(1).Trim('"');
var arguments = AccumulateArguments(enumerator);
if (arguments.Count == 0)
{
yield return(HandlebarsExpression.Partial(partialName));
}
else if (arguments.Count == 1)
{
yield return(HandlebarsExpression.Partial(partialName, arguments[0]));
}
else
{
throw new HandlebarsCompilerException(string.Format("Partial {0} can only accept 0 or 1 arguments", partialName));
}
yield return(enumerator.Current);
}
else
{
yield return(item);
}
}
}
protected override Expression VisitBlockHelperExpression(BlockHelperExpression bhex)
{
return(HandlebarsExpression.BlockHelper(
bhex.HelperName,
bhex.Arguments.Select(arg => Visit(arg)),
Visit(bhex.Body),
Visit(bhex.Inversion)));
}
protected virtual Expression VisitStatementExpression(StatementExpression sex)
{
Expression body = Visit(sex.Body);
if (body != sex.Body)
{
return(HandlebarsExpression.Statement(body, sex.IsEscaped, sex.TrimBefore, sex.TrimAfter));
}
return(sex);
}
protected virtual Expression VisitHelperExpression(HelperExpression hex)
{
var arguments = VisitExpressionList(hex.Arguments);
if (arguments != hex.Arguments)
{
return(HandlebarsExpression.Helper(hex.HelperName, hex.IsBlock, arguments, hex.IsRaw));
}
return(hex);
}
protected virtual Expression VisitBoolishExpression(BoolishExpression bex)
{
Expression condition = Visit(bex.Condition);
if (condition != bex.Condition)
{
return(HandlebarsExpression.Boolish(condition));
}
return(bex);
}
protected virtual Expression VisitSubExpression(SubExpressionExpression subex)
{
Expression expression = Visit(subex.Expression);
if (expression != subex.Expression)
{
return(HandlebarsExpression.SubExpression(expression));
}
return(subex);
}
protected override Expression VisitDeferredSectionExpression(DeferredSectionExpression dsex)
{
var method = new Action <object, BindingContext, Action <TextWriter, object>, Action <TextWriter, object> >(RenderSection).Method;
Expression path = HandlebarsExpression.Path(dsex.Path.Path.Substring(1));
Expression context = CompilationContext.BindingContext;
Expression[] templates = GetDeferredSectionTemplates(dsex);
return(Expression.Call(method, new[] { path, context }.Concat(templates)));
}
protected virtual Expression VisitDeferredSectionExpression(DeferredSectionExpression dsex)
{
PathExpression path = (PathExpression)Visit(dsex.Path);
// Don't visit Body/Inversion - they will be compiled separately
if (path != dsex.Path)
{
return(HandlebarsExpression.DeferredSection(path, dsex.Body, dsex.Inversion));
}
return(dsex);
}
public override IEnumerable <object> ConvertTokens(IEnumerable <object> sequence)
{
var enumerator = sequence.GetEnumerator();
while (enumerator.MoveNext())
{
var item = enumerator.Current;
if (!(item is StartExpressionToken token))
{
yield return(item);
continue;
}
var isRaw = token.IsRaw;
yield return(token);
item = GetNext(enumerator);
switch (item)
{
case Expression _:
yield return(item);
continue;
case WordExpressionToken word when IsRegisteredHelperName(word.Value):
yield return(HandlebarsExpression.Helper(word.Value, false, isRaw, word.Context));
break;
case WordExpressionToken word when IsRegisteredBlockHelperName(word.Value, isRaw):
{
yield return(HandlebarsExpression.Helper(word.Value, true, isRaw, word.Context));
break;
}
case WordExpressionToken word when IsUnregisteredBlockHelperName(word.Value, isRaw, sequence):
{
var expression = HandlebarsExpression.Helper(word.Value, true, isRaw, word.Context);
expression.IsBlock = true;
yield return(expression);
break;
}
default:
yield return(item);
break;
}
}
}
protected virtual Expression VisitIteratorExpression(IteratorExpression iex)
{
Expression sequence = Visit(iex.Sequence);
// Don't visit Template/IfEmpty - they will be compiled separately
if (sequence != iex.Sequence)
{
return(HandlebarsExpression.Iterator(sequence, iex.BlockParams, iex.Template, iex.IfEmpty));
}
return(iex);
}
protected virtual Expression VisitBlockHelperExpression(BlockHelperExpression bhex)
{
var arguments = VisitExpressionList(bhex.Arguments);
// Don't visit Body/Inversion - they will be compiled separately
if (arguments != bhex.Arguments)
{
return(HandlebarsExpression.BlockHelper(bhex.HelperName, arguments, bhex.BlockParams, bhex.Body, bhex.Inversion, bhex.IsRaw));
}
return(bhex);
}
public override IEnumerable <object> ConvertTokens(IEnumerable <object> sequence)
{
var enumerator = sequence.GetEnumerator();
while (enumerator.MoveNext())
{
var item = enumerator.Current;
switch (item)
{
case HelperExpression helper:
{
var helperArguments = AccumulateArguments(enumerator);
yield return(HandlebarsExpression.Helper(
helper.HelperName,
helper.IsBlock,
helperArguments,
helper.IsRaw));
yield return(enumerator.Current);
break;
}
case PathExpression path:
{
var helperArguments = AccumulateArguments(enumerator);
if (helperArguments.Count > 0)
{
yield return(HandlebarsExpression.Helper(
path.Path,
false,
helperArguments,
((EndExpressionToken)enumerator.Current)?.IsRaw ?? false));
yield return(enumerator.Current);
}
else
{
yield return(path);
yield return(enumerator.Current);
}
break;
}
default:
yield return(item);
break;
}
}
}
private static object Convert(object item)
{
if (item is CommentToken commentToken)
{
return(HandlebarsExpression.Comment(commentToken.Value));
}
if (item is LayoutToken)
{
return(HandlebarsExpression.Comment(null));
}
return(item);
}
protected virtual Expression VisitPartialExpression(PartialExpression pex)
{
Expression partialName = Visit(pex.PartialName);
Expression argument = Visit(pex.Argument);
// Don't visit Fallback - it will be compiled separately
if (partialName != pex.PartialName ||
argument != pex.Argument)
{
return(HandlebarsExpression.Partial(partialName, argument, pex.Fallback));
}
return(pex);
}
public override void HandleElement(Expression item)
{
if (IsElseBlock(item))
{
_accumulatedExpression = HandlebarsExpression.Iterator(
_startingNode.Arguments.Single(),
Expression.Block(_body));
_body = new List <Expression>();
}
else
{
_body.Add((Expression)item);
}
}
public override IEnumerable <object> ConvertTokens(IEnumerable <object> sequence)
{
foreach (var item in sequence)
{
if (item is WordExpressionToken wordExpressionToken)
{
yield return(HandlebarsExpression.Path(wordExpressionToken.Value));
}
else
{
yield return(item);
}
}
}
public override void HandleElement(Expression item)
{
if (IsElseBlock(item))
{
_accumulatedExpression = HandlebarsExpression.Iterator(
_startingNode.Arguments.Single(o => o.NodeType != (ExpressionType)HandlebarsExpressionType.BlockParamsExpression),
_startingNode.Arguments.OfType <BlockParamsExpression>().SingleOrDefault() ?? BlockParamsExpression.Empty(),
Expression.Block(_body));
_body = new List <Expression>();
}
else
{
_body.Add((Expression)item);
}
}
public ConditionalBlockAccumulatorContext(Expression startingNode)
: base(startingNode)
{
startingNode = UnwrapStatement(startingNode);
_blockName = ((HelperExpression)startingNode).HelperName.Replace("#", "");
if (new [] { "if", "unless" }.Contains(_blockName) == false)
{
throw new HandlebarsCompilerException(string.Format(
"Tried to convert {0} expression to conditional block", _blockName));
}
_testType = _blockName == "if";
var argument = HandlebarsExpression.Boolish(((HelperExpression)startingNode).Arguments.Single());
_currentCondition = _testType ? (Expression)argument : Expression.Not(argument);
}
