/// <summary>
/// Parse the template, and capture paths used in the template to determine a suitable structure for the required model.
/// </summary>
/// <param name="templateSource">The template content to parse.</param>
/// <param name="disableContentEscaping">In some cases, content should not be escaped (such as when rendering text bodies and subjects in emails).
/// By default, we use content escaping, but this parameter allows it to be disabled.</param>
/// <returns></returns>
public static ExtendedParseInformation ParseWithModelInference(string templateSource, bool disableContentEscaping = false)
{
var tokens = new Queue<TokenPair>(Tokenizer.Tokenize(templateSource));
var options = new ParsingOptions { DisableContentSafety = disableContentEscaping };
var inferredModel = new InferredTemplateModel();
var internalTemplate = Parse(tokens, options, inferredModel);
Func<IDictionary<String, object>, String> template = (model) =>
{
var retval = new StringBuilder();
var context = new ContextObject()
{
Value = model,
Key = ""
};
internalTemplate(retval, context);
return retval.ToString();
};
var result = new ExtendedParseInformation()
{
InferredModel = inferredModel,
ParsedTemplate = template
};
return result;
}
private static Action<StringBuilder, ContextObject> HandleCollectionOpen(TokenPair token, Queue<TokenPair> remainder, ParsingOptions options, InferredTemplateModel scope)
{
if (scope != null)
{
scope = scope.GetInferredModelForPath(token.Value, InferredTemplateModel.UsedAs.Collection);
}
var innerTemplate = Parse(remainder, options, scope);
return (builder, context) =>
{
//if we're in the same scope, just negating, then we want to use the same object
var c = context.GetContextForPath(token.Value);
//"falsey" values by Javascript standards...
if (!c.Exists()) return;
if (c.Value is IEnumerable && !(c.Value is String) && !(c.Value is IDictionary<string, object>))
{
var index = 0;
foreach (object i in c.Value as IEnumerable)
{
var innerContext = new ContextObject()
{
Value = i,
Key = String.Format("[{0}]", index),
Parent = c
};
innerTemplate(builder, innerContext);
index++;
}
}
else
{
throw new IndexedParseException("'{0}' is used like an array by the template, but is a scalar value or object in your model.", token.Value);
}
};
}
private static Action<StringBuilder, ContextObject> Parse(Queue<TokenPair> tokens, ParsingOptions options, InferredTemplateModel currentScope = null)
{
var buildArray = new List<Action<StringBuilder, ContextObject>>();
while (tokens.Any())
{
var currentToken = tokens.Dequeue();
switch (currentToken.Type)
{
case TokenType.Comment:
break;
case TokenType.Content:
buildArray.Add(HandleContent(currentToken.Value));
break;
case TokenType.CollectionOpen:
buildArray.Add(HandleCollectionOpen(currentToken, tokens, options, currentScope));
break;
case TokenType.ElementOpen:
buildArray.Add(HandleElementOpen(currentToken, tokens, options, currentScope));
break;
case TokenType.InvertedElementOpen:
buildArray.Add(HandleInvertedElementOpen(currentToken, tokens, options, currentScope));
break;
case TokenType.CollectionClose:
case TokenType.ElementClose:
// This should immediately return if we're in the element scope,
// and if we're not, this should have been detected by the tokenizer!
return (builder, context) =>
{
foreach (var a in buildArray)
{
a(builder, context);
}
};
case TokenType.EscapedSingleValue:
case TokenType.UnescapedSingleValue:
buildArray.Add(HandleSingleValue(currentToken, options, currentScope));
break;
}
}
return (builder, context) =>
{
foreach (var a in buildArray)
{
a(builder, context);
}
};
}
private static Action<StringBuilder, ContextObject> HandleInvertedElementOpen(TokenPair token, Queue<TokenPair> remainder,
ParsingOptions options, InferredTemplateModel scope)
{
if (scope != null)
{
scope = scope.GetInferredModelForPath(token.Value, InferredTemplateModel.UsedAs.ConditionalValue);
}
var innerTemplate = Parse(remainder, options, scope);
return (builder, context) =>
{
var c = context.GetContextForPath(token.Value);
//"falsey" values by Javascript standards...
if (!c.Exists())
{
innerTemplate(builder, c);
}
};
}
private static Action<StringBuilder, ContextObject> HandleSingleValue(TokenPair token, ParsingOptions options, InferredTemplateModel scope )
{
if (scope != null)
{
scope = scope.GetInferredModelForPath(token.Value, InferredTemplateModel.UsedAs.Scalar);
}
return (builder, context) =>
{
if (context != null)
{
//try to locate the value in the context, if it exists, append it.
var c = context.GetContextForPath(token.Value);
if (c.Value != null)
{
if (token.Type == TokenType.EscapedSingleValue && !options.DisableContentSafety)
{
builder.Append(HtmlEncodeString(c.ToString()));
}
else
{
builder.Append(c);
}
}
}
};
}
private static Action <StringBuilder, ContextObject> HandleElementOpen(TokenPair token, Queue <TokenPair> remainder, ParsingOptions options, InferredTemplateModel scope)
{
if (scope != null)
{
scope = scope.GetInferredModelForPath(token.Value, InferredTemplateModel.UsedAs.ConditionalValue);
}
var innerTemplate = Parse(remainder, options, scope);
return((builder, context) =>
{
var c = context.GetContextForPath(token.Value);
//"falsey" values by Javascript standards...
if (c.Exists())
{
innerTemplate(builder, c);
}
});
}
private static Action <StringBuilder, ContextObject> HandleCollectionOpen(TokenPair token, Queue <TokenPair> remainder, ParsingOptions options, InferredTemplateModel scope)
{
if (scope != null)
{
scope = scope.GetInferredModelForPath(token.Value, InferredTemplateModel.UsedAs.Collection);
}
var innerTemplate = Parse(remainder, options, scope);
return((builder, context) =>
{
//if we're in the same scope, just negating, then we want to use the same object
var c = context.GetContextForPath(token.Value);
//"falsey" values by Javascript standards...
if (!c.Exists())
{
return;
}
if (c.Value is IEnumerable && !(c.Value is String) && !(c.Value is IDictionary <string, object>))
{
var index = 0;
foreach (object i in c.Value as IEnumerable)
{
var innerContext = new ContextObject()
{
Value = i,
Key = String.Format("[{0}]", index),
Parent = c
};
innerTemplate(builder, innerContext);
index++;
}
}
else
{
throw new IndexedParseException("'{0}' is used like an array by the template, but is a scalar value or object in your model.", token.Value);
}
});
}
private static Action <StringBuilder, ContextObject> HandleSingleValue(TokenPair token, ParsingOptions options, InferredTemplateModel scope)
{
if (scope != null)
{
scope = scope.GetInferredModelForPath(token.Value, InferredTemplateModel.UsedAs.Scalar);
}
return((builder, context) =>
{
if (context != null)
{
//try to locate the value in the context, if it exists, append it.
var c = context.GetContextForPath(token.Value);
if (c.Value != null)
{
if (token.Type == TokenType.EscapedSingleValue && !options.DisableContentSafety)
{
builder.Append(HtmlEncodeString(c.ToString()));
}
else
{
builder.Append(c);
}
}
}
});
}
private static Action <StringBuilder, ContextObject> Parse(Queue <TokenPair> tokens, ParsingOptions options, InferredTemplateModel currentScope = null)
{
var buildArray = new List <Action <StringBuilder, ContextObject> >();
while (tokens.Any())
{
var currentToken = tokens.Dequeue();
switch (currentToken.Type)
{
case TokenType.Comment:
break;
case TokenType.Content:
buildArray.Add(HandleContent(currentToken.Value));
break;
case TokenType.CollectionOpen:
buildArray.Add(HandleCollectionOpen(currentToken, tokens, options, currentScope));
break;
case TokenType.ElementOpen:
buildArray.Add(HandleElementOpen(currentToken, tokens, options, currentScope));
break;
case TokenType.InvertedElementOpen:
buildArray.Add(HandleInvertedElementOpen(currentToken, tokens, options, currentScope));
break;
case TokenType.CollectionClose:
case TokenType.ElementClose:
// This should immediately return if we're in the element scope,
// and if we're not, this should have been detected by the tokenizer!
return((builder, context) =>
{
foreach (var a in buildArray)
{
a(builder, context);
}
});
case TokenType.EscapedSingleValue:
case TokenType.UnescapedSingleValue:
buildArray.Add(HandleSingleValue(currentToken, options, currentScope));
break;
}
}
return((builder, context) =>
{
foreach (var a in buildArray)
{
a(builder, context);
}
});
}
private static Action <StringBuilder, ContextObject> HandleCollectionOpen(TokenPair token, Queue <TokenPair> remainder, ParsingOptions options, InferredTemplateModel scope)
{
if (scope != null)
{
scope = scope.GetInferredModelForPath(token.Value, InferredTemplateModel.UsedAs.Collection);
}
var innerTemplate = Parse(remainder, options, scope);
return((builder, context) =>
{
//if we're in the same scope, just negating, then we want to use the same object
var c = context.GetContextForPath(token.Value);
//"falsey" values by Javascript standards...
if (!c.Exists())
{
return;
}
IEnumerable cVal = null;
if (c.Value is IEnumerable && !(c.Value is String) && !(c.Value is IDictionary <string, object>))
{
cVal = c.Value as IEnumerable;
}
else
{
//Ok, this is a scalar value or an Object. So lets box it into an IEnumerable
cVal = new ArrayList()
{
c.Value
};
}
var index = 0;
foreach (object i in cVal)
{
var innerContext = new ContextObject()
{
Value = i,
Key = String.Format("[{0}]", index),
Parent = c
};
innerTemplate(builder, innerContext);
index++;
}
});
}
