// This method handles cases when the attribute is a simple span attribute such as
// class="something moresomething". This does not handle complex attributes such as
// class="@myclass". Therefore the span.Content is equivalent to the entire attribute.
private static TryParseResult TryParseSpan(
Span span,
IEnumerable <TagHelperDescriptor> descriptors,
ErrorSink errorSink,
HashSet <string> processedBoundAttributeNames)
{
var afterEquals = false;
var builder = new SpanBuilder(span.Start)
{
ChunkGenerator = span.ChunkGenerator,
EditHandler = span.EditHandler,
Kind = span.Kind
};
// Will contain symbols that represent a single attribute value: <input| class="btn"| />
var htmlSymbols = span.Symbols.OfType <HtmlSymbol>().ToArray();
var capturedAttributeValueStart = false;
var attributeValueStartLocation = span.Start;
// Default to DoubleQuotes. We purposefully do not persist NoQuotes ValueStyle to stay consistent with the
// TryParseBlock() variation of attribute parsing.
var attributeValueStyle = AttributeStructure.DoubleQuotes;
// The symbolOffset is initialized to 0 to expect worst case: "class=". If a quote is found later on for
// the attribute value the symbolOffset is adjusted accordingly.
var symbolOffset = 0;
string name = null;
// Iterate down through the symbols to find the name and the start of the value.
// We subtract the symbolOffset so we don't accept an ending quote of a span.
for (var i = 0; i < htmlSymbols.Length - symbolOffset; i++)
{
var symbol = htmlSymbols[i];
if (afterEquals)
{
// We've captured all leading whitespace, the attribute name, and an equals with an optional
// quote/double quote. We're now at: " asp-for='|...'" or " asp-for=|..."
// The goal here is to capture all symbols until the end of the attribute. Note this will not
// consume an ending quote due to the symbolOffset.
// When symbols are accepted into SpanBuilders, their locations get altered to be offset by the
// parent which is why we need to mark our start location prior to adding the symbol.
// This is needed to know the location of the attribute value start within the document.
if (!capturedAttributeValueStart)
{
capturedAttributeValueStart = true;
attributeValueStartLocation = symbol.Start;
}
builder.Accept(symbol);
}
else if (name == null && HtmlMarkupParser.IsValidAttributeNameSymbol(symbol))
{
// We've captured all leading whitespace prior to the attribute name.
// We're now at: " |asp-for='...'" or " |asp-for=..."
// The goal here is to capture the attribute name.
var nameBuilder = new StringBuilder();
// Move the indexer past the attribute name symbols.
for (var j = i; j < htmlSymbols.Length; j++)
{
var nameSymbol = htmlSymbols[j];
if (!HtmlMarkupParser.IsValidAttributeNameSymbol(nameSymbol))
{
break;
}
nameBuilder.Append(nameSymbol.Content);
i++;
}
i--;
name = nameBuilder.ToString();
attributeValueStartLocation = SourceLocationTracker.Advance(attributeValueStartLocation, name);
}
else if (symbol.Type == HtmlSymbolType.Equals)
{
// We've captured all leading whitespace and the attribute name.
// We're now at: " asp-for|='...'" or " asp-for|=..."
// The goal here is to consume the equal sign and the optional single/double-quote.
// The coming symbols will either be a quote or value (in the case that the value is unquoted).
SourceLocation symbolStartLocation;
// Skip the whitespace preceding the start of the attribute value.
do
{
i++; // Start from the symbol after '='.
} while (i < htmlSymbols.Length &&
(htmlSymbols[i].Type == HtmlSymbolType.WhiteSpace ||
htmlSymbols[i].Type == HtmlSymbolType.NewLine));
// Check for attribute start values, aka single or double quote
if (i < htmlSymbols.Length && IsQuote(htmlSymbols[i]))
{
if (htmlSymbols[i].Type == HtmlSymbolType.SingleQuote)
{
attributeValueStyle = AttributeStructure.SingleQuotes;
}
symbolStartLocation = htmlSymbols[i].Start;
// If there's a start quote then there must be an end quote to be valid, skip it.
symbolOffset = 1;
}
else
{
// We are at the symbol after equals. Go back to equals to ensure we don't skip past that symbol.
i--;
symbolStartLocation = symbol.Start;
}
attributeValueStartLocation = new SourceLocation(
symbolStartLocation.FilePath,
symbolStartLocation.AbsoluteIndex + 1,
symbolStartLocation.LineIndex,
symbolStartLocation.CharacterIndex + 1);
afterEquals = true;
}
else if (symbol.Type == HtmlSymbolType.WhiteSpace)
{
// We're at the start of the attribute, this branch may be hit on the first iterations of
// the loop since the parser separates attributes with their spaces included as symbols.
// We're at: "| asp-for='...'" or "| asp-for=..."
// Note: This will not be hit even for situations like asp-for ="..." because the core Razor
// parser currently does not know how to handle attributes in that format. This will be addressed
// by https://github.com/aspnet/Razor/issues/123.
attributeValueStartLocation = SourceLocationTracker.Advance(attributeValueStartLocation, symbol.Content);
}
}
// After all symbols have been added we need to set the builders start position so we do not indirectly
// modify the span's start location.
builder.Start = attributeValueStartLocation;
if (name == null)
{
// We couldn't find a name, if the original span content was whitespace it ultimately means the tag
// that owns this "attribute" is malformed and is expecting a user to type a new attribute.
// ex: <myTH class="btn"| |
if (!string.IsNullOrWhiteSpace(span.Content))
{
var location = new SourceSpan(span.Start, span.Content.Length);
var diagnostic = RazorDiagnosticFactory.CreateParsing_TagHelperAttributeListMustBeWellFormed(location);
errorSink.OnError(diagnostic);
}
return(null);
}
var result = CreateTryParseResult(name, descriptors, processedBoundAttributeNames);
// If we're not after an equal then we should treat the value as if it were a minimized attribute.
Span attributeValue = null;
if (afterEquals)
{
attributeValue = CreateMarkupAttribute(builder, result);
}
else
{
attributeValueStyle = AttributeStructure.Minimized;
}
result.AttributeValueNode = attributeValue;
result.AttributeStructure = attributeValueStyle;
return(result);
}
private static SyntaxList <RazorSyntaxNode> GetRewrittenChildren(
string tagName,
bool validStructure,
MarkupTagBlockSyntax tagBlock,
TagHelperBinding bindingResult,
RazorParserFeatureFlags featureFlags,
ErrorSink errorSink,
RazorSourceDocument source)
{
var tagHelperBuilder = SyntaxListBuilder <RazorSyntaxNode> .Create();
var processedBoundAttributeNames = new HashSet <string>(StringComparer.OrdinalIgnoreCase);
if (tagBlock.Children.Count == 1)
{
// Tag with no attributes. We have nothing to rewrite here.
return(tagBlock.Children);
}
// Add the tag start
tagHelperBuilder.Add(tagBlock.Children.First());
// We skip the first child "<tagname" and take everything up to the ending portion of the tag ">" or "/>".
// If the tag does not have a valid structure then there's no close angle to ignore.
var tokenOffset = validStructure ? 1 : 0;
for (var i = 1; i < tagBlock.Children.Count - tokenOffset; i++)
{
var isMinimized = false;
var attributeNameLocation = SourceLocation.Undefined;
var child = tagBlock.Children[i];
TryParseResult result;
if (child is MarkupAttributeBlockSyntax attributeBlock)
{
attributeNameLocation = attributeBlock.Name.GetSourceLocation(source);
result = TryParseAttribute(
tagName,
attributeBlock,
bindingResult.Descriptors,
errorSink,
processedBoundAttributeNames);
tagHelperBuilder.Add(result.RewrittenAttribute);
}
else if (child is MarkupMinimizedAttributeBlockSyntax minimizedAttributeBlock)
{
isMinimized = true;
attributeNameLocation = minimizedAttributeBlock.Name.GetSourceLocation(source);
result = TryParseMinimizedAttribute(
tagName,
minimizedAttributeBlock,
bindingResult.Descriptors,
errorSink,
processedBoundAttributeNames);
tagHelperBuilder.Add(result.RewrittenAttribute);
}
else if (child is CSharpCodeBlockSyntax)
{
// TODO: Accept more than just Markup attributes: https://github.com/aspnet/Razor/issues/96.
// Something like:
// <input @checked />
var location = new SourceSpan(child.GetSourceLocation(source), child.FullWidth);
var diagnostic = RazorDiagnosticFactory.CreateParsing_TagHelpersCannotHaveCSharpInTagDeclaration(location, tagName);
errorSink.OnError(diagnostic);
result = null;
}
else if (child is MarkupTextLiteralSyntax)
{
// If the original span content was whitespace it ultimately means the tag
// that owns this "attribute" is malformed and is expecting a user to type a new attribute.
// ex: <myTH class="btn"| |
var literalContent = child.GetContent();
if (!string.IsNullOrWhiteSpace(literalContent))
{
var location = child.GetSourceSpan(source);
var diagnostic = RazorDiagnosticFactory.CreateParsing_TagHelperAttributeListMustBeWellFormed(location);
errorSink.OnError(diagnostic);
}
result = null;
}
else
{
result = null;
}
// Only want to track the attribute if we succeeded in parsing its corresponding Block/Span.
if (result == null)
{
// Error occurred while parsing the attribute. Don't try parsing the rest to avoid misleading errors.
for (var j = i; j < tagBlock.Children.Count; j++)
{
tagHelperBuilder.Add(tagBlock.Children[j]);
}
return(tagHelperBuilder.ToList());
}
// Check if it's a non-boolean bound attribute that is minimized or if it's a bound
// non-string attribute that has null or whitespace content.
var isValidMinimizedAttribute = featureFlags.AllowMinimizedBooleanTagHelperAttributes && result.IsBoundBooleanAttribute;
if ((isMinimized &&
result.IsBoundAttribute &&
!isValidMinimizedAttribute) ||
(!isMinimized &&
result.IsBoundNonStringAttribute &&
string.IsNullOrWhiteSpace(GetAttributeValueContent(result.RewrittenAttribute))))
{
var errorLocation = new SourceSpan(attributeNameLocation, result.AttributeName.Length);
var propertyTypeName = GetPropertyType(result.AttributeName, bindingResult.Descriptors);
var diagnostic = RazorDiagnosticFactory.CreateTagHelper_EmptyBoundAttribute(errorLocation, result.AttributeName, tagName, propertyTypeName);
errorSink.OnError(diagnostic);
}
// Check if the attribute was a prefix match for a tag helper dictionary property but the
// dictionary key would be the empty string.
if (result.IsMissingDictionaryKey)
{
var errorLocation = new SourceSpan(attributeNameLocation, result.AttributeName.Length);
var diagnostic = RazorDiagnosticFactory.CreateParsing_TagHelperIndexerAttributeNameMustIncludeKey(errorLocation, result.AttributeName, tagName);
errorSink.OnError(diagnostic);
}
}
if (validStructure)
{
// Add the tag end.
tagHelperBuilder.Add(tagBlock.Children[tagBlock.Children.Count - 1]);
}
return(tagHelperBuilder.ToList());
}
public static MarkupTagHelperStartTagSyntax Rewrite(
string tagName,
RazorParserFeatureFlags featureFlags,
MarkupStartTagSyntax startTag,
TagHelperBinding bindingResult,
ErrorSink errorSink,
RazorSourceDocument source)
{
var processedBoundAttributeNames = new HashSet <string>(StringComparer.OrdinalIgnoreCase);
var attributes = startTag.Attributes;
var attributeBuilder = SyntaxListBuilder <RazorSyntaxNode> .Create();
for (var i = 0; i < startTag.Attributes.Count; i++)
{
var isMinimized = false;
var attributeNameLocation = SourceLocation.Undefined;
var child = startTag.Attributes[i];
TryParseResult result;
if (child is MarkupAttributeBlockSyntax attributeBlock)
{
attributeNameLocation = attributeBlock.Name.GetSourceLocation(source);
result = TryParseAttribute(
tagName,
attributeBlock,
bindingResult.Descriptors,
errorSink,
processedBoundAttributeNames);
attributeBuilder.Add(result.RewrittenAttribute);
}
else if (child is MarkupMinimizedAttributeBlockSyntax minimizedAttributeBlock)
{
isMinimized = true;
attributeNameLocation = minimizedAttributeBlock.Name.GetSourceLocation(source);
result = TryParseMinimizedAttribute(
tagName,
minimizedAttributeBlock,
bindingResult.Descriptors,
errorSink,
processedBoundAttributeNames);
attributeBuilder.Add(result.RewrittenAttribute);
}
else if (child is MarkupMiscAttributeContentSyntax miscContent)
{
foreach (var contentChild in miscContent.Children)
{
if (contentChild is CSharpCodeBlockSyntax codeBlock)
{
// TODO: Accept more than just Markup attributes: https://github.com/aspnet/Razor/issues/96.
// Something like:
// <input @checked />
var location = new SourceSpan(codeBlock.GetSourceLocation(source), codeBlock.FullWidth);
var diagnostic = RazorDiagnosticFactory.CreateParsing_TagHelpersCannotHaveCSharpInTagDeclaration(location, tagName);
errorSink.OnError(diagnostic);
break;
}
else
{
// If the original span content was whitespace it ultimately means the tag
// that owns this "attribute" is malformed and is expecting a user to type a new attribute.
// ex: <myTH class="btn"| |
var literalContent = contentChild.GetContent();
if (!string.IsNullOrWhiteSpace(literalContent))
{
var location = contentChild.GetSourceSpan(source);
var diagnostic = RazorDiagnosticFactory.CreateParsing_TagHelperAttributeListMustBeWellFormed(location);
errorSink.OnError(diagnostic);
break;
}
}
}
result = null;
}
else
{
result = null;
}
// Only want to track the attribute if we succeeded in parsing its corresponding Block/Span.
if (result == null)
{
// Error occurred while parsing the attribute. Don't try parsing the rest to avoid misleading errors.
for (var j = i; j < startTag.Attributes.Count; j++)
{
attributeBuilder.Add(startTag.Attributes[j]);
}
break;
}
// Check if it's a non-boolean bound attribute that is minimized or if it's a bound
// non-string attribute that has null or whitespace content.
var isValidMinimizedAttribute = featureFlags.AllowMinimizedBooleanTagHelperAttributes && result.IsBoundBooleanAttribute;
if ((isMinimized &&
result.IsBoundAttribute &&
!isValidMinimizedAttribute) ||
(!isMinimized &&
result.IsBoundNonStringAttribute &&
string.IsNullOrWhiteSpace(GetAttributeValueContent(result.RewrittenAttribute))))
{
var errorLocation = new SourceSpan(attributeNameLocation, result.AttributeName.Length);
var propertyTypeName = GetPropertyType(result.AttributeName, bindingResult.Descriptors);
var diagnostic = RazorDiagnosticFactory.CreateTagHelper_EmptyBoundAttribute(errorLocation, result.AttributeName, tagName, propertyTypeName);
errorSink.OnError(diagnostic);
}
// Check if the attribute was a prefix match for a tag helper dictionary property but the
// dictionary key would be the empty string.
if (result.IsMissingDictionaryKey)
{
var errorLocation = new SourceSpan(attributeNameLocation, result.AttributeName.Length);
var diagnostic = RazorDiagnosticFactory.CreateParsing_TagHelperIndexerAttributeNameMustIncludeKey(errorLocation, result.AttributeName, tagName);
errorSink.OnError(diagnostic);
}
}
if (attributeBuilder.Count > 0)
{
// This means we rewrote something. Use the new set of attributes.
attributes = attributeBuilder.ToList();
}
var tagHelperStartTag = SyntaxFactory.MarkupTagHelperStartTag(
startTag.OpenAngle, startTag.Bang, startTag.Name, attributes, startTag.ForwardSlash, startTag.CloseAngle);
return(tagHelperStartTag.WithSpanContext(startTag.GetSpanContext()));
}
