public void AddSpanAddsSpanToCurrentBlockBuilder()
{
// Arrange
var factory = SpanFactory.CreateCsHtml();
var mockListener = new Mock<ParserVisitor>();
var context = SetupTestContext("phoo");
var builder = new SpanBuilder()
{
Kind = SpanKind.Code
};
builder.Accept(new CSharpSymbol(1, 0, 1, "foo", CSharpSymbolType.Identifier));
var added = builder.Build();
using (context.StartBlock(BlockType.Functions))
{
context.AddSpan(added);
}
var expected = new BlockBuilder()
{
Type = BlockType.Functions,
};
expected.Children.Add(added);
// Assert
ParserTestBase.EvaluateResults(context.CompleteParse(), expected.Build());
}
public void AddSpanAddsSpanToCurrentBlockBuilder()
{
// Arrange
var factory = SpanFactory.CreateCsHtml();
Mock <ParserVisitor> mockListener = new Mock <ParserVisitor>();
var context = SetupTestContext("phoo");
var builder = new SpanBuilder()
{
Kind = SpanKind.Code
};
builder.Accept(new CSharpSymbol(1, 0, 1, "foo", CSharpSymbolType.Identifier));
var added = builder.Build();
using (context.StartBlock(BlockType.Functions))
{
context.AddSpan(added);
}
var expected = new BlockBuilder()
{
Type = BlockType.Functions,
};
expected.Children.Add(added);
// Assert
ParserTestBase.EvaluateResults(context.CompleteParse(), expected.Build());
}
//public override void VisitBlock(Block block)
//{
// BlockBuilder parent = null;
// if (_blocks.Count > 0)
// {
// parent = _blocks.Peek();
// }
// BlockBuilder newBlock = new BlockBuilder(block);
// newBlock.Children.Clear();
// _blocks.Push(newBlock);
// if (block.Type == BlockType.Expression && parent != null)
// {
// VisitExpressionBlock(block, parent);
// }
// else
// {
// base.VisitBlock(block);
// }
// if (_blocks.Count > 1)
// {
// parent.Children.Add(_blocks.Pop().Build());
// }
//}
//public override void VisitSpan(Span span)
//{
// Debug.Assert(_blocks.Count > 0);
// _blocks.Peek().Children.Add(span);
//}
protected override SyntaxTreeNode RewriteBlock(BlockBuilder parent, Block block)
{
BlockBuilder newBlock = new BlockBuilder(block);
newBlock.Children.Clear();
Span ws = block.Children.FirstOrDefault() as Span;
IEnumerable <SyntaxTreeNode> newNodes = block.Children;
if (ws.Content.All(Char.IsWhiteSpace))
{
// Add this node to the parent
SpanBuilder builder = new SpanBuilder(ws);
builder.ClearSymbols();
FillSpan(builder, ws.Start, ws.Content);
parent.Children.Add(builder.Build());
// Remove the old whitespace node
newNodes = block.Children.Skip(1);
}
foreach (SyntaxTreeNode node in newNodes)
{
newBlock.Children.Add(node);
}
return(newBlock.Build());
}
public void AddLiteralChunk(string literal, SyntaxTreeNode association)
{
// If the previous chunk was also a LiteralChunk, append the content of the current node to the previous one.
var literalChunk = _lastChunk as LiteralChunk;
if (literalChunk != null)
{
// Literal chunks are always associated with Spans
var lastSpan = (Span)literalChunk.Association;
var currentSpan = (Span)association;
var builder = new SpanBuilder(lastSpan);
foreach (var symbol in currentSpan.Symbols)
{
builder.Accept(symbol);
}
literalChunk.Association = builder.Build();
literalChunk.Text += literal;
}
else
{
AddChunk(new LiteralChunk
{
Text = literal,
}, association);
}
}
public static Span BuildSpan(string content, SpanKind kind)
{
SpanBuilder builder = new SpanBuilder();
builder.Kind = kind;
builder.Accept(new HtmlSymbol(new SourceLocation(), content, HtmlSymbolType.Text));
return(builder.Build());
}
protected override SyntaxTreeNode RewriteSpan(BlockBuilder parent, Span span)
{
var b = new SpanBuilder(span);
var old = (LiteralAttributeCodeGenerator)span.CodeGenerator;
b.CodeGenerator = old.ValueGenerator != null
? new PreprocessedLiteralAttributeCodeGenerator(old.Prefix, old.ValueGenerator)
: new PreprocessedLiteralAttributeCodeGenerator(old.Prefix, old.Value);
return(b.Build());
}
// 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 KeyValuePair <string, SyntaxTreeNode> ParseSpan(Span span)
{
var afterEquals = false;
var builder = new SpanBuilder
{
CodeGenerator = span.CodeGenerator,
EditHandler = span.EditHandler,
Kind = span.Kind
};
var htmlSymbols = span.Symbols.OfType <HtmlSymbol>().ToArray();
var symbolOffset = 1;
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 (name == null && symbol.Type == HtmlSymbolType.Text)
{
name = symbol.Content;
}
else if (afterEquals)
{
builder.Accept(symbol);
}
else if (symbol.Type == HtmlSymbolType.Equals)
{
// We've found an '=' symbol, this means that the coming symbols will either be a quote
// or value (in the case that the value is unquoted).
// Spaces after/before the equal symbol are not yet supported:
// https://github.com/aspnet/Razor/issues/123
// TODO: Handle malformed tags, if there's an '=' then there MUST be a value.
// https://github.com/aspnet/Razor/issues/104
// Check for attribute start values, aka single or double quote
if (IsQuote(htmlSymbols[i + 1]))
{
// Move past the attribute start so we can accept the true value.
i++;
}
else
{
// Set the symbol offset to 0 so we don't attempt to skip an end quote that doesn't exist.
symbolOffset = 0;
}
afterEquals = true;
}
}
return(new KeyValuePair <string, SyntaxTreeNode>(name, builder.Build()));
}
protected override SyntaxTreeNode RewriteBlock(BlockBuilder parent, Block block)
{
// Collect the content of this node
string content = String.Concat(block.Children.Cast <Span>().Select(s => s.Content));
// Create a new span containing this content
SpanBuilder span = new SpanBuilder();
FillSpan(span, block.Children.Cast <Span>().First().Start, content);
return(span.Build());
}
protected override SyntaxTreeNode RewriteBlock(BlockBuilder parent, Block block)
{
// Collect the content of this node
var content = string.Concat(block.Children.Cast<Span>().Select(s => s.Content));
// Create a new span containing this content
var span = new SpanBuilder();
span.EditHandler = new SpanEditHandler(HtmlTokenizer.Tokenize);
FillSpan(span, block.Children.Cast<Span>().First().Start, content);
return span.Build();
}
protected override SyntaxTreeNode RewriteBlock(BlockBuilder parent, Block block)
{
// Collect the content of this node
var content = string.Concat(block.Children.Cast <Span>().Select(s => s.Content));
// Create a new span containing this content
var span = new SpanBuilder();
span.EditHandler = new SpanEditHandler(HtmlTokenizer.Tokenize);
FillSpan(span, block.Children.Cast <Span>().First().Start, content);
return(span.Build());
}
public void IsCSharpOpenCurlyBrace_SpanWithHtmlSymbol_ReturnFalse()
{
// Arrange
var childBuilder = new SpanBuilder(SourceLocation.Zero);
childBuilder.Accept(SyntaxFactory.Token(SyntaxKind.Text, "hello"));
var child = childBuilder.Build();
// Act
var result = DefaultRazorIndentationFactsService.IsCSharpOpenCurlyBrace(child);
// Assert
Assert.False(result);
}
public void IsCSharpOpenCurlyBrace_SpanWithLeftBrace_ReturnTrue()
{
// Arrange
var childBuilder = new SpanBuilder(SourceLocation.Zero);
childBuilder.Accept(SyntaxFactory.Token(SyntaxKind.LeftBrace, "{"));
var child = childBuilder.Build();
// Act
var result = DefaultRazorIndentationFactsService.IsCSharpOpenCurlyBrace(child);
// Assert
Assert.True(result);
}
private static Span GetSpan(SourceLocation start, string content)
{
var spanBuilder = new SpanBuilder(start);
var tokens = CSharpLanguageCharacteristics.Instance.TokenizeString(content).ToArray();
foreach (var token in tokens)
{
spanBuilder.Accept(token);
}
var span = spanBuilder.Build();
return(span);
}
private static Span CreateMarkupAttribute(SpanBuilder builder, bool isBoundNonStringAttribute)
{
Debug.Assert(builder != null);
// If the attribute was requested by a tag helper but the corresponding property was not a string,
// then treat its value as code. A non-string value can be any C# value so we need to ensure the
// SyntaxTreeNode reflects that.
if (isBoundNonStringAttribute)
{
builder.Kind = SpanKind.Code;
}
return(builder.Build());
}
public void IsCSharpOpenCurlyBrace_SpanWithUnsupportedSymbolType_ReturnFalse(string content, object symbolTypeObject)
{
// Arrange
var symbolType = (SyntaxKind)symbolTypeObject;
var childBuilder = new SpanBuilder(SourceLocation.Zero);
childBuilder.Accept(SyntaxFactory.Token(symbolType, content));
var child = childBuilder.Build();
// Act
var result = DefaultRazorIndentationFactsService.IsCSharpOpenCurlyBrace(child);
// Assert
Assert.False(result);
}
public void IsCSharpOpenCurlyBrace_SpanWithLeftBrace_ReturnTrue()
{
// Arrange
var childBuilder = new SpanBuilder(SourceLocation.Zero);
childBuilder.Accept(new CSharpSymbol("{", CSharpSymbolType.LeftBrace));
var child = childBuilder.Build();
// Act
var result = DefaultRazorIndentationFactsService.IsCSharpOpenCurlyBrace(child);
// Assert
Assert.True(result);
}
protected override SyntaxTreeNode RewriteSpan(BlockBuilder parent, Span span)
{
// Only rewrite if we have a previous that is also markup (CanRewrite does this check for us!)
var previous = parent.Children.LastOrDefault() as Span;
if (previous == null || !CanRewrite(previous))
{
return span;
}
// Merge spans
parent.Children.Remove(previous);
var merged = new SpanBuilder();
FillSpan(merged, previous.Start, previous.Content + span.Content);
return merged.Build();
}
public void IsCSharpOpenCurlyBrace_MultipleSymbols_ReturnFalse()
{
// Arrange
var childBuilder = new SpanBuilder(SourceLocation.Zero);
childBuilder.Accept(new CSharpToken("hello", CSharpTokenType.Identifier));
childBuilder.Accept(new CSharpToken(",", CSharpTokenType.Comma));
var child = childBuilder.Build();
// Act
var result = DefaultRazorIndentationFactsService.IsCSharpOpenCurlyBrace(child);
// Assert
Assert.False(result);
}
protected override SyntaxTreeNode RewriteSpan(BlockBuilder parent, Span span)
{
// Only rewrite if we have a previous that is also markup (CanRewrite does this check for us!)
Span previous = parent.Children.LastOrDefault() as Span;
if (previous == null || !CanRewrite(previous))
{
return(span);
}
// Merge spans
parent.Children.Remove(previous);
SpanBuilder merged = new SpanBuilder();
FillSpan(merged, previous.Start, previous.Content + span.Content);
return(merged.Build());
}
private static Span CreateCodeSpan(string code)
{
// TODO: Correctly reconstruct the syntax tree with correct symbols
var builder = new SpanBuilder();
builder.Kind = SpanKind.Code;
builder.Accept(
new HtmlSymbol(
new SourceLocation(0, 0, 0),
code,
HtmlSymbolType.Text
)
);
return(builder.Build());
}
private static KeyValuePair <string, SyntaxTreeNode> CreateMarkupAttribute(
string name,
SpanBuilder builder,
IReadOnlyDictionary <string, string> attributeValueTypes)
{
string attributeTypeName;
// If the attribute was requested by the tag helper and doesn't happen to be a string then we need to treat
// its value as code. Any non-string value can be any C# value so we need to ensure the SyntaxTreeNode
// reflects that.
if (attributeValueTypes.TryGetValue(name, out attributeTypeName) &&
!IsStringAttribute(attributeTypeName))
{
builder.Kind = SpanKind.Code;
}
return(new KeyValuePair <string, SyntaxTreeNode>(name, builder.Build()));
}
private static SyntaxTreeNode CreateMarkupAttribute(SpanBuilder builder, bool isBoundNonStringAttribute)
{
Span value = null;
// Builder will be null in the case of minimized attributes
if (builder != null)
{
// If the attribute was requested by a tag helper but the corresponding property was not a string,
// then treat its value as code. A non-string value can be any C# value so we need to ensure the
// SyntaxTreeNode reflects that.
if (isBoundNonStringAttribute)
{
builder.Kind = SpanKind.Code;
}
value = builder.Build();
}
return(value);
}
protected override SyntaxTreeNode RewriteBlock(BlockBuilder parent, Block block)
{
// Collect the content of this node
var builder = new StringBuilder();
for (var i = 0; i < block.Children.Count; i++)
{
var childSpan = (Span)block.Children[i];
builder.Append(childSpan.Content);
}
// Create a new span containing this content
var span = new SpanBuilder();
span.EditHandler = new SpanEditHandler(HtmlTokenizer.Tokenize);
Debug.Assert(block.Children.Count > 0);
var start = ((Span)block.Children[0]).Start;
FillSpan(span, start, builder.ToString());
return(span.Build());
}
public Span Span(SpanKind kind, params ISymbol[] symbols)
{
var builder = new SpanBuilder();
builder.Kind = kind;
foreach (var symbol in symbols)
{
builder.Accept(symbol);
}
var span = builder.Build();
if (_last != null)
{
span.Previous = _last;
_last.Next = span;
}
_last = span;
return(span);
}
protected override SyntaxTreeNode RewriteBlock(BlockBuilder parent, Block block)
{
var newBlock = new BlockBuilder(block);
newBlock.Children.Clear();
var ws = block.Children.FirstOrDefault() as Span;
IEnumerable<SyntaxTreeNode> newNodes = block.Children;
if (ws.Content.All(Char.IsWhiteSpace))
{
// Add this node to the parent
var builder = new SpanBuilder(ws);
builder.ClearSymbols();
FillSpan(builder, ws.Start, ws.Content);
parent.Children.Add(builder.Build());
// Remove the old whitespace node
newNodes = block.Children.Skip(1);
}
foreach (SyntaxTreeNode node in newNodes)
{
newBlock.Children.Add(node);
}
return newBlock.Build();
}
private static TryParseResult TryParseBlock(
string tagName,
Block block,
IEnumerable<TagHelperDescriptor> descriptors,
ErrorSink errorSink)
{
// TODO: Accept more than just spans: https://github.com/aspnet/Razor/issues/96.
// The first child will only ever NOT be a Span if a user is doing something like:
// <input @checked />
var childSpan = block.Children.First() as Span;
if (childSpan == null || childSpan.Kind != SpanKind.Markup)
{
errorSink.OnError(
block.Start,
RazorResources.FormatTagHelpers_CannotHaveCSharpInTagDeclaration(tagName),
block.Length);
return null;
}
var builder = new BlockBuilder(block);
// If there's only 1 child it means that it's plain text inside of the attribute.
// i.e. <div class="plain text in attribute">
if (builder.Children.Count == 1)
{
return TryParseSpan(childSpan, descriptors, errorSink);
}
var nameSymbols = childSpan
.Symbols
.OfType<HtmlSymbol>()
.SkipWhile(symbol => !HtmlMarkupParser.IsValidAttributeNameSymbol(symbol)) // Skip prefix
.TakeWhile(nameSymbol => HtmlMarkupParser.IsValidAttributeNameSymbol(nameSymbol))
.Select(nameSymbol => nameSymbol.Content);
var name = string.Concat(nameSymbols);
if (string.IsNullOrEmpty(name))
{
errorSink.OnError(
childSpan.Start,
RazorResources.FormatTagHelpers_AttributesMustHaveAName(tagName),
childSpan.Length);
return null;
}
// Have a name now. Able to determine correct isBoundNonStringAttribute value.
var result = CreateTryParseResult(name, descriptors);
var firstChild = builder.Children[0] as Span;
if (firstChild != null && firstChild.Symbols[0] is HtmlSymbol)
{
var htmlSymbol = firstChild.Symbols[firstChild.Symbols.Count - 1] as HtmlSymbol;
switch (htmlSymbol.Type)
{
// Treat NoQuotes and DoubleQuotes equivalently. We purposefully do not persist NoQuotes
// ValueStyles at code generation time to protect users from rendering dynamic content with spaces
// that can break attributes.
// Ex: <tag my-attribute=@value /> where @value results in the test "hello world".
// This way, the above code would render <tag my-attribute="hello world" />.
case HtmlSymbolType.Equals:
case HtmlSymbolType.DoubleQuote:
result.AttributeValueStyle = HtmlAttributeValueStyle.DoubleQuotes;
break;
case HtmlSymbolType.SingleQuote:
result.AttributeValueStyle = HtmlAttributeValueStyle.SingleQuotes;
break;
default:
result.AttributeValueStyle = HtmlAttributeValueStyle.Minimized;
break;
}
}
// Remove first child i.e. foo="
builder.Children.RemoveAt(0);
// Grabbing last child to check if the attribute value is quoted.
var endNode = block.Children.Last();
if (!endNode.IsBlock)
{
var endSpan = (Span)endNode;
// In some malformed cases e.g. <p bar="false', the last Span (false' in the ex.) may contain more
// than a single HTML symbol. Do not ignore those other symbols.
var symbolCount = endSpan.Symbols.Count();
var endSymbol = symbolCount == 1 ? (HtmlSymbol)endSpan.Symbols.First() : null;
// Checking to see if it's a quoted attribute, if so we should remove end quote
if (endSymbol != null && IsQuote(endSymbol))
{
builder.Children.RemoveAt(builder.Children.Count - 1);
}
}
// We need to rebuild the chunk generators of the builder and its children (this is needed to
// ensure we don't do special attribute chunk generation since this is a tag helper).
block = RebuildChunkGenerators(builder.Build(), result.IsBoundAttribute);
// If there's only 1 child at this point its value could be a simple markup span (treated differently than
// block level elements for attributes).
if (block.Children.Count() == 1)
{
var child = block.Children.First() as Span;
if (child != null)
{
// After pulling apart the block we just have a value span.
var spanBuilder = new SpanBuilder(child);
result.AttributeValueNode =
CreateMarkupAttribute(spanBuilder, result.IsBoundNonStringAttribute);
return result;
}
}
var isFirstSpan = true;
result.AttributeValueNode = ConvertToMarkupAttributeBlock(
block,
(parentBlock, span) =>
{
// If the attribute was requested by a tag helper but the corresponding property was not a
// string, then treat its value as code. A non-string value can be any C# value so we need
// to ensure the SyntaxTreeNode reflects that.
if (result.IsBoundNonStringAttribute)
{
// For bound non-string attributes, we'll only allow a transition span to appear at the very
// beginning of the attribute expression. All later transitions would appear as code so that
// they are part of the generated output. E.g.
// key="@value" -> MyTagHelper.key = value
// key=" @value" -> MyTagHelper.key = @value
// key="1 + @case" -> MyTagHelper.key = 1 + @case
// key="@int + @case" -> MyTagHelper.key = int + @case
// key="@(a + b) -> MyTagHelper.key = a + b
// key="4 + @(a + b)" -> MyTagHelper.key = 4 + @(a + b)
if (isFirstSpan && span.Kind == SpanKind.Transition)
{
// do nothing.
}
else
{
var spanBuilder = new SpanBuilder(span);
if (parentBlock.Type == BlockType.Expression &&
(spanBuilder.Kind == SpanKind.Transition ||
spanBuilder.Kind == SpanKind.MetaCode))
{
// Change to a MarkupChunkGenerator so that the '@' \ parenthesis is generated as part of the output.
spanBuilder.ChunkGenerator = new MarkupChunkGenerator();
}
spanBuilder.Kind = SpanKind.Code;
span = spanBuilder.Build();
}
}
isFirstSpan = false;
return span;
});
return result;
}
private static Block RebuildCodeGenerators(Block block)
{
var builder = new BlockBuilder(block);
var isDynamic = builder.CodeGenerator is DynamicAttributeBlockCodeGenerator;
// We don't want any attribute specific logic here, null out the block code generator.
if (isDynamic || builder.CodeGenerator is AttributeBlockCodeGenerator)
{
builder.CodeGenerator = BlockCodeGenerator.Null;
}
for (var i = 0; i < builder.Children.Count; i++)
{
var child = builder.Children[i];
if (child.IsBlock)
{
// The child is a block, recurse down into the block to rebuild its children
builder.Children[i] = RebuildCodeGenerators((Block)child);
}
else
{
var childSpan = (Span)child;
ISpanCodeGenerator newCodeGenerator = null;
var literalGenerator = childSpan.CodeGenerator as LiteralAttributeCodeGenerator;
if (literalGenerator != null)
{
if (literalGenerator.ValueGenerator == null || literalGenerator.ValueGenerator.Value == null)
{
newCodeGenerator = new MarkupCodeGenerator();
}
else
{
newCodeGenerator = literalGenerator.ValueGenerator.Value;
}
}
else if (isDynamic && childSpan.CodeGenerator == SpanCodeGenerator.Null)
{
// Usually the dynamic code generator handles rendering the null code generators underneath
// it. This doesn't make sense in terms of tag helpers though, we need to change null code
// generators to markup code generators.
newCodeGenerator = new MarkupCodeGenerator();
}
// If we have a new code generator we'll need to re-build the child
if (newCodeGenerator != null)
{
var childSpanBuilder = new SpanBuilder(childSpan)
{
CodeGenerator = newCodeGenerator
};
builder.Children[i] = childSpanBuilder.Build();
}
}
}
return(builder.Build());
}
private static Block RebuildChunkGenerators(Block block, bool isBound)
{
var builder = new BlockBuilder(block);
// Don't want to rebuild unbound dynamic attributes. They need to run through the conditional attribute
// removal system at runtime. A conditional attribute at the parse tree rewriting level is defined by
// having at least 1 child with a DynamicAttributeBlockChunkGenerator.
if (!isBound &&
block.Children.Any(
child => child.IsBlock &&
((Block)child).ChunkGenerator is DynamicAttributeBlockChunkGenerator))
{
// The parent chunk generator must be removed because it's normally responsible for conditionally
// generating the attribute prefix (class=") and suffix ("). The prefix and suffix concepts aren't
// applicable for the TagHelper use case since the attributes are put into a dictionary like object as
// name value pairs.
builder.ChunkGenerator = ParentChunkGenerator.Null;
return(builder.Build());
}
var isDynamic = builder.ChunkGenerator is DynamicAttributeBlockChunkGenerator;
// We don't want any attribute specific logic here, null out the block chunk generator.
if (isDynamic || builder.ChunkGenerator is AttributeBlockChunkGenerator)
{
builder.ChunkGenerator = ParentChunkGenerator.Null;
}
for (var i = 0; i < builder.Children.Count; i++)
{
var child = builder.Children[i];
if (child.IsBlock)
{
// The child is a block, recurse down into the block to rebuild its children
builder.Children[i] = RebuildChunkGenerators((Block)child, isBound);
}
else
{
var childSpan = (Span)child;
ISpanChunkGenerator newChunkGenerator = null;
var literalGenerator = childSpan.ChunkGenerator as LiteralAttributeChunkGenerator;
if (literalGenerator != null)
{
if (literalGenerator.ValueGenerator == null || literalGenerator.ValueGenerator.Value == null)
{
newChunkGenerator = new MarkupChunkGenerator();
}
else
{
newChunkGenerator = literalGenerator.ValueGenerator.Value;
}
}
else if (isDynamic && childSpan.ChunkGenerator == SpanChunkGenerator.Null)
{
// Usually the dynamic chunk generator handles creating the null chunk generators underneath
// it. This doesn't make sense in terms of tag helpers though, we need to change null code
// generators to markup chunk generators.
newChunkGenerator = new MarkupChunkGenerator();
}
// If we have a new chunk generator we'll need to re-build the child
if (newChunkGenerator != null)
{
var childSpanBuilder = new SpanBuilder(childSpan)
{
ChunkGenerator = newChunkGenerator
};
builder.Children[i] = childSpanBuilder.Build();
}
}
}
return(builder.Build());
}
private static TryParseResult TryParseBlock(
string tagName,
Block block,
IEnumerable <TagHelperDescriptor> descriptors,
ErrorSink errorSink)
{
// TODO: Accept more than just spans: https://github.com/aspnet/Razor/issues/96.
// The first child will only ever NOT be a Span if a user is doing something like:
// <input @checked />
var childSpan = block.Children.First() as Span;
if (childSpan == null || childSpan.Kind != SpanKind.Markup)
{
errorSink.OnError(
block.Start,
RazorResources.FormatTagHelpers_CannotHaveCSharpInTagDeclaration(tagName),
block.Length);
return(null);
}
var builder = new BlockBuilder(block);
// If there's only 1 child it means that it's plain text inside of the attribute.
// i.e. <div class="plain text in attribute">
if (builder.Children.Count == 1)
{
return(TryParseSpan(childSpan, descriptors, errorSink));
}
var nameSymbols = childSpan
.Symbols
.OfType <HtmlSymbol>()
.SkipWhile(symbol => !HtmlMarkupParser.IsValidAttributeNameSymbol(symbol)) // Skip prefix
.TakeWhile(nameSymbol => HtmlMarkupParser.IsValidAttributeNameSymbol(nameSymbol))
.Select(nameSymbol => nameSymbol.Content);
var name = string.Concat(nameSymbols);
if (string.IsNullOrEmpty(name))
{
errorSink.OnError(
childSpan.Start,
RazorResources.FormatTagHelpers_AttributesMustHaveAName(tagName),
childSpan.Length);
return(null);
}
// Have a name now. Able to determine correct isBoundNonStringAttribute value.
var result = CreateTryParseResult(name, descriptors);
var firstChild = builder.Children[0] as Span;
if (firstChild != null && firstChild.Symbols[0] is HtmlSymbol)
{
var htmlSymbol = firstChild.Symbols[firstChild.Symbols.Count - 1] as HtmlSymbol;
switch (htmlSymbol.Type)
{
// Treat NoQuotes and DoubleQuotes equivalently. We purposefully do not persist NoQuotes
// ValueStyles at code generation time to protect users from rendering dynamic content with spaces
// that can break attributes.
// Ex: <tag my-attribute=@value /> where @value results in the test "hello world".
// This way, the above code would render <tag my-attribute="hello world" />.
case HtmlSymbolType.Equals:
case HtmlSymbolType.DoubleQuote:
result.AttributeValueStyle = HtmlAttributeValueStyle.DoubleQuotes;
break;
case HtmlSymbolType.SingleQuote:
result.AttributeValueStyle = HtmlAttributeValueStyle.SingleQuotes;
break;
default:
result.AttributeValueStyle = HtmlAttributeValueStyle.Minimized;
break;
}
}
// Remove first child i.e. foo="
builder.Children.RemoveAt(0);
// Grabbing last child to check if the attribute value is quoted.
var endNode = block.Children.Last();
if (!endNode.IsBlock)
{
var endSpan = (Span)endNode;
// In some malformed cases e.g. <p bar="false', the last Span (false' in the ex.) may contain more
// than a single HTML symbol. Do not ignore those other symbols.
var symbolCount = endSpan.Symbols.Count();
var endSymbol = symbolCount == 1 ? (HtmlSymbol)endSpan.Symbols.First() : null;
// Checking to see if it's a quoted attribute, if so we should remove end quote
if (endSymbol != null && IsQuote(endSymbol))
{
builder.Children.RemoveAt(builder.Children.Count - 1);
}
}
// We need to rebuild the chunk generators of the builder and its children (this is needed to
// ensure we don't do special attribute chunk generation since this is a tag helper).
block = RebuildChunkGenerators(builder.Build(), result.IsBoundAttribute);
// If there's only 1 child at this point its value could be a simple markup span (treated differently than
// block level elements for attributes).
if (block.Children.Count() == 1)
{
var child = block.Children.First() as Span;
if (child != null)
{
// After pulling apart the block we just have a value span.
var spanBuilder = new SpanBuilder(child);
result.AttributeValueNode =
CreateMarkupAttribute(spanBuilder, result.IsBoundNonStringAttribute);
return(result);
}
}
var isFirstSpan = true;
result.AttributeValueNode = ConvertToMarkupAttributeBlock(
block,
(parentBlock, span) =>
{
// If the attribute was requested by a tag helper but the corresponding property was not a
// string, then treat its value as code. A non-string value can be any C# value so we need
// to ensure the SyntaxTreeNode reflects that.
if (result.IsBoundNonStringAttribute)
{
// For bound non-string attributes, we'll only allow a transition span to appear at the very
// beginning of the attribute expression. All later transitions would appear as code so that
// they are part of the generated output. E.g.
// key="@value" -> MyTagHelper.key = value
// key=" @value" -> MyTagHelper.key = @value
// key="1 + @case" -> MyTagHelper.key = 1 + @case
// key="@int + @case" -> MyTagHelper.key = int + @case
// key="@(a + b) -> MyTagHelper.key = a + b
// key="4 + @(a + b)" -> MyTagHelper.key = 4 + @(a + b)
if (isFirstSpan && span.Kind == SpanKind.Transition)
{
// do nothing.
}
else
{
var spanBuilder = new SpanBuilder(span);
if (parentBlock.Type == BlockType.Expression &&
(spanBuilder.Kind == SpanKind.Transition ||
spanBuilder.Kind == SpanKind.MetaCode))
{
// Change to a MarkupChunkGenerator so that the '@' \ parenthesis is generated as part of the output.
spanBuilder.ChunkGenerator = new MarkupChunkGenerator();
}
spanBuilder.Kind = SpanKind.Code;
span = spanBuilder.Build();
}
}
isFirstSpan = false;
return(span);
});
return(result);
}
private static Span CreateMarkupAttribute(SpanBuilder builder, bool isBoundNonStringAttribute)
{
Debug.Assert(builder != null);
// If the attribute was requested by a tag helper but the corresponding property was not a string,
// then treat its value as code. A non-string value can be any C# value so we need to ensure the
// SyntaxTreeNode reflects that.
if (isBoundNonStringAttribute)
{
builder.Kind = SpanKind.Code;
}
return builder.Build();
}
private static Block RebuildChunkGenerators(Block block, bool isBound)
{
var builder = new BlockBuilder(block);
// Don't want to rebuild unbound dynamic attributes. They need to run through the conditional attribute
// removal system at runtime. A conditional attribute at the parse tree rewriting level is defined by
// having at least 1 child with a DynamicAttributeBlockChunkGenerator.
if (!isBound &&
block.Children.Any(
child => child.IsBlock &&
((Block)child).ChunkGenerator is DynamicAttributeBlockChunkGenerator))
{
// The parent chunk generator must be removed because it's normally responsible for conditionally
// generating the attribute prefix (class=") and suffix ("). The prefix and suffix concepts aren't
// applicable for the TagHelper use case since the attributes are put into a dictionary like object as
// name value pairs.
builder.ChunkGenerator = ParentChunkGenerator.Null;
return builder.Build();
}
var isDynamic = builder.ChunkGenerator is DynamicAttributeBlockChunkGenerator;
// We don't want any attribute specific logic here, null out the block chunk generator.
if (isDynamic || builder.ChunkGenerator is AttributeBlockChunkGenerator)
{
builder.ChunkGenerator = ParentChunkGenerator.Null;
}
for (var i = 0; i < builder.Children.Count; i++)
{
var child = builder.Children[i];
if (child.IsBlock)
{
// The child is a block, recurse down into the block to rebuild its children
builder.Children[i] = RebuildChunkGenerators((Block)child, isBound);
}
else
{
var childSpan = (Span)child;
ISpanChunkGenerator newChunkGenerator = null;
var literalGenerator = childSpan.ChunkGenerator as LiteralAttributeChunkGenerator;
if (literalGenerator != null)
{
if (literalGenerator.ValueGenerator == null || literalGenerator.ValueGenerator.Value == null)
{
newChunkGenerator = new MarkupChunkGenerator();
}
else
{
newChunkGenerator = literalGenerator.ValueGenerator.Value;
}
}
else if (isDynamic && childSpan.ChunkGenerator == SpanChunkGenerator.Null)
{
// Usually the dynamic chunk generator handles creating the null chunk generators underneath
// it. This doesn't make sense in terms of tag helpers though, we need to change null code
// generators to markup chunk generators.
newChunkGenerator = new MarkupChunkGenerator();
}
// If we have a new chunk generator we'll need to re-build the child
if (newChunkGenerator != null)
{
var childSpanBuilder = new SpanBuilder(childSpan)
{
ChunkGenerator = newChunkGenerator
};
builder.Children[i] = childSpanBuilder.Build();
}
}
}
return builder.Build();
}