huahaofeng
/
aspnetcore
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

Updated the Comments detection to comply with HTML 5 specification

This commit is contained in:
Artak Mkrtchyan 2018-03-05 17:28:23 -08:00
parent 6885fb15d0
commit 33814fb634
No known key found for this signature in database
GPG Key ID: 64D580ACBA8CA645
4 changed files with 170 additions and 35 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

151
src/Microsoft.AspNetCore.Razor.Language/Legacy/HtmlMarkupParser.cs
View File

@ -492,7 +492,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
if (AcceptAndMoveNext())
{
if (CurrentSymbol.Type == HtmlSymbolType.DoubleHyphen)
if (IsHtmlCommentAhead())
{
using (Context.Builder.StartBlock(BlockKindInternal.HtmlComment))
{
@ -505,32 +505,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
SkipToAndParseCode(HtmlSymbolType.DoubleHyphen);
if (At(HtmlSymbolType.DoubleHyphen))
{
var lastDoubleHyphen = CurrentSymbol;
AcceptWhile(s =>
{
if (NextIs(HtmlSymbolType.DoubleHyphen))
{
lastDoubleHyphen = s;
return true;
}
NextToken();
EnsureCurrent();
return false;
});
if (At(HtmlSymbolType.Text) &&
string.Equals(CurrentSymbol.Content, "-", StringComparison.Ordinal))
{
// Doing this here to maintain the order of symbols
if (!NextIs(HtmlSymbolType.CloseAngle))
{
Accept(lastDoubleHyphen);
lastDoubleHyphen = null;
}
AcceptAndMoveNext();
}
var lastDoubleHyphen = AcceptAllButLastDoubleHypens();
if (At(HtmlSymbolType.CloseAngle))
{
@ -541,7 +516,6 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
Accept(lastDoubleHyphen);
AcceptAndMoveNext();
Output(SpanKindInternal.Markup, AcceptedCharactersInternal.None);
return true;
}
else if (lastDoubleHyphen != null)
@ -551,8 +525,6 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
}
}
}
return false;
}
else if (CurrentSymbol.Type == HtmlSymbolType.LeftBracket)
{
@ -571,6 +543,125 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
return false;
}
private HtmlSymbol AcceptAllButLastDoubleHypens()
{
var lastDoubleHyphen = CurrentSymbol;
AcceptWhile(s =>
{
if (NextIs(HtmlSymbolType.DoubleHyphen))
{
lastDoubleHyphen = s;
return true;
}
NextToken();
EnsureCurrent();
return false;
});
if (At(HtmlSymbolType.Text) && IsDashSymbol(CurrentSymbol))
{
// Doing this here to maintain the order of symbols
if (!NextIs(HtmlSymbolType.CloseAngle))
{
Accept(lastDoubleHyphen);
lastDoubleHyphen = null;
}
AcceptAndMoveNext();
}
return lastDoubleHyphen;
}
private static bool IsDashSymbol(HtmlSymbol symbol)
{
return string.Equals(symbol.Content, "-", StringComparison.Ordinal);
}
private bool IsHtmlCommentAhead()
{
/*
* From HTML5 Specification, available at http://www.w3.org/TR/html52/syntax.html#comments
*
* Comments must have the following format:
* 1. The string "<!--"
* 2. Optionally, text, with the additional restriction that the text
* 2.1 must not start with the string ">" nor start with the string "->"
* 2.2 nor contain the strings "<!--", "-->", or "--!>"
* 2.3 nor end with the string "<!-".
* 3. The string "-->"
*
* */
if (CurrentSymbol.Type != HtmlSymbolType.DoubleHyphen)
{
return false;
}
// Check condition 2.1
if (NextIs(HtmlSymbolType.CloseAngle) || NextIs(next => IsDashSymbol(next) && NextIs(HtmlSymbolType.CloseAngle)))
{
return false;
}
// Check condition 2.2
bool isValidComment = false;
LookaheadUntil((s, p) =>
{
bool breakLookahead = false;
if (s.Type == HtmlSymbolType.DoubleHyphen)
{
if (NextIs(HtmlSymbolType.CloseAngle))
{
// We're at the end of a comment. check the condition 2.3 to make sure the text ending is allowed.
isValidComment = !EndsWithSymbolsSequence(p, HtmlSymbolType.OpenAngle, HtmlSymbolType.Bang, HtmlSymbolType.DoubleHyphen);
breakLookahead = true;
}
else if (NextIs(ns => IsDashSymbol(ns) && NextIs(HtmlSymbolType.CloseAngle)))
{
// This is also a valid closing comment case, as the dashes lookup is treated with DoubleHyphen symbols first.
isValidComment = true;
breakLookahead = true;
}
else if (NextIs(ns => ns.Type == HtmlSymbolType.Bang && NextIs(HtmlSymbolType.CloseAngle)))
{
isValidComment = false;
breakLookahead = true;
}
}
else if (s.Type == HtmlSymbolType.OpenAngle)
{
if (NextIs(ns => ns.Type == HtmlSymbolType.Bang && NextIs(HtmlSymbolType.DoubleHyphen)))
{
isValidComment = false;
breakLookahead = true;
}
}
return breakLookahead;
});
return isValidComment;
}
private bool EndsWithSymbolsSequence(IEnumerable<HtmlSymbol> symbols, params HtmlSymbolType[] sequenceToMatchWith)
{
int index = sequenceToMatchWith.Length;
foreach (var previousSymbol in symbols)
{
if (index == 0)
{
break;
}
if (sequenceToMatchWith[--index] != previousSymbol.Type)
return false;
}
return index == 0;
}
private bool CData()
{
if (CurrentSymbol.Type == HtmlSymbolType.Text && string.Equals(CurrentSymbol.Content, "cdata", StringComparison.OrdinalIgnoreCase))

47
src/Microsoft.AspNetCore.Razor.Language/Legacy/TokenizerBackedParser.cs
View File

@ -109,6 +109,53 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
return symbols[count];
}
/// <summary>
/// Looks forward until the specified condition is met.
/// </summary>
/// <param name="condition">A predicate accepting the symbol being evaluated and the list of symbols which have been looped through.</param>
/// <returns>true, if the condition was met. false - if the condition wasn't met and the last symbol has already been processed.</returns>
/// <remarks>The list of previous symbols is passed in the reverse order. So the last processed element will be the first one in the list.</remarks>
protected bool LookaheadUntil(Func<TSymbol, IEnumerable<TSymbol>, bool> condition)
{
if (condition == null)
{
throw new ArgumentNullException(nameof(condition));
}
bool matchFound = false;
// We add 1 in order to store the current symbol.
var symbols = new List<TSymbol>();
symbols.Add(CurrentSymbol);
while (true)
{
if (!NextToken())
{
break;
}
symbols.Add(CurrentSymbol);
if (condition(CurrentSymbol, symbols.Reverse<TSymbol>()))
{
matchFound = true;
break;
}
}
// Restore Tokenizer's location to where it was pointing before the look-ahead.
for (var i = symbols.Count - 1; i >= 0; i--)
{
PutBack(symbols[i]);
}
// The PutBacks above will set CurrentSymbol to null. EnsureCurrent will set our CurrentSymbol to the
// next symbol.
EnsureCurrent();
return matchFound;
}
protected internal bool NextToken()
{
PreviousSymbol = CurrentSymbol;

4
test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/HtmlBlockTest.cs
View File

@ -419,9 +419,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
ParseBlockTest(
"<!--<foo>",
new MarkupBlock(
new HtmlCommentBlock(Factory.Markup("<!--").Accepts(AcceptedCharactersInternal.None)),
Factory.Markup("<foo>").Accepts(AcceptedCharactersInternal.WhiteSpace),
Factory.EmptyHtml()));
Factory.Markup("<!--<foo>").Accepts(AcceptedCharactersInternal.None)));
}
[Fact]

3
test/Microsoft.AspNetCore.Razor.Language.Test/Legacy/HtmlDocumentTest.cs
View File

@ -219,8 +219,7 @@ namespace Microsoft.AspNetCore.Razor.Language.Legacy
Factory.Markup("Foo Baz"),
BlockFactory.HtmlCommentBlock("Foo"),
Factory.Markup("Bar"),
new HtmlCommentBlock(Factory.Markup("<!--").Accepts(AcceptedCharactersInternal.None)),
Factory.Markup("F> Qux").Accepts(AcceptedCharactersInternal.WhiteSpace)));
Factory.Markup("<!--F> Qux")));
}
[Fact]