private void ValidateParentAllowsPlainStartTag(MarkupStartTagSyntax tagBlock)
{
var tagName = tagBlock.GetTagNameWithOptionalBang();
// Treat partial tags such as '</' which have no tag names as content.
if (string.IsNullOrEmpty(tagName))
{
var firstChild = tagBlock.Children.First();
Debug.Assert(firstChild is MarkupTextLiteralSyntax);
ValidateParentAllowsContent(firstChild);
return;
}
if (!HasAllowedChildren())
{
return;
}
var tagHelperBinding = _tagHelperBinder.GetBinding(
tagName,
attributes: Array.Empty <KeyValuePair <string, string> >(),
parentTagName: CurrentParentTagName,
parentIsTagHelper: CurrentParentIsTagHelper);
// If we found a binding for the current tag, then it is a tag helper. Use the prefixed allowed children to compare.
var allowedChildren = tagHelperBinding != null ? CurrentTagHelperTracker.PrefixedAllowedChildren : CurrentTagHelperTracker.AllowedChildren;
if (!allowedChildren.Contains(tagName, StringComparer.OrdinalIgnoreCase))
{
OnAllowedChildrenStartTagError(CurrentTagHelperTracker, tagName, tagBlock, _errorSink, _source);
}
}
private bool TryRewriteTagHelperStart(
MarkupStartTagSyntax startTag,
MarkupEndTagSyntax endTag,
out MarkupTagHelperStartTagSyntax rewritten,
out TagHelperInfo tagHelperInfo)
{
rewritten = null;
tagHelperInfo = null;
// Get tag name of the current block
var tagName = startTag.GetTagNameWithOptionalBang();
// Could not determine tag name, it can't be a TagHelper, continue on and track the element.
if (string.IsNullOrEmpty(tagName) || tagName.StartsWith("!", StringComparison.Ordinal))
{
return(false);
}
TagHelperBinding tagHelperBinding;
if (!IsPotentialTagHelperStart(tagName, startTag))
{
return(false);
}
var tracker = CurrentTagHelperTracker;
var tagNameScope = tracker?.TagName ?? string.Empty;
// We're now in a start tag block, we first need to see if the tag block is a tag helper.
var elementAttributes = GetAttributeNameValuePairs(startTag);
tagHelperBinding = _tagHelperBinder.GetBinding(
tagName,
elementAttributes,
CurrentParentTagName,
CurrentParentIsTagHelper);
// If there aren't any TagHelperDescriptors registered then we aren't a TagHelper
if (tagHelperBinding == null)
{
// If the current tag matches the current TagHelper scope it means the parent TagHelper matched
// all the required attributes but the current one did not; therefore, we need to increment the
// OpenMatchingTags counter for current the TagHelperBlock so we don't end it too early.
// ex: <myth req="..."><myth></myth></myth> We don't want the first myth to close on the inside
// tag.
if (string.Equals(tagNameScope, tagName, StringComparison.OrdinalIgnoreCase))
{
tracker.OpenMatchingTags++;
}
return(false);
}
ValidateParentAllowsTagHelper(tagName, startTag);
ValidateBinding(tagHelperBinding, tagName, startTag);
// We're in a start TagHelper block.
ValidateStartTagSyntax(tagName, startTag);
var rewrittenStartTag = TagHelperBlockRewriter.Rewrite(
tagName,
_featureFlags,
startTag,
tagHelperBinding,
_errorSink,
_source);
var tagMode = TagHelperBlockRewriter.GetTagMode(startTag, endTag, tagHelperBinding);
tagHelperInfo = new TagHelperInfo(tagName, tagMode, tagHelperBinding);
rewritten = rewrittenStartTag;
return(true);
}