// We don't want to classify TagNames of well-known HTML
// elements as TagHelpers (even if they are). So the 'input' in`<input @onclick='...' />`
// needs to not be marked as a TagHelper, but `<Input @onclick='...' />` should be.
private bool ClassifyTagName(MarkupTagHelperElementSyntax node)
{
if (node is null)
{
throw new ArgumentNullException(nameof(node));
}
if (node.StartTag != null && node.StartTag.Name != null)
{
var name = node.StartTag.Name.Content;
if (!HtmlFactsService.IsHtmlTagName(name))
{
// We always classify non-HTML tag names as TagHelpers if they're within a MarkupTagHelperElementSyntax
return(true);
}
// This must be a well-known HTML tag name like 'input', 'br'.
var binding = node.TagHelperInfo.BindingResult;
foreach (var descriptor in binding.Descriptors)
{
if (!descriptor.IsComponentTagHelper())
{
return(false);
}
}
if (name.Length > 0 && char.IsUpper(name[0]))
{
// pascal cased Component TagHelper tag name such as <Input>
return(true);
}
}
return(false);
}
private IReadOnlyList <RazorCompletionItem> GetAttributeCompletions(
SyntaxNode containingAttribute,
string containingTagName,
string?selectedAttributeName,
IEnumerable <KeyValuePair <string, string> > attributes,
TagHelperDocumentContext tagHelperDocumentContext,
RazorCompletionOptions options)
{
var ancestors = containingAttribute.Parent.Ancestors();
var nonDirectiveAttributeTagHelpers = tagHelperDocumentContext.TagHelpers.Where(tagHelper => !tagHelper.BoundAttributes.Any(attribute => attribute.IsDirectiveAttribute()));
var filteredContext = TagHelperDocumentContext.Create(tagHelperDocumentContext.Prefix, nonDirectiveAttributeTagHelpers);
var(ancestorTagName, ancestorIsTagHelper) = _tagHelperFactsService.GetNearestAncestorTagInfo(ancestors);
var attributeCompletionContext = new AttributeCompletionContext(
filteredContext,
existingCompletions: Enumerable.Empty <string>(),
containingTagName,
selectedAttributeName,
attributes,
ancestorTagName,
ancestorIsTagHelper,
HtmlFactsService.IsHtmlTagName);
var completionItems = new List <RazorCompletionItem>();
var completionResult = _tagHelperCompletionService.GetAttributeCompletions(attributeCompletionContext);
foreach (var completion in completionResult.Completions)
{
var filterText = completion.Key;
// This is a little bit of a hack because the information returned by _razorTagHelperCompletionService.GetAttributeCompletions
// does not have enough information for us to determine if a completion is an indexer completion or not. Therefore we have to
// jump through a few hoops below to:
// 1. Determine if this specific completion is an indexer based completion
// 2. Resolve an appropriate snippet if it is. This is more troublesome because we need to remove the ... suffix to accurately
// build a snippet that makes sense for the user to type.
var indexerCompletion = filterText.EndsWith("...", StringComparison.Ordinal);
if (indexerCompletion)
{
filterText = filterText.Substring(0, filterText.Length - 3);
}
var attributeContext = ResolveAttributeContext(completion.Value, indexerCompletion, options.SnippetsSupported);
var attributeCommitCharacters = ResolveAttributeCommitCharacters(attributeContext);
var isSnippet = false;
var insertText = filterText;
if (TryResolveInsertText(insertText, attributeContext, out var snippetText))
{
isSnippet = true;
insertText = snippetText;
}
// We change the sort text depending on the tag name due to TagHelper/non-TagHelper concerns. For instance lets say you have a TagHelper that binds to `input`.
// Chances are you're expecting to get every other `input` completion item in addition to the TagHelper completion items and the sort order should be the default
// because HTML completion items are 100% as applicable as other items.
//
// Next assume that we have a TagHelper that binds `custom` (or even `Custom`); this is a special scenario where the user has effectively created a new HTML tag
// meaning they're probably expecting to provide all of the attributes necessary for that tag to operate. Meaning, HTML attribute completions are less important.
// To make sure we prioritize our attribute completions above all other types of completions we set the priority to high so they're showed in the completion list
// above all other completion items.
var sortText = HtmlFactsService.IsHtmlTagName(containingTagName) ? CompletionSortTextHelper.DefaultSortPriority : CompletionSortTextHelper.HighSortPriority;
var razorCompletionItem = new RazorCompletionItem(
displayText: completion.Key,
insertText: insertText,
sortText: sortText,
kind: RazorCompletionItemKind.TagHelperAttribute,
commitCharacters: attributeCommitCharacters,
isSnippet: isSnippet);
var attributeDescriptions = completion.Value.Select(boundAttribute =>
{
var descriptionInfo = BoundAttributeDescriptionInfo.From(boundAttribute, indexerCompletion);
return(descriptionInfo);
});
var attributeDescriptionInfo = new AggregateBoundAttributeDescription(attributeDescriptions.ToList());
razorCompletionItem.SetAttributeCompletionDescription(attributeDescriptionInfo);
completionItems.Add(razorCompletionItem);
}
return(completionItems);
}