Beispiel #1
0
        private static AttributeCompletionContext BuildAttributeCompletionContext(
            IEnumerable <TagHelperDescriptor> descriptors,
            IEnumerable <string> existingCompletions,
            string currentTagName,
            string currentAttributeName = null,
            IEnumerable <KeyValuePair <string, string> > attributes = null,
            string tagHelperPrefix = "")
        {
            attributes = attributes ?? Enumerable.Empty <KeyValuePair <string, string> >();
            var documentContext   = TagHelperDocumentContext.Create(tagHelperPrefix, descriptors);
            var completionContext = new AttributeCompletionContext(
                documentContext,
                existingCompletions,
                currentTagName,
                currentAttributeName,
                attributes,
                currentParentTagName: "body",
                currentParentIsTagHelper: false,
                inHTMLSchema: (tag) => tag == "strong" || tag == "b" || tag == "bold" || tag == "li" || tag == "div");

            return(completionContext);
        }
        /*
         * This API attempts to understand a users context as they're typing in a Razor file to provide TagHelper based attribute IntelliSense.
         *
         * Scenarios for TagHelper attribute IntelliSense follows:
         * 1. TagHelperDescriptor's have matching required attribute names
         *  -> Provide IntelliSense for the required attributes of those descriptors to lead users towards a TagHelperified element.
         * 2. TagHelperDescriptor entirely applies to current element. Tag name, attributes, everything is fulfilled.
         *  -> Provide IntelliSense for the bound attributes for the applied descriptors.
         *
         *  Within each of the above scenarios if an attribute completion has a corresponding bound attribute we associate it with the corresponding
         *  BoundAttributeDescriptor. By doing this a user can see what C# type a TagHelper expects for the attribute.
         */
        public override AttributeCompletionResult GetAttributeCompletions(AttributeCompletionContext completionContext)
        {
            if (completionContext == null)
            {
                throw new ArgumentNullException(nameof(completionContext));
            }

            var attributeCompletions = completionContext.ExistingCompletions.ToDictionary(
                completion => completion,
                _ => new HashSet <BoundAttributeDescriptor>(),
                StringComparer.OrdinalIgnoreCase);

            var documentContext   = completionContext.DocumentContext;
            var descriptorsForTag = _tagHelperFactsService.GetTagHelpersGivenTag(documentContext, completionContext.CurrentTagName, completionContext.CurrentParentTagName);

            if (descriptorsForTag.Count == 0)
            {
                // If the current tag has no possible descriptors then we can't have any additional attributes.
                var defaultResult = AttributeCompletionResult.Create(attributeCompletions);
                return(defaultResult);
            }

            var prefix = documentContext.Prefix ?? string.Empty;

            Debug.Assert(completionContext.CurrentTagName.StartsWith(prefix, StringComparison.OrdinalIgnoreCase));

            var applicableTagHelperBinding = _tagHelperFactsService.GetTagHelperBinding(
                documentContext,
                completionContext.CurrentTagName,
                completionContext.Attributes,
                completionContext.CurrentParentTagName,
                completionContext.CurrentParentIsTagHelper);

            var applicableDescriptors = applicableTagHelperBinding?.Descriptors ?? Enumerable.Empty <TagHelperDescriptor>();
            var unprefixedTagName     = completionContext.CurrentTagName.Substring(prefix.Length);

            if (!completionContext.InHTMLSchema(unprefixedTagName) &&
                applicableDescriptors.All(descriptor => descriptor.TagOutputHint == null))
            {
                // This isn't a known HTML tag and no descriptor has an output element hint. Remove all previous completions.
                attributeCompletions.Clear();
            }

            for (var i = 0; i < descriptorsForTag.Count; i++)
            {
                var descriptor = descriptorsForTag[i];

                if (applicableDescriptors.Contains(descriptor))
                {
                    foreach (var attributeDescriptor in descriptor.BoundAttributes)
                    {
                        UpdateCompletions(attributeDescriptor.Name, attributeDescriptor);
                    }
                }
                else
                {
                    var htmlNameToBoundAttribute = descriptor.BoundAttributes.ToDictionary(attribute => attribute.Name, StringComparer.OrdinalIgnoreCase);

                    foreach (var rule in descriptor.TagMatchingRules)
                    {
                        foreach (var requiredAttribute in rule.Attributes)
                        {
                            if (htmlNameToBoundAttribute.TryGetValue(requiredAttribute.Name, out var attributeDescriptor))
                            {
                                UpdateCompletions(requiredAttribute.Name, attributeDescriptor);
                            }
                            else
                            {
                                UpdateCompletions(requiredAttribute.Name, possibleDescriptor: null);
                            }
                        }
                    }
                }
            }

            var completionResult = AttributeCompletionResult.Create(attributeCompletions);

            return(completionResult);

            void UpdateCompletions(string attributeName, BoundAttributeDescriptor possibleDescriptor)
            {
                if (completionContext.Attributes.Any(attribute => string.Equals(attribute.Key, attributeName, StringComparison.OrdinalIgnoreCase)) &&
                    (completionContext.CurrentAttributeName == null ||
                     !string.Equals(attributeName, completionContext.CurrentAttributeName, StringComparison.OrdinalIgnoreCase)))
                {
                    // Attribute is already present on this element and it is not the attribute in focus.
                    // It shouldn't exist in the completion list.
                    return;
                }

                if (!attributeCompletions.TryGetValue(attributeName, out var rules))
                {
                    rules = new HashSet <BoundAttributeDescriptor>();
                    attributeCompletions[attributeName] = rules;
                }

                if (possibleDescriptor != null)
                {
                    rules.Add(possibleDescriptor);
                }
            }
        }
Beispiel #3
0
 public abstract AttributeCompletionResult GetAttributeCompletions(AttributeCompletionContext completionContext);