public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
{
if (output.TagMode == TagMode.SelfClosing && AspFor == null)
{
throw new InvalidOperationException(
$"Content is required when the '{AspForAttributeName}' attribute is not specified.");
}
var errorSummaryContext = (ErrorSummaryContext)context.Items[typeof(ErrorSummaryContext)];
var childContent = await output.GetChildContentAsync();
IHtmlContent itemContent;
if (output.TagMode == TagMode.StartTagAndEndTag)
{
itemContent = childContent.Snapshot();
}
else
{
var validationMessage = _modelHelper.GetValidationMessage(
ViewContext,
AspFor.ModelExplorer,
AspFor.Name);
if (validationMessage == null)
{
return;
}
itemContent = new HtmlString(validationMessage);
}
// If there are link attributes or AspFor specified then wrap content in a link
if (For != null || AspFor != null)
{
var resolvedHref = For != null ?
"#" + For :
"#" + TagBuilder.CreateSanitizedId(
_modelHelper.GetFullHtmlFieldName(ViewContext, AspFor.Name),
Constants.IdAttributeDotReplacement);
var link = new TagBuilder("a");
link.Attributes.Add("href", resolvedHref);
link.InnerHtml.AppendHtml(itemContent);
itemContent = link;
}
errorSummaryContext.AddItem(new ErrorSummaryItem()
{
Content = itemContent,
Attributes = output.Attributes.ToAttributesDictionary()
});
output.SuppressOutput();
}
public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
{
var childContent = output.TagMode == TagMode.StartTagAndEndTag ?
await output.GetChildContentAsync()
: null;
if (childContent == null && AspFor == null)
{
throw new InvalidOperationException($"Cannot determine content.");
}
var resolvedContent = (IHtmlContent)childContent;
if (resolvedContent == null && AspFor != null)
{
var validationMessage = _modelHelper.GetValidationMessage(
ViewContext,
AspFor.ModelExplorer,
AspFor.Name);
if (validationMessage != null)
{
resolvedContent = new HtmlString(validationMessage);
}
}
if (resolvedContent != null)
{
var tagBuilder = _htmlGenerator.GenerateErrorMessage(
VisuallyHiddenText,
Id,
resolvedContent,
output.Attributes.ToAttributesDictionary());
output.TagName = tagBuilder.TagName;
output.TagMode = TagMode.StartTagAndEndTag;
output.Attributes.Clear();
output.MergeAttributes(tagBuilder);
output.Content.SetHtmlContent(tagBuilder.InnerHtml);
}
else
{
output.SuppressOutput();
}
}