/// <summary>
/// Checks all attributes on a tag-helper element if any are asp-all-route-data or asp-route-*
/// Returns null if no route data was found.
/// </summary>
/// <param name="attributes"></param>
/// <returns></returns>
public static Dictionary <string, string> GetRouteValues(ReadOnlyTagHelperAttributeList attributes)
{
bool hasAllRouteData = attributes.TryGetAttribute("asp-all-route-data", out TagHelperAttribute allRouteValues);
if (hasAllRouteData)
{
return(allRouteValues.Value as Dictionary <string, string>);
}
else
{
// You can write the attributes as ASP-ROUTE- and the name will be ASP-ROUTE so need to ignore case
IEnumerable <TagHelperAttribute> routeAttributes = attributes.Where(x => x.Name.StartsWith("asp-route-", StringComparison.OrdinalIgnoreCase));
if (routeAttributes.Any())
{
Dictionary <string, string> routeValues = new Dictionary <string, string>();
foreach (TagHelperAttribute attribute in routeAttributes)
{
// asp-route- is 10 characters long
string parameter = attribute.Name.Substring(10).ToLower();
routeValues.Add(parameter, attribute.Value as string);
}
return(routeValues);
}
}
return(null);
}
public static TagHelperAttribute GetTagHelperAttribute(this ReadOnlyTagHelperAttributeList tagHelperAttribute, string name)
{
if (tagHelperAttribute.TryGetAttribute(name, out var attribute))
{
return(attribute);
}
return(null);
}
private static bool HasMissingAttributes(ReadOnlyTagHelperAttributeList allAttributes, string[] requiredAttributes)
{
// Check for all attribute values
// Perf: Avoid allocating enumerator
for (var i = 0; i < requiredAttributes.Length; i++)
{
if (!allAttributes.TryGetAttribute(requiredAttributes[i], out var attribute))
{
// Missing attribute.
return(true);
}
if (attribute.Value is string valueAsString && string.IsNullOrEmpty(valueAsString))
{
// Treat attributes with empty values as missing.
return(true);
}
}
return(false);
}