public override async Task ProcessAsync(TagHelperContext context, TagHelperOutput output)
{
output.TagName = "img";
output.TagMode = TagMode.SelfClosing;
HttpClient httpClient = new HttpClient();
string fileUrl = "";
if (Src.StartsWith("http") || FallbackUrl.StartsWith("https"))
{
var webUrl = new Uri(Src);
httpClient.BaseAddress = new Uri($"{webUrl.Scheme}://{webUrl.Host}");
Src = webUrl.LocalPath;
}
else
{
var baseUrl = httpContextAccessor.HttpContext.Request.GetDisplayUrl();
httpClient.BaseAddress = new Uri(baseUrl);
}
using (HttpResponseMessage response = await httpClient.GetAsync(Src))
{
if (response.IsSuccessStatusCode)
{
output.Attributes.SetAttribute("src", Src);
}
else
{
output.Attributes.SetAttribute("src", FallbackUrl);
}
}
}
protected override void Render(HtmlTextWriter writer)
{
if (Src.StartsWith("~"))
{
Src = base.ResolveUrl(Src);
}
else if (Src.StartsWith("/"))
{
Src = GetImagePath() + Src;
}
else
{
Src = GetImagePath() + "/" + Src;
}
writer.Write(string.Format(CultureInfo.InvariantCulture, imageFormat, new object[] { Src }));
}