private void UpdateHash(FileVersionHash withHash, IEnumerable <IFileProvider> fileProviders)
{
if (this.HashType != withHash)
{
this.HashType = withHash;
switch (this.HashType)
{
case FileVersionHash.FileHash:
var file = fileProviders.Select(x => x.GetFileInfo(this.webRootRelativePath)).FirstOrDefault(x => x.Exists);
if (file == null)
{
throw new Exception($"Script file {this.webRootRelativePath} could not be found!");
}
using (var md5 = System.Security.Cryptography.MD5.Create())
using (var fileStream = file.CreateReadStream())
{
var hash = md5.ComputeHash(fileStream);
this.FileHash = BitConverter.ToString(hash).Replace("-", "").ToLowerInvariant();
}
break;
case FileVersionHash.Random:
this.FileHash = new Random().Next().ToString();
break;
case FileVersionHash.None:
this.FileHash = "";
break;
}
}
}
public HtmlString Render(string staticRoot, IEnumerable <IFileProvider> fileProviders, FileVersionHash withHash = FileVersionHash.None)
{
string hash = "";
this.UpdateHash(withHash, fileProviders);
if (withHash != FileVersionHash.None)
{
hash = $"?hash={this.FileHash}";
}
return(new HtmlString($"<link href=\"{staticRoot.TrimEnd('/')}/{this.webRootRelativePath.TrimStart('~', '/')}{hash}\" rel=\"stylesheet\" media=\"{this.MediaQuery}\" />"));
}
