/// <summary>
/// Gets the base64 encoded string for the given icon resource url. This method has the potential to be very slow
/// as it will create a new resourceManager for a given assembly and search that assembly, which may require disk access.
/// </summary>
/// <param name="icon">Icon Url</param>
/// <param name="extension">Returns the extension to describe the type of resource.</param>
/// <returns>a base64 encoded string version of an image if found else null.</returns>
private string GetIconAsBase64(IconUrl icon, out string extension)
{
extension = "png";
var path = Path.GetFullPath(icon.Path); //Get full path if it's a relative path.
var libraryCustomization = getForAssemblyMethodInfo.Invoke(null, new object[] { path, pathManager, true });
if (libraryCustomization == null)
{
return(null);
}
var assembly = LibraryCustomizationResourceAssemblyProperty.GetValue(libraryCustomization) as Assembly;
if (assembly == null)
{
return(null);
}
// "Name" can be "Some.Assembly.Name.customization" with multiple dots,
// we are interested in removal of the "customization" part and the middle dots.
var temp = assembly.GetName().Name.Split('.');
var assemblyName = String.Join("", temp.Take(temp.Length - 1));
var rm = new ResourceManager(assemblyName + imagesSuffix, assembly);
using (var image = (Bitmap)rm.GetObject(icon.Name))
{
if (image == null)
{
return(null);
}
var tempstream = new MemoryStream();
image.Save(tempstream, image.RawFormat);
byte[] imageBytes = tempstream.ToArray();
tempstream.Dispose();
string base64String = Convert.ToBase64String(imageBytes);
return(base64String);
}
}
/// <summary>
/// Retrieves the resource for a given url as a base64 encoded string.
/// ie data:image/png;base64, stringxxxyyyzzz
/// </summary>
/// <param name="url">url for the requested icon</param>
/// <param name="extension">Returns the extension to describe the type of resource.</param>
/// <returns></returns>
public string GetResourceAsString(string url, out string extension)
{
//sometimes the urls have "about:" added to them - remove this
//and do it before checking cache.
//https://en.wikipedia.org/wiki/About_URI_scheme
if (url.StartsWith("about:"))
{
url = url?.Replace("about:", string.Empty);
}
if (!String.IsNullOrEmpty(url) && urlToBase64DataCache.ContainsKey(url))
{
var cachedData = urlToBase64DataCache[url];
extension = cachedData.Item2;
return(cachedData.Item1);
}
//because we modify the spec the icon urls may have been replaced by base64 encoded images
//if thats the case, no need to look them up again from disk, just return the string.
if (!String.IsNullOrEmpty(url) && url.Contains("data:image/"))
{
var match = Regex.Match(url, @"data:(?<type>.+?);base64,(?<data>.+)");
var base64Data = match.Groups["data"].Value;
var contentType = match.Groups["type"].Value;
//image/png -> png
extension = contentType.Split('/').Skip(1).FirstOrDefault();
urlToBase64DataCache.Add(url, Tuple.Create(base64Data, extension));
return(base64Data);
}
var base64String = string.Empty;
extension = "png";
//Create IconUrl to parse the request.Url to icon name and path.
if (String.IsNullOrEmpty(url))
{
return(string.Empty);
}
//before trying to create a uri we have to handle resources that might
//be embedded into the resources.dlls
//these paths will start with ./dist
if (url.StartsWith(@"./dist"))
{
//make relative url a full uri
var urlAbs = url.Replace(@"./dist", @"http://localhost/dist");
var ext = string.Empty;
var stream = embeddedDllResourceProvider.GetResource(urlAbs, out ext);
if (stream != null)
{
extension = ext;
base64String = GetIconAsBase64(stream, ext);
}
}
else
{
//TODO check if absolute instead of using try/catch
try
{
var icon = new IconUrl(new Uri(url));
base64String = GetIconAsBase64(icon, out extension);
}
catch (Exception)
{
//look in resources for registered path and just use the stream directly
var resourceDict = this.customization.Resources.ToDictionary(kvp => kvp.Key, kvp => kvp.Value);
if (resourceDict.ContainsKey(url))
{
var fileExtension = System.IO.Path.GetExtension(url);
extension = fileExtension;
base64String = GetIconAsBase64(resourceDict[url], fileExtension);
}
}
}
if (base64String == null)
{
base64String = GetDefaultIconBase64(out extension);
}
urlToBase64DataCache.Add(url, Tuple.Create(base64String, extension));
return(base64String);
}