internal void AddTransformChain(AssetFileExtension assetFileExtension, params Type[] transforms)
{
if (null == assetFileExtension)
{
throw new ArgumentNullException(nameof(assetFileExtension));
}
if (null == transforms || 0 == transforms.Length)
{
throw new ArgumentException($"No transforms specified for the predicate.");
}
Type typeOfITransform = typeof(ITransform);
if (!transforms.Any(t => typeOfITransform.IsAssignableFrom(t)))
{
throw new InvalidCastException("All transform types must implement the interface ITransform.");
}
if (transforms.Any(t => !t.IsClass || t.IsAbstract || !t.IsPublic))
{
throw new InvalidCastException("All transform types must be concrete public classes.");
}
this.TransformChains[assetFileExtension] = transforms.ToList(); // calling this method for the same key will overwrite the existing chain
}
public async Task <OptimizationResult> OptimizeAsync(IOptimizationContext context, AssetFileExtension assetFileExtension)
{
if (null == assetFileExtension)
{
assetFileExtension = string.Empty;
}
if (!context.Assets.Any())
{
return(OptimizationResult.Empty);
}
var orderedAssets = this.Orderer.Order(context.Assets.Where(a => 0 == string.Compare(Path.GetExtension(a.Location.ToString()), assetFileExtension, StringComparison.OrdinalIgnoreCase)));
foreach (var asset in orderedAssets)
{
bool isAssetLoaded = false;
foreach (var loader in this.Loaders)
{
if (loader.CanLoad(asset))
{
this.Logger.LogTrace($"Loading asset '{asset.Location}' using '{nameof(loader)}'.");
using (var stream = await loader.OpenReadStreamAsync(asset))
{
await asset.SetContentAsync(stream);
isAssetLoaded = true;
}
break;
}
}
if (!isAssetLoaded)
{
throw new InvalidOperationException($"Couldn't find an asset loader to load the asset from '{asset.Location}'.");
}
}
IEnumerable <Asset> assets = orderedAssets;
foreach (var transformPair in this.TransformChains.Where(x => 0 == string.Compare(x.Key, assetFileExtension, StringComparison.OrdinalIgnoreCase)))
{
foreach (ITransform transform in transformPair.Value)
{
if (null == this.Events?.TransformRunning || this.Events.TransformRunning.Invoke(assetFileExtension, this.Options, transform))
{
var inputAssets = assets.ToArray();
assets = await transform.TransformAsync(assetFileExtension, inputAssets);
await transform.CleanUpAsync(inputAssets);
}
}
break;
}
var optimizationResult = new OptimizationResult();
await optimizationResult.InitializeAsync(assets);
return(optimizationResult);
}
