jellyfin/Jellyfin.Api/ModelBinders/PipeDelimitedArrayModelBinder.cs
2023-02-02 18:50:33 +01:00

90 lines
3.0 KiB
C#

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.Extensions.Logging;
namespace Jellyfin.Api.ModelBinders;
/// <summary>
/// Comma delimited array model binder.
/// Returns an empty array of specified type if there is no query parameter.
/// </summary>
public class PipeDelimitedArrayModelBinder : IModelBinder
{
private readonly ILogger<PipeDelimitedArrayModelBinder> _logger;
/// <summary>
/// Initializes a new instance of the <see cref="PipeDelimitedArrayModelBinder"/> class.
/// </summary>
/// <param name="logger">Instance of the <see cref="ILogger{PipeDelimitedArrayModelBinder}"/> interface.</param>
public PipeDelimitedArrayModelBinder(ILogger<PipeDelimitedArrayModelBinder> logger)
{
_logger = logger;
}
/// <inheritdoc/>
public Task BindModelAsync(ModelBindingContext bindingContext)
{
var valueProviderResult = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
var elementType = bindingContext.ModelType.GetElementType() ?? bindingContext.ModelType.GenericTypeArguments[0];
var converter = TypeDescriptor.GetConverter(elementType);
if (valueProviderResult.Length > 1)
{
var typedValues = GetParsedResult(valueProviderResult.Values, elementType, converter);
bindingContext.Result = ModelBindingResult.Success(typedValues);
}
else
{
var value = valueProviderResult.FirstValue;
if (value is not null)
{
var splitValues = value.Split('|', StringSplitOptions.RemoveEmptyEntries);
var typedValues = GetParsedResult(splitValues, elementType, converter);
bindingContext.Result = ModelBindingResult.Success(typedValues);
}
else
{
var emptyResult = Array.CreateInstance(elementType, 0);
bindingContext.Result = ModelBindingResult.Success(emptyResult);
}
}
return Task.CompletedTask;
}
private Array GetParsedResult(IReadOnlyList<string> values, Type elementType, TypeConverter converter)
{
var parsedValues = new object?[values.Count];
var convertedCount = 0;
for (var i = 0; i < values.Count; i++)
{
try
{
parsedValues[i] = converter.ConvertFromString(values[i].Trim());
convertedCount++;
}
catch (FormatException e)
{
_logger.LogDebug(e, "Error converting value.");
}
}
var typedValues = Array.CreateInstance(elementType, convertedCount);
var typedValueIndex = 0;
for (var i = 0; i < parsedValues.Length; i++)
{
if (parsedValues[i] != null)
{
typedValues.SetValue(parsedValues[i], typedValueIndex);
typedValueIndex++;
}
}
return typedValues;
}
}