Connected.Components/Components/FileUpload/FileUpload.razor.cs

// Copyright (c) MudBlazor 2021
// MudBlazor licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using Connected.Annotations;
using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Components.Forms;
using Microsoft.Extensions.Logging;
using Connected.Utilities;

namespace Connected.Components;

public partial class FileUpload<T> : FormComponent<T, string>
{
   public FileUpload() : base(new DefaultConverter<T>()) { }

   private readonly string _id = $"mud_fileupload_{Guid.NewGuid()}";

   protected string Classname =>
      new CssBuilder("mud-file-upload")
      .AddClass(Class)
      .Build();

   /// <summary>
   /// The value of the MudFileUpload component.
   /// If T is <see cref="IBrowserFile">IBrowserFile</see>, it represents a single file.
   /// If T is <see cref="IReadOnlyCollection{IBrowserFile}">IReadOnlyList&lt;IBrowserFile&gt;</see>, it represents multiple files
   /// </summary>
   [Parameter]
   [Category(CategoryTypes.FileUpload.Behavior)]
   public T Files
   {
      get => _value;
      set
      {
         if (_value != null && _value.Equals(value))
            return;
         _value = value;
      }
   }
   /// <summary>
   /// Triggered when the internal OnChange event fires
   /// </summary>
   [Parameter]
   [Category(CategoryTypes.FileUpload.Behavior)]
   public EventCallback<T> FilesChanged { get; set; }

   /// <summary>
   /// Called when the internal files are changed
   /// </summary>
   [Parameter]
   [Category(CategoryTypes.FileUpload.Behavior)]
   public EventCallback<InputFileChangeEventArgs> OnFilesChanged { get; set; }
   /// <summary>
   /// Renders the button that triggers the input. Required for functioning.
   /// </summary>
   [Parameter]
   [Category(CategoryTypes.FileUpload.Appearance)]
   public RenderFragment<string> ButtonTemplate { get; set; }
   /// <summary>
   /// Renders the selected files, if desired.
   /// </summary>
   [Parameter]
   [Category(CategoryTypes.FileUpload.Appearance)]
   public RenderFragment<T> SelectedTemplate { get; set; }
   /// <summary>
   /// If true, OnFilesChanged will not trigger if validation fails
   /// </summary>
   [Parameter]
   [Category(CategoryTypes.FileUpload.Behavior)]
   public bool SuppressOnChangeWhenInvalid { get; set; }
   /// <summary>
   /// Sets the file types this input will accept
   /// </summary>
   [Parameter]
   [Category(CategoryTypes.FileUpload.Behavior)]
   public string Accept { get; set; }
   /// <summary>
   /// If false, the inner FileInput will be visible
   /// </summary>
   [Parameter]
   [Category(CategoryTypes.FileUpload.Appearance)]
   public bool Hidden { get; set; } = true;
   /// <summary>
   /// Css classes to apply to the internal InputFile
   /// </summary>
   [Parameter]
   [Category(CategoryTypes.FileUpload.Appearance)]
   public string InputClass { get; set; }
   /// <summary>
   /// Style to apply to the internal InputFile
   /// </summary>
   [Parameter]
   [Category(CategoryTypes.FileUpload.Appearance)]
   public string InputStyle { get; set; }

   private async Task OnChange(InputFileChangeEventArgs args)
   {
      if (typeof(T) == typeof(IReadOnlyList<IBrowserFile>))
      {
         _value = (T)args.GetMultipleFiles();
      }
      else if (typeof(T) == typeof(IBrowserFile))
      {
         _value = (T)args.File;
      }
      else return;

      await FilesChanged.InvokeAsync(_value);
      BeginValidate();
      FieldChanged(_value);
      if (!Error || !SuppressOnChangeWhenInvalid) //only trigger FilesChanged if validation passes or SuppressOnChangeWhenInvalid is false
         await OnFilesChanged.InvokeAsync(args);
   }

   protected override void OnInitialized()
   {
      if (!(typeof(T) == typeof(IReadOnlyList<IBrowserFile>) || typeof(T) == typeof(IBrowserFile)))
         Logger.LogWarning("T must be of type {type1} or {type2}", typeof(IReadOnlyList<IBrowserFile>), typeof(IBrowserFile));

      base.OnInitialized();
   }
}