Demonstration code for Preprocessing uploaded images with Umbraco

ImageProcessorPreProcessor.cs

// --------------------------------------------------------------------------------------------------------------------
// <copyright file="ImageProcessorPreProcessor.cs" company="James Jackson-South">
//   Copyright (c) James Jackson-South.
//   Licensed under the Apache License, Version 2.0.
// </copyright>
// <summary>
//   Attaches ImageProcessor to the Media.Saving event to ensure that uploaded files do not exceed
//   a maximum size.
// </summary>
// --------------------------------------------------------------------------------------------------------------------

namespace CodeGardenDemo.Events
{
    using System;
    using System.Collections.Generic;
    using System.Drawing;
    using System.IO;
    using System.Linq;
    using System.Web.Helpers;

    using ImageProcessor;
    using ImageProcessor.Imaging;

    using Umbraco.Core;
    using Umbraco.Core.Configuration;
    using Umbraco.Core.Configuration.UmbracoSettings;
    using Umbraco.Core.IO;
    using Umbraco.Core.Logging;
    using Umbraco.Core.Models;
    using Umbraco.Core.Services;

    /// <summary>
    /// Attaches ImageProcessor to the Media.Saving event to ensure that uploaded files do not exceed
    /// a maximum size.
    /// </summary>
    public class ImageProcessorPreProcessor : ApplicationEventHandler
    {
        /// <summary>
        /// Overridable method to execute when All resolvers have been initialized but resolution is not 
        /// frozen so they can be modified in this method
        /// </summary>
        /// <param name="umbracoApplication">The current <see cref="UmbracoApplicationBase"/></param>
        /// <param name="applicationContext">The Umbraco <see cref="ApplicationContext"/> for the current application.</param>
        protected override void ApplicationStarting(UmbracoApplicationBase umbracoApplication, ApplicationContext applicationContext)
        {
            const string UmbracoFile = Constants.Conventions.Media.File;

            // Tap into the Saved event
            MediaService.Saved += (sender, args) =>
            {
                MediaFileSystem mediaFileSystem = FileSystemProviderManager.Current.GetFileSystemProvider<MediaFileSystem>();
                IContentSection contentSection = UmbracoConfig.For.UmbracoSettings().Content;
                IEnumerable<string> supportedTypes = contentSection.ImageFileTypes.ToList();

                foreach (IMedia media in args.SavedEntities)
                {
                    if (media.HasProperty(UmbracoFile))
                    {
                        string path = media.GetValue<string>(UmbracoFile);

                        try
                        {
                            // Make sure it's not empty.
                            if (string.IsNullOrWhiteSpace(path))
                            {
                                return;
                            }

                            // This might happen after changing the data type of umbracoFile from 
                            // Image Cropper back to Upload. 
                            if (path.Contains("{"))
                            {
                                dynamic cropper = Json.Decode(path);
                                string src = cropper.Src;
                                if (!string.IsNullOrWhiteSpace(src))
                                {
                                    path = src;
                                }
                                else
                                {
                                    return;
                                }
                            }

                            // Make sure it's an image.
                            string extension = Path.GetExtension(path).Substring(1);
                            if (supportedTypes.InvariantContains(extension))
                            {
                                // Resize the image, height is driven by the
                                // aspect ratio of the image.
                                string fullPath = mediaFileSystem.GetFullPath(path);
                                using (ImageFactory imageFactory = new ImageFactory(true))
                                {
                                    // Hardcoded at 1920 but could be configurable.
                                    ResizeLayer layer = new ResizeLayer(new Size(1920, 0), ResizeMode.Max)
                                    {
                                        Upscale = false
                                    };

                                    // Resize
                                    imageFactory.Load(fullPath).Resize(layer);

                                    int newWidth = imageFactory.Image.Width;
                                    int newHeight = imageFactory.Image.Height;

                                    // Save
                                    imageFactory.Save(fullPath);

                                    FileInfo info = new FileInfo(fullPath);
                                    long bytes = info.Length;

                                    // Set the correct meta values for the image.
                                    media.SetValue(Constants.Conventions.Media.Width, newWidth);
                                    media.SetValue(Constants.Conventions.Media.Height, newHeight);
                                    media.SetValue(Constants.Conventions.Media.Bytes, bytes);
                                    sender.Save(media, 0, false);
                                }
                            }
                        }
                        catch (Exception ex)
                        {
                            // For all unexpected errors we get a hint in the log file.
                            LogHelper.Error<ImageProcessorPreProcessor>(
                                string.Format("Could not resize image. Path: {0}", path), ex);
                        }
                    }
                }
            };
        }
    }
}

Note This needs splitting up into separate events to work correctly with Azure.

@JimBobSquarePants Firstly thanks for sharing this 👍 I'm currently having an issue which is probably related to your comment above. I'm trying to use this along side your AzureBlobStorage file provider, however, it currently errors when trying to load/save the image using the ImageFactory. Do you have any pointers on what might need changing for it to work with blob storage? Cheers

Hi, I'm having the same issue.. do you have any suggestions?