Use case: Replace uploaded file content

You can use the Unity Cloud Assets package to upload new content for a file.

Note

Once a file is uploaded, its content cannot be modified. If you want to change the content of a file, you must:

1. Remove all references to this file, effectively deleting it.
2. You may upload a new file with the same name.

The SDK supports different workflows for users with different roles.

Organization or Asset Manager Project role	Upload file content
Asset Management Viewer	no
Asset Management Consumer	no
Asset Management Contributor	yes
Organization Owner	yes

Before you start

Before you start, you must:

1. Set up a Unity scene in the Unity Editor with an Organization and Project browser. See Get started with Assets for more information.

2. Have some assets in the cloud. There are several ways to do so:

   • You can create assets through the Get started with Assets.
   • You can create assets through the dashboard, see the Managing assets on the dashboard documentation.

You should also have uploaded files to an asset, see the Create files use case.

How do I...?

List the files of an asset

If you have not already done so, you must update the behaviour to get the list of files for an asset.

See the Use case: Update an asset's files documentation for more information.

Replace a file

To replace the content of a file, follow these steps:

1. Open the AssetManagementBehaviour script you created.
2. Add the following code to the end of the class:

CancellationTokenSource m_FileUploadCancellationSource;

public async Task ReplaceFileAsync(IFile file, MemoryStream memoryStream)
{
    await file.UploadAsync(memoryStream, new LogProgress(file.Descriptor.Path), GetCancellationToken());
}

CancellationToken GetCancellationToken()
{
    if (m_FileUploadCancellationSource != null)
    {
        m_FileUploadCancellationSource.Cancel();
        m_FileUploadCancellationSource.Dispose();
    }

    m_FileUploadCancellationSource = new CancellationTokenSource();
    return m_FileUploadCancellationSource.Token;
}

The code snippet does the following:

• Removes the file from each dataset it is referenced in.
• Creates and uploads the file as a new file to one of the datasets.
• Adds a reference to the new file in each dataset the old file was referenced in.

Add the UI for re-uploading file content

To create UI for re-uploading file content, follow these steps:

1. In your Unity Project window, go to Assets > Scripts.
2. Select and hold the Assets/Scripts folder.
3. Go to Create > C# Script. Name your script UseCaseFileReuploadExampleUI.
4. Open the UseCaseFileReuploadExampleUI script you created and replace the contents of the file with the following code sample:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Unity.Cloud.Assets;
using Unity.Cloud.Common;
using UnityEngine;

public class UseCaseFileReuploadExampleUI : IAssetManagementUI
{
    readonly BaseAssetBehaviour m_Behaviour;

    public UseCaseFileReuploadExampleUI(BaseAssetBehaviour behaviour)
    {
        m_Behaviour = behaviour;
    }

    public void OnGUI() { }
}

5. In the same script, replace the OnGUI function with the following code:

        IAsset m_CurrentAsset;

        Dictionary<DatasetId, bool> m_Expanded = new();

        public void OnGUI()
        {
            if (m_Behaviour.CurrentAsset == null) return;

            if (m_CurrentAsset != m_Behaviour.CurrentAsset)
            {
                m_CurrentAsset = m_Behaviour.CurrentAsset;
                m_Behaviour.DatasetFiles.Clear();
                _ = m_Behaviour.GetDatasets();
            }

            if (m_Behaviour.Datasets == null)
            {
                GUILayout.Label("Loading datasets...");
                return;
            }

            GUILayout.BeginVertical();

            if (GUILayout.Button("Refresh", GUILayout.Width(60)))
            {
                _ = m_Behaviour.GetDatasets();
            }

            GUILayout.Space(5f);

            DisplayDatasets(m_Behaviour.Datasets.ToArray());

            GUILayout.EndVertical();
        }

        void DisplayDatasets(IReadOnlyCollection<IDataset> datasets)
        {
            if (datasets.Count == 0)
            {
                GUILayout.Label("No datasets.");
            }

            foreach (var dataset in datasets)
            {
                var datasetId = dataset.Descriptor.DatasetId;

                GUILayout.BeginHorizontal();

                GUILayout.Label(m_Behaviour.GetDatasetName(datasetId));

                var expanded = m_Expanded.GetValueOrDefault(datasetId);
                if (GUILayout.Button(expanded ? "-" : "+", GUILayout.Width(20f)))
                {
                    expanded = !expanded;
                    m_Expanded[datasetId] = expanded;

                    if (!expanded)
                    {
                        m_Behaviour.DatasetFiles.Remove(datasetId);
                    }
                }

                GUILayout.EndHorizontal();

                if (expanded)
                {
                    GUILayout.BeginHorizontal();

                    GUILayout.Space(25);

                    DisplayFiles(datasetId);

                    GUILayout.EndHorizontal();
                }
            }
        }

        void DisplayFiles(DatasetId datasetId)
        {
            if (!m_Behaviour.DatasetFiles.ContainsKey(datasetId))
            {
                _ = m_Behaviour.GetFilesAsync(datasetId);
            }

            var files = m_Behaviour.DatasetFiles.GetValueOrDefault(datasetId);

            if (files == null)
            {
                GUILayout.Label("Loading files...");
                return;
            }

            var enumerable = files.ToArray();
            if (!enumerable.Any())
            {
                GUILayout.Label("No files.");
                return;
            }

            GUILayout.BeginVertical();

            foreach (var file in enumerable)
            {
                GUILayout.BeginHorizontal();

                GUILayout.Label($"{file.Descriptor.Path}");

                GUILayout.Space(5f);

                if (GUILayout.Button("Upload new content", GUILayout.Width(150)))
                {
#if UNITY_EDITOR
                    var path = UnityEditor.EditorUtility.OpenFilePanel("Choose a file to upload.", Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), "");
                    if (!string.IsNullOrEmpty(path))
                    {
                        var memoryStream = new MemoryStream(File.ReadAllBytes(path));
                        _ = m_Behaviour.ReplaceFileAsync(file, memoryStream);
                    }
#else
                    Debug.Log("Feature only supported in Editor.");
#endif
                }

                GUI.enabled = true;

                GUILayout.EndHorizontal();
            }

            GUILayout.EndVertical();
        }

6. Open the AssetManagementUI script you created and replace the contents of the Awake function with the following code:

m_UI.Add(new OrganizationSelectionExampleUI(m_Behaviour));
m_UI.Add(new ProjectSelectionExampleUI(m_Behaviour));
m_UI.Add(new AssetSelectionExampleUI(m_Behaviour));
m_UI.Add(new UseCaseFileReuploadExampleUI(m_Behaviour));

The script does the following:

• Displays a text field to enter a path to a file to upload.
• Displays a list of the selected asset's files with a button to replace the file.
• Displays a button to cancel the request once started.