File Uploader

Last modified: March 17, 2026

Introduction

The File Uploader enables you to upload files or images by dragging and dropping them onto the widget, or by using the file selection dialog box.

It supports multi-file uploading, and includes an image-only mode that previews thumbnails of the uploaded images. The module comes with a domain model containing the entities and nanoflows it needs to function properly.

Setup

Read below for either simple setup instructions, or a more advanced setup (needed when modifying the context entity is not possible).

In the following sections, the term "context entity" refers to the entity of the context object in which the file uploader widget is placed. This can be either a data view or a page parameter.

Simple Setup

For a simple setup, the context entity needs to be a specialization of the FileUploader.FileUploadContext entity. This allows you to use the nanoflows and entities provided with the module:

In your domain model:
1. Set the generalization of the context entity to FileUploader.FileUploadContext.
On your page:
1. Place the FileUploader widget.
2. Set the Associated files property to FileUploader.UploadedFile or FileUploader.UploadedImage, depending on the upload mode.
3. Set the Action to create new files property to one of the nanoflows shipped with the module, depending on the upload mode.

Starting with File Uploader 2.0, the widget properties will be set automatically.

Advanced Setup

For an advanced setup, useful when modifying the context entity is not possible, follow these steps:

In your domain model:
1. Create a new specialized image/file entity by setting its generalization to System.FileDocument or System.Image, depending on the upload mode.
2. Create a many-to-one association from this image/file entity to your context entity.
In the App Explorer / Logic Editor:
1. Copy one of the two nanoflows (depending on the upload mode) from the module and modify it to use your context entity and the newly created file/image entity.
On your page:
1. Place the FileUploader widget.
2. Set the widget property Associated files to the newly created file/image entity.
3. Set the widget property Action to create new files to the modified nanoflow.

General Tab

Upload Mode

Files — Allows all file types by default, and adds a configuration option to specify a custom set of allowed file types.
Images — Limits uploads to images and shows a preview thumbnail.

Associated Files / Associated Images

Defines the entity which is used to store the files or images. Needs to be a specialization of System.FileDocument or System.Image.
By default, use FileUploader.UploadedFile for upload mode Files and FileUploader.UploadedImage for upload mode Images.

Action to Create New Files

Configuration to set up the nanoflow which creates an associated file object and commits it.
By default, calls Nanoflow ACT_CreateUploadedFileDocument for a Files upload mode and ACT_CreateUploadedImageDocument for an Images upload mode.

Allowed File Format

This configuration is only shown for the Files upload mode. Users can manually set restrictions on the allowed file types.

Maximum Number of Files

This configuration sets a limit on how many files can be uploaded in total.

Maximum File Size (MB)

This configuration sets a maximum limit on the file size of uploaded files.

Text Tab

Configures the displayed text used in File Uploader.

Advanced Tab

Object Creation Timeout

Configures the timeout to wait until object creation has failed. The value is in seconds.

On Upload Success

This action runs after a successful upload. When uploading multiple files at once, it will run for every successfully uploaded file, and this file will be passed as an argument to the action.

On Upload Failure

This action runs when an upload to the server started, but failed during the process. The created object will be passed to the action. This is useful to perform cleanups from empty, dangling objects that were created but did not have content uploaded to them.

This action will not run if a validation error occurred on the client side, for example, if a provided file was too big or had an incorrect extension.

Enable Custom Buttons

Allows the use of custom action buttons that will be displayed on the right side of the file list instead of the standard buttons. If set to Yes, the default action buttons will be hidden.

Custom Buttons

Adds custom buttons that will be used in the file uploader:

Caption — Caption text configuration for the custom button.
Icon — Provides icon configuration for the custom button.
Action — Provides On click action configuration for the custom button.
Default file action — If set to Yes, the action in the button will be used as the default click action for the file.
Visible — If set to False, the button will be hidden.

Nanoflows

This module includes two predefined nanoflows:

ACT_CreateUploadedFileDocument

This nanoflow will attach an uploaded file to the context object.

ACT_CreateUploadedImageDocument

This nanoflow will attach an uploaded image to the context object.