#Office File Preview v1.8.11+

This feature is provided by the plugin «Office File Previewer»

The Office File Preview plugin allows users to preview Office-format files, such as Word, Excel, and PowerPoint, directly within the NocoBase application.
It leverages Microsoft's public online service to embed the file content into a preview interface, enabling users to view documents directly in the browser without downloading or using Office applications.

#User Guide

By default, this plugin is disabled. It can be enabled in the plugin manager and requires no additional configuration.

After successfully uploading an Office file (Word / Excel / PowerPoint) to a file field in a data table, you can click the file icon or link to preview its content in a popup or embedded interface.

#How It Works

This plugin uses Microsoft’s public online service (Office Web Viewer) to render previews. The basic workflow is as follows:

• The frontend generates a publicly accessible URL for the uploaded file (including signed URLs such as those from the S3-Pro plugin);

• The plugin embeds the preview in an iframe using the following format:

  https://view.officeapps.live.com/op/embed.aspx?src=<public file URL>

• Microsoft’s service fetches the file from the URL, renders it, and returns a previewable page.

#Notes

• Since this plugin depends on Microsoft’s online service, ensure that your network connection is stable and that Microsoft services are accessible.
• Microsoft will access the file URL you provide, and the file content may be temporarily cached on their servers for rendering. This introduces potential privacy concerns — if you're concerned about this, it's recommended not to use this plugin for sensitive documents¹.
• Files must be accessible via a public URL to be previewed. Normally, files uploaded to NocoBase will have public access links automatically generated (including signed URLs from the S3-Pro plugin). However, if access permissions are restricted or the file is stored in an internal network, it cannot be previewed².
• This service does not support authentication or private storage. For example, files that require login or are only accessible on an internal network will not work with the preview functionality.
• After Microsoft retrieves the file, it may remain cached for a short period. Even if the source file is deleted, the preview might still be accessible for some time.
• Recommended file size limits: Word and PowerPoint files should be no larger than 10 MB, and Excel files no larger than 5 MB for reliable preview performance³.
• There is no official public statement regarding commercial usage of this service. Please assess the risks before using it in commercial applications⁴.

#Supported File Types

This plugin only supports previews for the following Office file formats, based on the file's MIME type:

• Word Document:
  application/vnd.openxmlformats-officedocument.wordprocessingml.document
• Excel Spreadsheet:
  application/vnd.openxmlformats-officedocument.spreadsheetml.sheet
• PowerPoint Presentation:
  application/vnd.openxmlformats-officedocument.presentationml.presentation

Other file formats will not be previewed by this plugin.

#Footnotes

1. What is the status of view.officeapps.live.com? ↩

2. Microsoft Q&A - Access denied or non-public files cannot be previewed ↩

3. Microsoft Q&A - File size limits for Office Web Viewer ↩

4. Microsoft Q&A - Commercial use of Office Web Viewer ↩