Nextcloud Office (Collabora)

Collabora Online provides real-time, high-fidelity document editing within Nextcloud. It features WYSIWYG rendering that preserves document layout and formatting.

Key capabilities include:

• Real-time Collaboration: Multiple users can edit documents simultaneously.
• Commenting: Users can insert and reply to comments.
• Anonymous Editing: Users without a Nextcloud account can edit files via public link shared folders.
• Broad Format Support: Supports DOC, DOCX, PPT, PPTX, XLS, XLSX, ODF, Visio, Publisher, and more.

For developers and home users, Collabora Online Development Edition (CODE) is available via a Docker image. Enterprise users requiring higher stability and scalability should use the Collabora Online Enterprise version.

When using the "Generate Office text document" task type in the Assistant, the system follows a multi-step conversion pipeline to create .docx, .odt, or .pdf files from a user prompt:

1. Markdown Generation: The prompt is used to generate Markdown content via a TextToText provider.
2. HTML Conversion: The generated Markdown is converted into HTML.
3. Collabora Conversion: The HTML is sent to Collabora Online, which converts it into the final document format.

To allow the Collabora editor to communicate with a mobile client (e.g., a native app), the client must register a JavaScript handler named RichDocumentsMobileInterface in the webview. The editor expects the following methods to be implemented by the client:

• close(): Closes the webview.
• share(): Opens the share sidebar or dialog for the current file.
• documentLoaded(): Called once Collabora has loaded; the client can use this to hide the loading screen.
• paste(): Triggered to allow integrating applications to pass clipboard content to the editor.
• fileRename(): Notifies the client that the current file has been renamed.
• downloadAs(): Hands over a download link to the client application.

You can control access to the Nextcloud Office (Collabora) app using group restrictions:

• Restrict usage: When active, only members of specified groups can use Nextcloud Office.
• Restrict edit: When active, only members of specified groups can edit documents; all other users are restricted to view-only mode.

Collabora Online emits post messages to the WOPI host (Nextcloud). These messages are caught by the Nextcloud Office integration and re-emitted through the Nextcloud event bus. You can listen to these messages using the following event name:

• richdocuments:wopi-post

For a complete list of available messages, refer to the Collabora Online PostMessage API documentation.

When using the "Generate Office spreadsheet document" task type in the Assistant, the system follows this pipeline to create .xlsx or .ods files from a user prompt:

1. CSV Generation: The prompt is used to generate CSV content via a TextToText provider.
2. Collabora Conversion: The CSV content is sent to Collabora Online, which converts it into the final spreadsheet format.

By default, Collabora Online restricts embedding to the same remote that loaded the initial frame. To allow embedding from trusted remotes (such as different Global Scale nodes), you must update the Content Security Policy (CSP) using the coolconfig tool. This allows the document to be framed by the specified domains.

coolconfig set net.content_security_policy "frame-ancestors *.example.com:*;"

To enable collaborative editing of federated documents, ensure the following requirements are met:

1. Version Requirement: All involved servers must be running richdocuments version 3.4 or higher.
2. Trusted Servers: The remote server must be added as a trusted server in the Nextcloud configuration.
3. Frame Embedding: You must allow any domain to embed Collabora Online in a frame by setting the following in your coolwsd.xml configuration: <frame_ancestors>https://*</frame_ancestors>

Note: Due to content security policies, opening a document on a remote instance requires a page reload to allow Nextcloud to embed the remote Collabora Online instance in a frame.

By default, the trusted hosts defined in Nextcloud's core configuration are not permitted for federated editing. To allow federated editing to use these trusted domains, you must enable the federation_use_trusted_domains setting in the richdocuments app configuration via the occ command.

occ config:app:set richdocuments federation_use_trusted_domains --value="yes"