# eXo Onlyoffice add-on

This add-on allow editing office documents directly in eXo Platform using ONLYOFFICE™ Documents Server. Thanks to the introduced menu items, in action bar of Documents explorer, users of eXo Platform can switch to editor in file preview of any supportable office document. As for now, the add-on offers support of following formats: 
- Office Open XML (Microsoft Office 2007 and later):
  - Word (.docx)
  - Excel (.xlsx) 
  - PowerPoint (.pptx) 
- Open Document Format (OpenOffice and LibreOffice):
  - Text (.odt)
  - Spreadsheet (.ods)
  - Presentation (.odp)
 
The Document Server should be [installed](http://helpcenter.onlyoffice.com/server/document.aspx) on reachable network. ONLYOFFICE™ offers native installers for Windows and Linux, they also have [Docker installation](http://helpcenter.onlyoffice.com/server/docker/document/docker-installation.aspx) which will be described below in details. 

A demo video where we edit Word document in eXo Platform using ONLYOFFICE editor:
[![Watch demo video](/docs/images/youtube_screen.png)](https://www.youtube.com/watch?v=Ifioa0GfG-k)

## Usage

Since add-on installed, it adds two menu items in Document explorer action bar: "Edit In Onlyoffice" and "Close Onlyoffice". These menu items available in file preview mode (need open a file in the explorer) and also work for large files when preview not possible. 

![Editor in Action bar](/docs/images/action_bar.png)

After user will choose to open an editor for current file, it will be loaded instead of file preview. As Onlyoffice requires some time to download the document content to its Document Server and then prepare an UI, users will need wait for seconds before starting to work. Large files may require more time for loading (e.g. spreadsheets with lot of cells). 

![Editor open](/docs/images/editor.png)

When users start to edit a document it's important to understand how Onlyoffice editor works. All modifications will go to a temporal storage in the Documents Server and only after all editors will be closed, in about 10 seconds, the file will be updated in eXo Platform. Thus, while document is open in the editor, all users opened it see actual state, but if look at the preview in eXo it will show a state before the editing session start.
To finish editing the document, user closes the editor by menu "Close Onlyoffice".

When several users edit the same document, it is required to make extra operations to get synced with others. In single user mode all editings will be applied immediately to the document temporal storage. But when multiple users open the document and someone edits it, the edited part of the document will be locked for others until this user save the document explicitly using _Save_ menu. After document saved current user will see also changes of others (in other paragraph, table cell etc). But others, in order to see remote modifications, will need also to click _Save_ button in their editors, even if they haven't changed anything. Onlyoffice shows a popover on the _Save_ button by default when document changed by others, it lets user to see need of such synchronization.

![Co-editing](/docs/images/coediting.png)

## Installation

### ONLYOFFICE™ Document Server

ONLYOFFICE™ Document Server can be [installed](http://helpcenter.onlyoffice.com/server/docker/document/docker-installation.aspx) in Docker container from ready image with pre-configured defaults. While this add-on has no constraints on how the Onlyoffice installed, Docker way is a simplest and strightforward way to add Document Office to you infra, for both development or production. Document Server is an Open Source Software, thus if you'll need to customize it, it's always possible to get the sources and make your Docker image.

When you have installed Docker, you need a single command to start the Document Server on-premise:

    sudo docker run -i -t -d -p 80:80 onlyoffice/documentserver

The Document Server needs only port 80 by default, but you also can run in on HTTPS. Follow its guides for more detailed setup.

To check you have running Document Server successfuly, open a page on its address [http://DOCUMENT\_SERVER\_HOST/OnlineEditorsExample/](http://localhost/OnlineEditorsExample/), it will show you simple demo page where you can upload a document, or use their sample, and try to edit online in your browser. After you'll see it works well, you are ready to install the add-on in eXo Platform.

### eXo Platform Add-on
After you successfuly installed ONLYOFFICE™ Document Server, you need install Onlyoffice add-on to eXo Platform server. It should be Platform version 4.3 or higher. 

If you want use released binaries from eXo Catalog, simple run command in root of the server:

    > ./addon install exo-onlyoffice

When building from sources, then go to `/packaging/target` folder of the project and extract `exo-onlyoffice-packaging.zip` to a root of your server. You also may setup local add-ons catalog for eXo Addon manager if plan development with frequent installations, and then use this archive as a local package.

## Configuration

Onlyoffice add-on need to know an adress of your Document Server and eXo Platform server, and it's also required to point a protocol scheme to use (`http` or `https`). Add following lines to your `exo.properties`.

For Platform 4.4 and higher:

    onlyoffice.documentserver.host=YOUR_DOCUMENT_SERVER_HOST
    onlyoffice.documentserver.schema=http
    onlyoffice.documentserver.secret=SECRET_KEY

For Platform 4.3 also need point your server public host and schema:

    onlyoffice.server.host=YOUR_EXO_SERVER_HOST
    onlyoffice.server.schema=http

Where `YOUR_DOCUMENT_SERVER_HOST` is an IP or host name of Document Server and `YOUR_EXO_SERVER_HOST` host ip or name (with port if not 80 or 443) of your eXo Platform server.

## Security

ONLYOFFICE™ Document Server standalone doesn't offer a user authorization or such integration with external identities. As a result it's required to place it in secure network and for production it will be mandatory to run via [HTTPS](http://helpcenter.onlyoffice.com/server/docker/document/docker-installation.aspx#RunningHTTPS) or even use [strong SSL security](https://raymii.org/s/tutorials/Strong_SSL_Security_On_nginx.html). 

As it's not possible to provide user authorization between eXo and Onlyoffice servers, but need allow the Document Server access documents in eXo Platform, this addon implements document flow based on single session random idetifier for a file. Each new editor session uses a new ID for the same file. It doesn't let to guess a concrete file ID to download its content, but if someone will get current session ID it would be possible to grab the content. 

To minimize security flaws, in addition to HTTPS, the add-on restricts an access to document content and state RESTful services by allowing requesting them only by configired document server host. The Document Server host set in `exo.properties` as `onlyoffice.documentserver.host` will be used to check client requests. Requests from other hosts will be rejected with 401 response. 

Indeed, in some cases, it may be required to allow requests from any client host (e.g. for development or in case of proxy/NAT settings), then you can disable such restriction by setting following property to `false` value:

    onlyoffice.documentserver.accessOnly=false

Allowing access from any host, if no other security protection implemented, **strongly not recommended** as mentioned RESTful end-points can be accessed by anyone (doesn't check eXo credentials to allow the Document Server work with them). 

The Document Server uses tokens generated using the JSON Web Tokens standard to secure access. For the validation setup it is necessary to edit the configuration file which can be found (or created) at the following path:

For Linux - /etc/onlyoffice/documentserver/local.json.
For Windows - %ProgramFiles%\ONLYOFFICE\DocumentServer\config\local.json.

You need to enable tokens validation and set up the secret key.
To enable tokens validation set true values to the params:

    services.CoAuthoring.token.enable.request.outbox
    services.CoAuthoring.token.enable.request.inbox
    services.CoAuthoring.token.enable.browser
    
Specify the secret key in

    services.CoAuthoring.secret.outbox.string
    services.CoAuthoring.secret.inbox.string

Save the local.json and restart the services: 

    supervisorctl restart all

For more detailed information check the [Onlyoffice API Documentation](https://api.onlyoffice.com/editors/signature/)

### Events

Onlyoffice add-on publishes some eXo listener events to let end-user apps listen on them and build required data/output for collecting stats or other purposes.

The add-on broadcasts such events (the constants are available in OnlyofficeEditorService interface):

    EDITOR_OPENED_EVENT - exo.onlyoffice.editor.opened
    EDITOR_CLOSED_EVENT - exo.onlyoffice.editor.closed
    EDITOR_SAVED_EVENT - exo.onlyoffice.editor.saved
    EDITOR_VERSION_EVENT - exo.onlyoffice.editor.version
    EDITOR_ERROR_EVENT - exo.onlyoffice.editor.error

The opened and closed events are published when an user opens or closes the editor relatively. The saved event appears when the last user has closed a document and its content has been saved.
The version event is published when a new version of a document has been created due to coediting or autosave time.
The error event appears when an error has occured while working with the Document Server.

The data object passed to the event has DocumentStatus class which contains some useful information for end-user apps. For example, it contains the config, that has a full information about the editor, including the opened and closed times (for the opened and closed events). The coEdited field helps to figure out the original reason of the version event (true means that the version has been created becouse of coediting, false - due to autosave timer)
