OnlyOffice connector should allow to create and edit OpenDocument formats without conversion

[ldubost]

Currently it does a conversion, but it could do the full conversion on the fly when editing/saving

[trrenty]

The Open Document Format (ODF) files can now be edited inside XWiki. First, the Admin has to change the "Conversion" field in the Administration Section of the OnlyOffice App.

The Admin can choose between three methods of editing an ODF file (I will now use ODT to refer to ODF and DOCX to refer to OOXML):

• Convert to a different file - the default (old) behaviour. When editing an ODT file, the user needs to convert it to DOCX and then edit the newly created file.
• On the fly using OnlyOffice - the user can open and edit the ODT file but, because of the inner workings of OnlyOffice, the file will be converted to DOCX on the fly and, when saving the file, convert it back to ODT
• On the fly using Office Server - the user can open and edit the ODT file but before opening it in OnlyOffice it will be converted to DOCX using the configured Office server. When saving the file, it will be converted back to ODT using the same method. Note that the wiki instance should be connected to an Office Server and the have a configuration that allows conversion betweeen DOCX and ODT. The default configuration of XWiki doesnt support ODT to DOCX conversion. See https://forum.xwiki.org/t/office-conversion-configuration-document-formats-js-is-not-up-to-date/10786.

If the user selects the third method and the Office Server is not connected, a warning will be displayed:

Some UI changes had to be made:

• Creating a new file will prompt the user to select from the available formats
  

• Similarly, when opening a file that needs conversion, It will prompt the user to select the format in which to convert.
  

• When editing a file that needs conversion but versions of it that are in editable formats exist, the user will need to select the desired version to edit.
  

[lucaa]

A fix was added in platform version 14.4.3 which may have an impact on the docx to odt conversion https://jira.xwiki.org/browse/XWIKI-19818 . Please make sure to test on XWIKI 14.4.3+ or 14.6+

[trrenty]

Tested on Kubuntu 22.04 XWiki 14.4.3 Jetty HSQLDB.

• Uploaded an ODT file.
• Select "Convert using Office Server" in admin section.
• Edit ODT file.
• The file was successfully converted to DOCX using the OfficeServer and uploaded to OnlyOffice server.
• Modified the file and saved.
• The file was successfully downloaded from the OnlyOffice server as DOCX, converted to ODT using OfficeServer and saved to the XWiki page.

Downloading and opening the file in LibreOffice displays a normal ODT file.