[KevinH]

Do we need a new Tool menu item to "Use Standard File Extensions"?

This would be a tool which would walk all files in the epub, and based on their declared OPF manifest media-type check the file extension and if needed add or change the extension.

Basically it would be an reverse (with more alternate media-types added) of this kind of table:

void MediaTypes::SetExtToMTypeMap()
{
    if (!m_ExtToMType.isEmpty()) {
        return;
    }
    // default to using the preferred media-types ffrom the epub 3.2 spec
    // https://www.w3.org/publishing/epub3/epub-spec.html#sec-cmt-supported
    m_ExtToMType[ "bm"    ] = "image/bmp";
    m_ExtToMType[ "bmp"   ] = "image/bmp";
    m_ExtToMType[ "css"   ] = "text/css";
    m_ExtToMType[ "epub"  ] = "application/epub+zip";
    m_ExtToMType[ "gif"   ] = "image/gif";
    m_ExtToMType[ "htm"   ] = "application/xhtml+xml";
    m_ExtToMType[ "html"  ] = "application/xhtml+xml";
    m_ExtToMType[ "jpeg"  ] = "image/jpeg";
    m_ExtToMType[ "jpg"   ] = "image/jpeg";
    m_ExtToMType[ "js"    ] = "application/javascript";
    m_ExtToMType[ "m4a"   ] = "audio/mp4";
    m_ExtToMType[ "m4v"   ] = "video/mp4";
    m_ExtToMType[ "mp3"   ] = "audio/mpeg";
    m_ExtToMType[ "mp4"   ] = "video/mp4";
    m_ExtToMType[ "ncx"   ] = "application/x-dtbncx+xml";
    m_ExtToMType[ "oga"   ] = "audio/ogg";
    m_ExtToMType[ "ogg"   ] = "audio/ogg";
    m_ExtToMType[ "ogv"   ] = "video/ogg";
    m_ExtToMType[ "opf"   ] = "application/oebps-package+xml";
    m_ExtToMType[ "opus"  ] = "audio/opus";
    m_ExtToMType[ "otf"   ] = "font/otf";
    m_ExtToMType[ "pls"   ] = "application/pls+xml";
    m_ExtToMType[ "pdf"   ] = "application/pdf";
    m_ExtToMType[ "png"   ] = "image/png";
    m_ExtToMType[ "smil"  ] = "application/smil+xml";
    m_ExtToMType[ "svg"   ] = "image/svg+xml";
    m_ExtToMType[ "tif"   ] = "image/tiff";
    m_ExtToMType[ "tiff"  ] = "image/tiff";
    m_ExtToMType[ "ttc"   ] = "font/collection";
    m_ExtToMType[ "ttf"   ] = "font/ttf";
    m_ExtToMType[ "ttml"  ] = "application/ttml+xml";
    m_ExtToMType[ "txt"   ] = "text/plain";
    m_ExtToMType[ "vtt"   ] = "text/vtt";
    m_ExtToMType[ "webm"  ] = "video/webm";
    m_ExtToMType[ "webp"  ] = "image/webp";
    m_ExtToMType[ "woff"  ] = "font/woff";
    m_ExtToMType[ "woff2" ] = "font/woff2";
    m_ExtToMType[ "xhtml" ] = "application/xhtml+xml";
    m_ExtToMType[ "xml"   ] = "application/xml";
    m_ExtToMType[ "xpgt"  ] = "application/vnd.adobe-page-template+xml";
}

where instead of using the file extension to look up a media-type, you would use the media-type to look for the proper file extension and use that in a rename if needed.

This could be done easily and make sure all css files end with .css, all xhtml files end with .xhtml, all jpegs files end up with .jpg, etc.

Could be a nice first step when you first start editing a rough built epub.

Would this kind of tool be useful to anyone?

If so I could also add it as a possible Automate action as well.

Any thoughts?