Hi, my application receives some dates in textual formats from the Internet; some of them are in RFC2822's format "Mon, 11 Jun 2012 13:35:56 -0700" (and other variants due to backward compatibility), others in RFC3501's "date-time" format which is "07-Mar-2007 15:03:32 +0100".
I'd like to save them into a QDataStream for further retrieval and after loading them back, I'd love to show them both converted to the user's local time and also in the original format, including the original time zone information. I haven't found a way of doing this in Qt and would like to ask for help about that. Right now my code makes the parsing by hand ([1] for the RFC2822 dates and [2] for the IMAP's format) because I have to work with the timezone from information the string and QDateTime's public functions don't seem to offer a way of doing that when working with custom date formats which I need. After the timestamp is parsed, I add/subtract the correct number of seconds from the resulting QDateTime and afterwards I tell Qt that my resulting QDateTime is in the UTC format. After that, I can easily show it converted to the user's local time. What I'm missing are two bits: - A public API for telling Qt "hey, set the date to exactly this value and remember the timezone, which is *this*". I could probably hack around this one by constructing a string from the already parsed QDateTime, adding my TZ information to the end of that and calling QDateTime::fromString(Qt::ISODate), but that looks like a crude hack. Essentially the Qt::ISODate format specifier looks like the only publicly available function which accepts timezone specification. - A formatting specifier used for producing the TZ information in a text form. My code is an e-mail reader and I don't rely on locale's way of showing data (I want to show just "10:30" for today's mails, for example, see [3]). It seems that there's no publicly available format-string specifier which could produce the TZ info. Again, I can probably hack around that by doing stuff similar to how I produce "current time" in RFC2822 [4] and manual operations on the formatting string (ie. introduce a special application-specific modifier "Z" for timezone information, check the format string for its occurrence, split the formatting specifier into two parts, before the specifier and after that, call QDateTime's toString() on them and add the determined TZ info back manually, but that looks like an awful amount of work. So, the questions: - Is there a publicly available way of doing what I want to do, ie. am I missing something? - Does Qt5 change anything in this matter? - Shall I bother with this fancy formatting using an approach I've outlined above, including that string -> QDateTime -> string -> QDateTime conversion? - Would I hit any obstacle in Qt 4.7+ if I decied to use QDateTime's *internal* functions setUtcOffset() and utcOffset()? I see that I shouldn't be using them, but in this case it seems to me that they publish information which is only hardly available in other ways, so it's *so* tempting to just have a look at them. I'm looking forward to your opinion. With kind regards, Jan [1] https://projects.flaska.net/projects/trojita/repository/revisions/d365ab2/entry/src/Imap/Parser/LowLevelParser.cpp#L319 [2] https://projects.flaska.net/projects/trojita/repository/revisions/d365ab2/entry/src/Imap/Parser/Response.cpp#L696 [3] https://projects.flaska.net/projects/trojita/repository/revisions/d365ab2/entry/src/Imap/Model/PrettyMsgListModel.cpp#L174 [4] https://projects.flaska.net/projects/trojita/repository/revisions/d365ab2/entry/src/Imap/Model/Utils.cpp#L474 -- Trojita, a fast e-mail client -- http://trojita.flaska.net/
signature.asc
Description: OpenPGP digital signature
_______________________________________________ Interest mailing list Interest@qt-project.org http://lists.qt-project.org/mailman/listinfo/interest
