Some files may not get updated
|Kroy Ellis||06/28/2006 03:03 pm|
|If in the project dialog, "Download only new and modified files" AND "Check file size" are checked, what will happen if:
A file on the server has changed (different date or time), but SIZE IS THE SAME. E.G. Price in database has been changed from $235 to $290 (a frequent occurrence), but no change in no. of bytes.
OE will not download the file even tho it has changed, correct? If not, you need an option to download the file if ANYTHING HAS CHANGED, INCLUDING file size.
The HELP info indicates that updated files with the same size will NOT be downloaded if "Check file size" is checked, even if the file has changed, which would be the case with cgi-bin, ASP and database access scripts according to the help info.
People may think they've got the latest files downloaded, but if prices or something else changes daily on the page, the page(s) may never get updated and the user would never know.
|Oleg Chernavin||06/28/2006 03:10 pm|
|Yes, there is an issue of this kind. This is why we made Check Size optional. You may also check by CRC, but this requires the file to be downloaded in any case and then checked against the file on the disk. This is a much more rare case when it could be helpful.
|Kroy Ellis||06/28/2006 03:26 pm|
|You need an option to download the file if EITHER DATE, TIME *OR* FILE SIZE has changed, if I understand the way this works now.
btw, thanks for the BEST, fastest tech support I've seen from ANY company I've ever dealt with!
|Oleg Chernavin||06/29/2006 03:03 am|
|It works exactly this way. If the server supplies the file modification date, Offline Explorer uses it and ignores the file size. If no file modification date is in the file response header, it uses file size.
|Kroy Ellis||06/29/2006 10:48 pm|
|"If the file size has not changed since the previous download, OE considers the file to be the same. In rare cases [not necessarily] the updated file may have the same size. So please use this feature with caution."
I may be misunderstanding the help info. It sounds like the date or time of a file could change, but if "Check file size" is checked, A FILE HAS BEEN UPDATED, BUT THE SIZE HAS NOT CHANGED (not uncommon such as with frequent price changes on a page), "OE considers the file to be the same," and therefore DOES NOT DOWNLOAD IT.
But if I understand your explanation correctly, the updated file WILL still be downloaded (date or time have changed), even if the size hasn't changed and "Check file size" is checked.
I know I may seem to be belaboring the point, but its important in my case, since I use OE for downloading price list sites I sell products for. I have to KNOW that every page is current daily when doing a download, but prefer not to regularly download the entire site.
I could always test it, and see the results, but haven't had time yet.
|Oleg Chernavin||06/30/2006 08:12 am|
|Many servers do not supply file modification date and if it is missing, check size may give you improper results if the size is really the same. To help you better, can you tell me a couple of links to the files that you need to check. I will see how they work.
|Kroy Ellis||06/30/2006 05:13 pm|
|Ok Oleg, will do if/when I come across any.
I just wanted to get the best understanding of how it worked for downloading the sites I use that are updated often with price changes, but file sizes often don't change (eg. www.benchdepot.com).
I'll keep an eye on what gets downloaded with it checked and unchecked and see how it goes.