Date written: February 4, 2015
This explains a way to get notified if this site changes, so you don't have to keep checking.
This site is largely static, with one exception. As an aid to anyone who might be interested in it, I wanted to make it easy to keep on top of potentially irregular or infrequent updates. To do that, I put on the main page a list of the top ten (or so) most recent updates. Then, every time I add an update, I regenerate the main page with the use of a REBOL script, and upload that main page to the site, thereby changing the date of the main page on the site.
The above procedure provides a way to keep track of updates. An automated procedure could check the main page, and if its modification date is different than it was the last time one checked, one would know that there would be something new to view.
Now, as to how to go about checking the date of the main page, one could practice one's REBOL by using it for that purpose. For example, try the following at the REBOL console:
print modified? http://www.cobolrebol.com/index.htmlREBOL can check the date of a file over the internet. So, we could take advantage of that with a modification of the following:
REBOL [ Title: "Site checker" ] TODAYS-DATE: now/date MODIFY-DATE-WHOLE: modified? http://www.cobolrebol.com/index.html MODIFY-DATE: MODIFY-DATE-WHOLE/date either equal? MODIFY-DATE TODAYS-DATE [ print "Modified today" ] [ print "NOT modified today" ] halt
If one ran the above script just before midnight, and replaced the "print" statements with maybe the "send" statement, one could email oneself a notification that the page had changed. Note that you couldn't do this in the middle of the day, because the page could change just after you ran the script and you would miss it, and then you would miss it the next day also.
Alternatively, you could save the modification date in a file, and then check the current modification date at any time and compare it to the saved date, and take appropriate action.
Anyway, those are just some ideas you could use to practice some simple REBOL tricks. You could expand that idea to other web sites.