I had to configure a new template in order to monitor some http redirections, they should change every 24h or an alarm has to raise.
I did not find how do do this trough the web gui, I could't create a trigger to comparte the actual item text value to the one 24h ago (didn't find an easy way to compare strings), but was able to do it via UserParameters:
So basically I get the URL of the redirection with curl, hash it with md5, that gives a hex number, which is converted to decimal.
That number is too big to be stored on a item as a float, so it is divided by 1e27.
I thought that a preprocessing option to convert any text to a numeric hash value (probably using a more suitable hash function) can come very handy, as a easy way to compare strings in order to create triggers.