Using Criteria in add-on

[Dadparvar]

Hi,

Can anyone post a complete tutorial on how to Criteria in add-on? (user, date, page ... criteria, which each has own tab normally in add-on page)

And also how to use them in act? Because it seems adding them to items in acp would be easy as adding some lines of codes. because xenforo did everything before and made it ready to use. But how to check them in result?

Thanks