Backward compatibility expressions

Since the AppSheet platform is constantly being improved and updated, we've made some changes since we first got started: some expression components used to look a little different. We support the syntax below to accommodate apps that still use them.

• @(_HERE) returns the current location as a LatLong value; equivalent to HERE().
• @(_NOW) returns the current date and time as a DateTime value; equivalent to NOW().
• @(_TIMENOW) returns the current time as a Time value; equivalent to TIMENOW().
• @(_TODAY) returns the current date as a Date value; equivalent to TODAY().
• @(_UNIQUE) returns a new unique Text value suitable for use as a key; equivalent to UNIQUEID().
• @(_USEREMAIL) returns the user's email address as an Email value; equivalent to USEREMAIL().
• @(_USERNAME) returns the user's name as a Name value; equivalent to USERNAME(). Note that the user's name may not be reliably available to AppSheet, so this value should not be considered a reliable identifier.