Yes, it can be used for math. You need to use the math format function. You can enable format functions under the Parameters tab. Details on how to use format functions can also be found under the Parameters tab. You'd likely need to do this anytime profile is updated and after registrations. So the following for example should work.
Global
Triggers: onAfterUserRegistration, onAfterNewUser, onAfterUpdateUser, onAfterUserUpdate
Type: Field
User: Automatic
Access: Everybody
Action
Field: cb_area
Operator: Set
Value:
[cb:parse function="math"][cb_width] * [cb_length][/cb:parse]
Parameters
Format Functions: Yes
You don't need CB Auto Actions for that though. You should be able to just use a Code field provided by CB Code Field and do your math entirely with some PHP. Example as follows.
Code:
return (int) '[cb_width]' * (int) '[cb_length]';
As long as you don't need the value stored in the database directly this should be sufficient for your needs, but if you need the value stored (e.g. searching purposes) you'll need to use CB Auto Actions.
krileon
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