Andromeda57 wrote: Do not find an answer there...
What do we have to write for the following case...
If field A is empty (not filled by user) -> Write the username of the user.
If it is not empty (user filled with a value) -> Write the value
......
I do not understand why you say that Kyle's link did not help you with your task.
Did you read it?
Specifically the last section?
From the tutorial:
---
Ifs
[cb:if PARAMETER="REPLACEMENT"]TEXT/CODE[/cb:if]
[cb:if username="demo"]This is Demo being displayed.[/cb:if]
[cb:if user_id="myid"]This is Me being displayed.[/cb:if]
[cb:if user="#displayed" username="test"]This is Test being displayed.[/cb:if]
[cb:if user="#me" username="demo"]This is Demo watching.[/cb:if]
[cb:if user="#me" usertype="Super Administrator"]User of type: Super Administrator[/cb:if]
[cb:if user="#displayedOrMe" user_id<="0"]I am A GUEST.[/cb:if]
[cb:if user="#displayedOrMe" user_id>"0"]I am NOT A GUEST.[/cb:if]
[cb:if user="#me" username!="admin"]This is NOT Admin watching.[/cb:if]
[cb:if viewaccesslevel includes "1"]I am Public[/cb:if]
[cb:if viewaccesslevel !includes "1"]I am NOT Public[/cb:if]
[cb:if gids includes "2"]I have Registered Usergroup[/cb:if]
[cb:if gids !includes "2"]I do NOT have Registered Usergroup[/cb:if]
[cb:if username="demo" or username="admin"]This is Demo or Admin being displayed.[/cb:if]
[cb:if username="demo" and cb_country="USA"]This is Demo being displayed from the USA.[/cb:if]
---
This basically gives you the method.
If your field is cb_myfield, then you could use:
[cb:if cb_myfield=""]just the [username][/cb:if]
[cb:if cb_myfield!=""]Just the [cb_myfield][/cb:if]