TH: assert usage in thymeleaf

TH: assert asserted tag

TH: The assert attribute can be used to specify a comma-separated expression to evaluate the expression and produce a value suitable for each evaluation. If no exception is thrown

<Div TH: assert = "$ {onevar}, ($ {twovar }! = 43) ">... </div>

This facilitates the signature of a part of the parameter.

<Header TH: fragment = "contentheader (title)" TH: assert = "$ {! # Strings. isempty (title)} ">...  
In this way, only the input value can be introduced successfully, otherwise it will not be introduced.
 
TH: assert usage in thymeleaf