How do I connect a variable to a string in Smarty?

Functiona is a custom smarty plug-in that has a parameter URL.
However, the value of the URL consists of the string 1, the variable $onetopic.id, and the string 2.

{Fuctiona url= ' str2{$onetopic. Id}str2 '}

{Fuctiona url= ' str2 '. ' $onetopic. Id '. ' Str2 '}

I tried the above several forms can not! Daniel, teach me a little bit!

Reply to discussion (solution)

{Fuctiona url= "str2{$onetopic. Id}str2"}

Not even.

Change it, divide it into multiple parameters, and change it in the function.

{Fuctiona url= "str2" |cat: $onetopic. Id|cat: "STR2"}

Cat is Smarty string connection function, you try more, long time no smarty

Thanks 4 5 Floor

Baidu found the answer, thanks to LZ share, here to make a mark,
More complex applications:

