Jade conditional (if/else) to add class to div inline

Question

Is there a way to do this inline in a jade template?

if(typeof fromEdit != 'undefined')    div#demo.collapse.in else    div#demo.collapse 

Would like to do this conditional check "inline" and the result would add the .in to the end of the div if fromEdit exists.

Answer 1

This works:

div#demo.collapse(class=typeof fromEdit === "undefined" ? "" : "in") 

Try it out here.

Answer 2

If you don't want the class attribute to be added when there is no value, you can assign it undefined instead of an empty string. Here is the previous example, slightly modified:

div#demo.collapse(class=typeof fromEdit === "undefined" ? undefined : "in") 

Update: Also, if you are using pug, you can now add as many class= declarations as you want with different conditions and they'll get concatenated in the resulting class attribute. e.g.:

#demo.collapse(class=cond1 && 'class1' class=cond2 && 'class2')