Checking for 'undefined' variable in template

[byoungdale]

I have a simple template where I am trying to check for the presence of an error message:

% view.layout = 'default';
<h2><%= msg %></h2>
% if (err) {
    <p style="color:red"> <%= err %> </p>
% }
%= await ctx.include({view: 'signup/_form'}, {caption: 'Sign up with Email', target: ['create_signup']})

But, if err is undefined, mojo is throwing an error:

ReferenceError: /Users/byoungdale/JavascriptProjects/website/views/signup/show.html.tmpl:3
    1| % view.layout = 'default';
    2| <h2><%= msg %></h2>
 >> 3| % if (err) {
    4|     <p style="color:red"> <%= err %> </p>
    5| % }

err is not defined

Is there a different way I should be doing this?

[kraih]

You could set app.defaults.err = null; to have it always be something in templates. Or you can check if (ctx.stash.err).

[byoungdale]

ah, I see. Thank you!