Is there a way to show a pre-set username value to prevent receiving an error message that says it's undefined?

Question

Is there a way to show a pre-set username value to prevent receiving an error message that says it's undefined?

My navigation bar is set up to show the following on the right side of the screen:

Welcome, <%= user %>

The issue is that I can only access the user data if I render it in the following way:

router.get("/", function (req, res, next) {
  const user = req.user.username;
  res.render("index", user);
});

The problem arises when I'm not logged in, preventing the webpage from loading and showing an undefined error:

TypeError: Cannot read properties of undefined (reading 'username')

. Is there a solution to adding a default value for user or displaying a Sign Up button instead to prevent this TypeError?

javascript mongodb express ejs

Answer 1

Answer №1

Utilize the Nullish coalescing assignment (??=)

Instead of:

const user = req.user.username;

Use:

const user = req.user.username ?? 'default username';

documentation

Answer 2

Utilize the Nullish coalescing assignment (??=)

Instead of:

const user = req.user.username;

Use:

const user = req.user.username ?? 'default username';

documentation

Answer 3

Answer №2

I finally figured out a solution to this issue. Initially, I believed the only way to retrieve the user value was by rendering it in my index.js file. However, utilizing user.username in my ejs file allowed me to access the same value both when logged in and not logged in, resulting in successful page loading.

<% if (isAuthenticated) { %>
          <li class="dropdown">
            <a class="nav-link">
              <%= user.username %>
            </a>
          </li>
       <% } %>

Answer 4

I finally figured out a solution to this issue. Initially, I believed the only way to retrieve the user value was by rendering it in my index.js file. However, utilizing user.username in my ejs file allowed me to access the same value both when logged in and not logged in, resulting in successful page loading.

<% if (isAuthenticated) { %>
          <li class="dropdown">
            <a class="nav-link">
              <%= user.username %>
            </a>
          </li>
       <% } %>

Is there a way to show a pre-set username value to prevent receiving an error message that says it's undefined?

Answer №1

Answer №2

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