我试图从后端显示错误但错误发生 EJS

Question

When I tried to display an error message from the backend using EJS I'm getting some errors? Can someone help me fix this???

Here is a snippet from my home.ejs file:-

          <% if (err) { %>
          <!-- contact-warning -->
            <div id="message-warning">
              <p><%= err.msg %></p>
            </div>
          <% } %>

          <% if (success) { %>
          <!-- contact-success -->
            <div id="message-success">
              <i class="fa fa-check"></i> <br />
              <p><%= success.msg %></p>
            </div>
          <% } %>

and here is my node code snippet

if (error) {
      console.log(error);
      let err = {
        msg: "Email Sent failed",
      };
      res.render("home", { err });
    } else {
      let success = {
        msg: "Your message was sent, thank you!",
      };
      res.render("home", { success });
    }

and I'm getting this error err is not defined

Answer 1

For the if/else branch, you still need to pass the variables used in the ejs view.

if (error) {
  console.log(error);
  let err = {
    msg: 'Email Sent failed',
  };
  res.render('home', { err, success: null });
} else {
  let success = {
    msg: 'Your message was sent, thank you!',
  };
  res.render('home', { success, err: null });
}

Answer 2

You also could use typeof in if without passing other variables to your ejs .

<% if (typeof err !== "undefined") { %>
    <div id="message-warning">
    <p><%= err.msg %></p>
    </div>
<% } %>

<% if (typeof success !== "undefined") { %>
    <div id="message-success">
    <i class="fa fa-check"></i> <br />
    <p><%= success.msg %></p>
    </div>
<% } %>

You could use original logic without passing null.

if (error) {
    console.log(error);
    let err = {
        msg: "Email Sent failed",
    };
    res.render("home", {
        err
    });
} else {
    let success = {
        msg: "Your message was sent, thank you!",
    };
    res.render("home", {
        success
    });
}