如何在 ejs 视图中作为 ejs 变量访问 js 变量（在脚本标签内）

Question

I have a script in order to get the selected option of a select tag in my ejs view, this is in order to dynamically set the value of the name attribute to the selected option. I then use the name of this input tag in my nodeJS server-side. However, I receive ReferenceError: p is not defined .

What is the correct way to access the JS variable in my ejs view?

EJS

<select>
    <option>A</option>
    <option>B</option>
    <option>C</option>
</select>

<!-- JS as a tag in the EJS !-->
<script>
let p = document.querySelector('select').selectedOptions[0].value;
</script>

<input type="file" name="<%= p %>">

Any help much appreciated. Thank you.

Answer 1

EJS code is executed on the the server and JS code is executed on the browser.

The only way to have EJS access your DOM variable is if there was a call to the backend API via JS code and then have that evaluated and returned to frontend, but this is a poor design and is not recommended.

Its better you handle the the value of tag via JS only, the details will be sent to sever on form submission.