Rendering elements classname in client-side without JS framework? (EJS) - node.js

Question

Let's say I have an app which shows to the users a list of existing hobbies.
Each hobby has a category, stored in the db.
I want every hobby element to have its background color - dependent on its category.
I want to implement this with appending specific class to each element.
Basic example code:
Server
app.get("/hobbies", (req, res) => {
const hobbies = Hobby.getAllHobbies();
res.render("hobbies", hobbies);
});
Client (EJS)
<% hobbies.forEach(hobby => { %>
<div class=""><%= hobby.name %></div>
<% }); %>
What is the best way to append to each div a class depending of hobby.category?
I know its easily possible in React, but I don't want to use any framework for now.

Answer 1

If your classname is not the same as the category but is based on it, then you just need to pass a lookup object to your template.
Server
const categories_classnames = {
lookup: {
swimming: 'div-swim',
biking: 'div-bike',
painting: 'div-paint',
// ...
}
};
app.get("/hobbies", (req, res) => {
const hobbies = Hobby.getAllHobbies();
// Alternatively, `locals = { ...hobbies, ...categories_classnames }`
const locals = Object.assign({}, hobbies, categories_classnames);
res.render("hobbies", locals);
});
Client
<% hobbies.forEach(hobby => { %>
<div class="<%= lookup[hobby.category] %>"><%= hobby.name %></div>
<% }); %>