To allow users to select a specific category to search in, we will set up an API that retrieves all the distinct categories present in the Product collection in the database. A GET request to /api/products/categories will return an array of unique categories.
mern-marketplace/server/routes/product.routes.js:
router.route('/api/products/categories') .get(productCtrl.listCategories)
The listCategories controller method queries the Product collection with a distinct call against the category field.
mern-marketplace/server/controllers/product.controller.js:
const listCategories = (req, res) => { Product.distinct('category',{},(err, products) => { if (err) { return res.status(400).json({ error: errorHandler.getErrorMessage(err) ...
