How to implement search and filtering in a REST API using nodejs and express

Question

I learn and play with Node and Express, creating a REST API. I do not have a database for storing data, I do everything in memory.

Let's say I have an array of users:

var users = [{"id": "1", "firstName": "John", "lastName": "Doe"}];

and defined the getAllUser function:

exports.getAllUser = function(page, items) {
  page = (page < 1 ? 1 : page) || 1;
  items = (items < 1 ? 5 : items) || 5;
  var indexStart, indexEnd;
  indexStart = (page - 1) * items;
  indexEnd = indexStart + items;
  return users.slice(indexStart, indexEnd);
};

and defined the route:

router.get('/users', function(req, res, next) {
  var page = req.query.page;
      items = req.query.items;
  page = page !== 'undefined' ? parseInt(page, 10) : undefined;
  items = items !== 'undefined' ? parseInt(items, 10) : undefined;

  res.status(200).json({ users: users.search(page, items) });
});

This all works great, I was able to test it using Postman, and my data is being returned.

My question is: how to implement search and filtering?

From what I understand, search parameters will be passed to the URL as parameters, for example:

http://localhost:8080/api/users/firstName=john&age=30

How can I extract these parameters using node, and is there a specific library to use or best practices?

The same question for filtering or filtering the same as the search?

Answer 1

req.query.

{ 'firstName': 'john', 'age': '30' }

arr.filter(callback[, thisArg]) .

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/filter

- :

function search(query) {
  return function(element) {
    for(var i in query) {
      if(query[i] != element[i]) {
        return false;
      }
    }
    return true;
  }
}

exports.search = function(query) {
  return users.filter(search(query));
}

:

router.get('/users', function(req, res, next) {
  return res.json({ users: users.search(req.query) });
});

. search - , ..