I'm new to Node and Express. I am currently adding a pagination function to my API. Most of the hard work is done so far, but I can't make it work since I've refactored and made the pagination a function.
Here is my route:
const projects = require('../controllers/project.controller');
module.exports = (app) => {
var router = require('express').Router();
// Retrieve all project
router.get('/', projects.findAll);
};
Here is the middleware:
const paginatedResults = (model) => {
return (req, res, next) => {
const page = parseInt(req.query.page);
const limit = parseInt(req.query.limit);
const startIndex = (page - 1) * limit;
const endIndex = page * limit;
const results = {};
if (endIndex < model.length) {
results.next = {
page: page + 1,
limit: limit,
};
}
if (startIndex > 0) {
results.previous = {
page: page - 1,
limit: limit,
};
}
results.results = model.slice(startIndex, endIndex);
res.paginatedResults = results;
next();
};
};
const pagination = {
paginatedResults,
};
module.exports = pagination;
Here is my controller:
exports.findAll = (req, res) => {
Project.find({}, (err, data) => {
res.send(data);
});
};
I'm just wondering is there something I should change within the function? Ideally I'd like to be able to use in the route (e.g. router.get('/', [pagination.paginatedResults(Projects), projects.findAll]))
middlewares work one by one. You try to paginate when you have no results to paginate. If you are fine with using helper function, Try something like this.
//route
const projects = require('../controllers/project.controller');
module.exports = (app) => {
var router = require('express').Router();
// Retrieve all project
router.get('/', projects.findAll);
};
// controller
exports.findAll = (req, res) => {
const mongoQuery = Project.find();
const result = await paginateQuery(mongoQuery, req.query.page, req.query.limit);
res.send(result)
};
// helper
const paginateQuery =async (mongoQuery, page, limit) => {
const skip = page-1
const results =await mongoQuery.skip(skip).limit(limt)
// transform results the way you want and/or build response object
return results
};