express-pagination-middleware

This module exports a function that takes a configuration object parameter with the following properties:

{
    sort: {
        validKeys: Array of strings (case sensitive),
        default: String (optional, by default assigned to the first element of the
                    validKeys array with ascending sorting order unless prefixed by a "-")
    },
    limit: {
        min: number (optional, default: 5),
        max: number (optional, default: 100),
        default: number (optional, defaults to min)
    }
}

and returns an express compatible middleware function (req, res, next) that parses the following parameters from the req.query object and sets an object on the req.pagination having the following properties:

{
    sort: Object - with keys for the sort value fields and value a boolean denoting ascending order
                   or not
    limit: number - the limit of records to return (if not specified a default value from the
                    configuration object is used)
    skip: number - the number of records to return (if not specified this property has a 0 value)
}

Use it

To use this module first install it in your project using npm

npm install --save express-pagination-middleware

then in your express application

...
var paginationMiddleware = require("express-pagination-middleware");
var userPaginationMiddleware = paginationMiddleware({
    sort: {
        validKeys: ["created", "age", "email"]
    },
    limit: {
        min: 10,
        max: 500
    }
});

// matching the url http://.../users?sort=created&limit=20&skip=40
router.get("/users", usersPaginationMiddleware, function (req, res, next) {
    // now the req parameter will have pagination property with all the required info
    // req.pagination = {
    //     sort: {
    //         created: true
    //     },
    //     limit: 20,
    //     skip: 40
    // }
    Users
      .find()
      .sort(req.pagination.sort)
      .skip(req.pagination.skip)
      .limit(req.pagination.limit)
      .exec()
      .then(res.json.bind(res))
      .catch(next);
}

Contributing

Feel free to contribute to this project but please open pull requests only on the development branch and make sure you include tests for new functionality or issues identified with the codebase.

All PR's should pass the test build to be considered for merging.