sails-count-middleware

While paginating, find the total count by criteria, via an added X-Total-Count header to all blueprints find requests. Or even an X-Pagination-JSON header, or both.

Sails version support

It only supports Sails 1.x+

Basic Usage

npm install sails-count-middleware --save

Then in your config/http.js

middleware: {
// ....

    // require it with whatever name you want
    addCount: require('sails-count-middleware'),

    // then add it to the order[] array
    order: [
      // ...
      'addCount',
      // ...
     ]

Advanced Usage

You can create a policy, say we called it api/policies/addCount.js

 module.exports = require('sails-count-middleware').generate({
    // enable both for demo
    totalCountHeader: true
    paginationJsonHeader: true
 });

Then in config/policies.js you can specify which find call will get augmented with the count header.

UserController: {
    'find': ['isLoggedIn', 'addCount'],
}

Extra Options

There are options that you can change, just call the generate() function

    require('sails-count-middleware').generate({
        // if you want to add/remove an action i.e. 'user/search' or whatever
        // the array can contain a string for exact match or a regular expression for a pattern
        // if you use this options, the array you use will override the default, it will NOT concat
        // this is the default,
        // it will match all the usual :model/find, :model/:id/:association/populate
        actions: ['find', 'populate', /^.*\/(find|populate)$/]

        // you can rename the headers by passing a string
        // or disable them by setting them to false

        // default option value is true
        // default header name is 'X-Total-Count'
        totalCountHeader:  'X-Count', // this will enable and rename the header
        totalCountHeader: false, // this disable this header
        totalCountHeader: true, // this enable it with the default name

        // default option value is false
        // default header name is 'X-Pagination-JSON'
        paginationJsonHeader: 'X-PJSON', // this will enable and rename the header
        paginationJsonHeader: false, // this disable this header
        paginationJsonHeader: true, // this enable it with the default name

        // if the .count() calls fails, to throw an error or not
        silentError: false // default
    }),

Result

Then make a GET call to a find blueprint action, with any criteria, even with limit

Request

curl -sSL -D - localhost:1337/user?name=jane&limit=1

Response

HTTP/1.1 200 OK
X-Powered-By: Sails <sailsjs.com>
Content-Type: application/json; charset=utf-8
X-Total-Count: 4                          <---------
X-Pagination-JSON: {"count":4,"limit":1}  <---------
Content-Length: 614
ETag: W/"266-K6bjdxLpUMTlwLOyDQFTFJYi/pQ"
Date: Thu, 21 Dec 2017 17:18:22 GMT
Connection: keep-alive

[
  {..}  // Only 1 result though, since limit=1
]

Client side node

You can use this header however you like, but I recommend the following if you do not want to change the response.body that comes back from the sails server.

Just augment that array with a non-enumerable property, say we call it, __pagination__, this way when you iterate over or enumerate that array, that property won't be part of that iteration (in most cases), but you can still access it response.body.__pagination__.count

    // say you're using jQuery

    // .... somewhere in your app, call this once
    // this will intercept all the responses from the server
    // then augment the data response with a __pagination__, even if data is an array.
    $.ajaxSetup({
        success: (data, status, $xhr) => {
            let json = $xhr.getResponseHeader('x-pagination-json');
            if (json) {
                Object.defineProperty(data, '__pagination__', {
                    enumerable: false,
                    value: JSON.parse(json)
                });
            }
        }
    });

    // so when you make a GET call to find a list of things
    $.get('/api/users')
        .then((users) => {
            let {count, limit, skip, sort} = users.__pagination__;
            console.log(`users returned: ${users.length}, total users: ${count}`);
            users.forEach((user, i) => {
                console.log(`[index:${i}] user: ${user.name}`);
            });
        });