mongoose-aggregate-paginate-v2

A cursor based custom aggregate pagination library for Mongoose with customizable labels.

If you are looking for basic query pagination library without aggregate, use this one mongoose-paginate-v2

Installation

npm install mongoose-aggregate-paginate-v2

Usage

Adding the plugin to a schema,

var mongoose = require('mongoose');
var aggregatePaginate = require('mongoose-aggregate-paginate-v2');

var mySchema = new mongoose.Schema({ 
    /* your schema definition */ 
});

mySchema.plugin(aggregatePaginate);

var myModel = mongoose.model('SampleModel',  mySchema); 

and then use model aggregatePaginate method,

// as Promise

var myModel = require('/models/samplemodel');

const options = {
    page: 1,
    limit: 10
};

var myAggregate = myModel.aggregate();
myModel.aggregatePaginate(myAggregate, options).then(function(results){
    console.log(results);
}).catch(function(err){
    console.log(err);
})

// as Callback

var myModel = require('/models/samplemodel');

const options = {
    page: 1,
    limit: 10
};

var myAggregate = myModel.aggregate();
myModel.aggregatePaginate(myAggregate, options, function(err, results) {
    if(err) {
        console.err(err);
    else { 
        console.log(results);
    }
})

Model.aggregatePaginate([aggregateQuery], [options], [callback])

Returns promise

Parameters

• [aggregate-query] {Object} - Aggregate Query criteria. Documentation
• [options] {Object}
  • [sort] {Object | String} - Sort order. Documentation
  • [page=1] {Number} - Current Page.
  • [limit=10] {Number} - Docs. per page.
  • [customLabels] {Object} - Developers can provide custom labels for manipulating the response data.
  • [allowDiskUse] {Bool} - To enable diskUse for bigger queries. (default=false)
• [callback(err, result)] - (Optional) If specified the callback is called once pagination results are retrieved or when an error has occurred.

Return value

Promise fulfilled with object having properties:

• docs {Array} - Array of documents
• totalDocs {Number} - Total number of documents that match a query
• limit {Number} - Limit that was used
• page {Number} - Current page number
• totalPages {Number} - Total number of pages.
• hasPrevPage {Bool} - Availability of prev page.
• hasNextPage {Bool} - Availability of next page.
• prevPage {Number} - Previous page number if available or NULL
• nextPage {Number} - Next page number if available or NULL
• pagingCounter {Number} - The starting sl. number of first document.

Please note that the above properties can be renamed by setting customLabel attribute.

Sample Usage

Return first 10 documents from 100

const options = {
    page: 1,
    limit: 10
};

// Define your aggregate.
var aggregate = Model.aggregate();

Model.aggregatePaginate(aggregate, options)
    .then(function(result) {
        // result.docs
        // result.totalDocs = 100
        // result.limit = 10
        // result.page = 1
        // result.totalPages = 10    
        // result.hasNextPage = true
        // result.nextPage = 2
        // result.hasPrevPage = false
        // result.prevPage = null
    })
    .catch(function(err){
        console.log(err);
    });

With custom return labels

Now developers can specify the return field names if they want. Below are the list of attributes whose name can be changed.

• totalDocs
• docs
• limit
• page
• nextPage
• prevPage
• totalPages
• hasNextPage
• hasPrevPage
• pagingCounter

You should pass the names of the properties you wish to changes using customLabels object in options. Labels are optional, you can pass the labels of what ever keys are you changing, others will use the default labels.

Same query with custom labels

const myCustomLabels = {
    totalDocs: 'itemCount',
    docs: 'itemsList',
    limit: 'perPage',
    page: 'currentPage',
    nextPage: 'next',
    prevPage: 'prev',
    totalPages: 'pageCount',
    hasPrevPage: 'hasPrev',
    hasNextPage: 'hasNext',
    pagingCounter: 'pageCounter'
};

const options = {
    page: 1,
    limit: 10,
    customLabels: myCustomLabels
};

// Define your aggregate.
var aggregate = Model.aggregate();

Model.aggregatePaginate(aggregate, options, function(err, result) {
    if(!err) {
        // result.itemsList [here docs become itemsList]
        // result.itemCount = 100 [here totalDocs becomes itemCount]
        // result.perPage = 10 [here limit becomes perPage]
        // result.currentPage = 1 [here page becomes currentPage]
        // result.pageCount = 10 [here totalPages becomes pageCount]
        // result.next = 2 [here nextPage becomes next]
        // result.prev = null [here prevPage becomes prev]

        // result.hasNextPage = true [not changeable]
        // result.hasPrevPage = false [not changeable]
    } else {
        console.log(err);
    };

License

MIT