@cmddevelop/query-parameters

Converts URL query string into a Mongoose friendly object. Create and object with key values for Mongoose options and filtering.

This library was build using this mongoose-query-parser as a starting point. Thank you for the good work. It was used as a starting point to develop this for a custom application.

Features

• Supports the most of MongoDB operators ($in, $regexp, $exists) and features including skip, sort, limit, population
• Additionally, there is a key word of page that can be applied in order to work with mongoose-paginate
• Auto type casting of Number, RegExp, Date, Boolean and null
• String templates/predefined queries (i.e. firstName=${my_vip_list})
• Allows customization of keys and options in query string

Installation

npm i @cmddevelop/query-parameters

Usage

API

import { QueryParser } from '@cmddevelop/query-parameters';

const parser = new QueryParser(options?: ParserOptions)
parser.parse(query: string, predefined: any) : QueryOptions

Arguments

• ParserOptions: object for advanced options (See below) [optional]
• query: query string part of the requested API URL (ie, firstName=John&limit=10). Works with already parsed object too (ie, {status: 'success'}) [required]
• predefined: object for predefined queries/string templates [optional]

Returns

• QueryOptions: object contains the following properties:
  • filter which contains the query criteria
  • populate which contains the query population. Please see Mongoose Populate for more details
  • select which contains the query projection
  • sort, skip, limit which contains the cursor modifiers for paging purpose

Filtering operators

MongoDB	URI	Example	Result
$eq	key=val	type=public	{filter: {type: 'public'}}
$gt	key>val	count>5	{filter: {count: {$gt: 5}}}
$gte	key>=val	rating>=9.5	{filter: {rating: {$gte: 9.5}}}
$lt	key<val	createdAt<2017-10-01	{filter: {createdAt: {$lt: 2017-09-30T14:00:00.000Z}}}
$lte	key<=val	score<=-5	{filter: {score: {$lte: -5}}}
$ne	key!=val	status!=success	{filter: {status: {$ne: 'success'}}}
$in	key=val1,val2	country=GB,US	{filter: {country: {$in: ['GB', 'US']}}}
$nin	key!=val1,val2	lang!=fr,en	{filter: {lang: {$nin: ['fr', 'en']}}}
$exists	key	phone	{filter: {phone: {$exists: true}}}
$exists	!key	!email	{filter: {email: {$exists: false}}}
$regex	key=/value/<opts>	email=/@gmail\.com$/i	{filter: {email: /@gmail.com$/i}}
$regex	key!=/value/<opts>	phone!=/^06/	{filter: {phone: { $not: /^06/}}}

For more advanced usage ($or, $type, $elemMatch, etc.), pass any MongoDB query filter object as JSON string in the filter query parameter, ie:

Populate operators

• Useful to populate sub-document(s) in query. Works with MongooseJS. Please see Mongoose Populate for more details
• Allows to populate only selected fields
• Default operator key is populate

Skip / Limit / Page operators

• Useful to limit the number of records returned
• Default operator keys are skip or page, and limit