Menquery NPM | npm.io

Menquery

Querystring parser middleware for MongoDB, Express and Nodejs

Install

npm install --save menquery

Examples

Pagination

Menquery has a default schema to handle pagination. This is the most simple and common usage.

var menquery = require('menquery');

app.get('/posts', menquery.middleware(), function(req, res) {
  var query = req.menquery;

  Post.find(query.query, query.select, query.cursor).then(function(posts) {
    // posts are proper paginated here
  });
});

User requests /posts?page=2&limit=20&sort=-createdAt req.menquery will be:

req.menquery = {
  query: {},
  select: {},
  cursor: {
    limit: 20, 
    skip: 20, 
    sort: {createdAt: -1}
  }
}

User requests /posts?q=term&select=title,desc req.menquery will be:

req.menquery = {
  query: {
    keywords: /term/i
  },
  select: {
    title: 1,
    desc: 1
  },
  cursor: {
    // defaults
    limit: 30, 
    skip: 0, 
    sort: {name: 1}
  }
}

User requests /posts?select=-title&sort=name,-createdAt req.menquery will be:

req.menquery = {
  query: {},
  select: {
    title: 0
  },
  cursor: {
    limit: 30, 
    skip: 0, 
    sort: {
      name: 1,
      createdAt: -1
    }
  }
}

Custom schema

You can define a custom schema, which will be merged into menquery default schema (explained above).

var menquery = require('menquery');

app.get('/posts', menquery.middleware({
  after: {
    type: Date,
    paths: ['createdAt']
    operator: '$gte'
  }
}), function(req, res) {
  Post.find(req.menquery.query).then(function(posts) {
    // ...
  });
});

User requests /posts?after=2016-04-23 req.menquery will be:

req.menquery = {
  query: {
    createdAt: {$gte: 1461369600000}
  },
  select: {},
  cursor: {
    // defaults
    limit: 30, 
    skip: 0, 
    sort: {name: 1}
  }
}

Reusable schemas

You can create reusable schemas as well. Just instantiate a menquery.Schema object.

var menquery = require('menquery');

var schema = new menquery.Schema({
  tags: {
    type: [String],
  }
});

// user requests /posts?tags=world,travel
// req.menquery.query is {tags: {$in: ['world', 'travel']}}
app.get('/posts', menquery.middleware(schema));
app.get('/articles', menquery.middleware(schema));

Advanced schema

var menquery = require('menquery');

var schema = new menquery.Schema({
  active: Boolean, // shorthand to {type: Boolean}
  sort: '-createdAt', // shorthand to {type: String, default: '-createdAt'}
  term: {
    type: RegExp,
    paths: ['title', 'description'],
    bindTo: 'search' // default was 'query'
  },
  with_picture: {
    type: Boolean,
    paths: ['picture'],
    operator: '$exists'
  }
}, {
  page: false, // disable default parameter `page`
  limit: 'max_items' // change name of default parameter `limit` to `max_items`
});

app.get('/posts', menquery.middleware(schema), function(req, res) {
  // user requests /posts?term=awesome&with_picture=true&active=true&max_items=100
  // req.menquery.query is {picture: {$exists: true}, active: true}
  // req.menquery.cursor is {limit: 100, sort: {createdAt: -1}}
  // req.menquery.search is {$or: [{title: /awesome/i}, {description: /awesome/i}]}
});

Dynamic advanced schema

var menquery = require('menquery');
var schema = new menquery.Schema();

schema.formatter('scream', function(scream, value, param) {
  if (scream) {
    value = value.toUpperCase() + '!!!!!!!';
  }
  return value;
});

schema.param('text', null, {type: String}); // {type: String}
schema.param('text').option('scream', true); // {type: String, scream: true}
schema.param('text').value('help');
console.log(schema.param('text').value()); // HELP!!!!!!!

schema.validator('isPlural', function(isPlural, value, param) {
  return {
    valid: !isPlural || value.substr(-1) === 's',
    message: param.name + ' must be in plural form.'
  };
});

schema.param('text').option('isPlural', true); // {type: String, scream: true, isPlural: true}
console.log(schema.validate()); // false
schema.param('text', 'helps');
console.log(schema.validate()); // true
console.log(schema.param('text').value()); // HELPS!!!!!!!

schema.parser('elemMatch', function(elemMatch, value, path, operator) {
  if (elemMatch) {
    value = {[path]: {$elemMatch: {[elemMatch]: {[operator]: value}}}};
  }
  return value;
});

schema.param('text', 'ivegotcontrols');
console.log(schema.param('text').parse()); // {text: 'IVEGOTCONTROLS!!!!!!!'}

schema.param('text').option('elemMatch', 'prop');
console.log(schema.param('text').parse()); // {text: {$elemMatch: {prop: {$eq: 'IVEGOTCONTROLS!!!!!!!'}}}}

Error handling

// user requests /posts?category=world
var menquery = require('menquery');

var schema = new menquery.Schema({
  category: {
    type: String,
    enum: ['culture', 'general', 'travel']
  }
});

app.get('/posts', menquery.middleware(schema));

app.use(function(err, req, res, next) {
  res.status(400).json(err);
});

Response body will look like:

{
  "valid": false,
  "name": "enum",
  "enum": ["culture", "general", "travel"],
  "value": "world",
  "message": "category must be one of: culture, general, travel"
}