express-param

Fetch Express.js Request parameters Middleware

About

You can reduce amount of code. It can remove redundant code and generate high readability.

See below.

• may be existing

function route(req, res, next) {
  var id = req.params.id
    , count = req.param('count') ? parseInt(req.param('count'), 10) : 10
    , odrer = req.param('order')
    , type = req.param('type')
    , name = req.param('name')
    , since = req.param('since')
    , from = req.param('from')
    , res_id = req.param('res_id');

  if (!res_id) return next(400);
  if (!name) return next(400);
  if (!order) order = 'desc';
  if (!type) type = 'integer';

  // some code...
}

• after using this

function route(req, res, next) {
  var requiredParams = ['{id}', 'name', 'res_id']
    , optionalParams = ['number:count|=10', 'order|=desc', 'type|=integer', 'since', 'from']
    , options;

  options = req.fetchParamter(requiredParams, optionalParams);

  if (req.checkParamErr(options)) return next(options);

	return res.send(options);
}

parameter syntax

I was inspired by Spring Framework and Flask.

• required parameter
  • Array
  • [element1, element2, element3, ...]
  • type:{parameter_name}
    • type: type is optional(default string). number or string. return variable with type.
    • {parameter_name}: {} is optional. but parameter name is required. if it include {}, it means that this is path variable
    • ex) ['number:{flitto_id}], 'string:req_id', 'res_id']
• optional parameter
  • Array
  • [element1, element2, element3, ...]
  • type:parameter_name|=default_value
    • type: type is optional(default string). number or string. return variable with type.
    • parameter_name: required.
    • default_value: optional. if request object do not have specified parameter then assign this default value.
    • ex) ['number:count', 'order', 'string:res_list|=Y']

Example

Here is an simple example.

var express = require('express');
var fetcher = require('express-param');
var app = express();
app.use(fetcher());

app.get('/path', function(req, res, next) {
  var requiredParams = ['id'];
  var optionalParams = ['count'];
  var options = req.fetchParamter(requiredParams, optionalParams);

  if (req.checkParamErr(options)) return next(options);

  return res.send(options);
});

Here is another example with express-param syntax

var fetcher = require('express-param');
var app = express();
app.use(fetcher());

app.get('/path/:id/', function(req, res, next) {
  var requiredParams = ['string:{id}'];
  var optionalParams = ['number:count|=10, order|=desc'];
  var options = req.fetchParamter(requiredParams, optionalParams);

  if (req.checkParamErr(options)) return next(options);

  //options values is below.
  /*
  {
    id: '10',
    count: 10
    order: 'desc'
  }
  */
  return res.send(options);
});

Another example

Custom request key name belong to req property of express

var express = require('express');
var fetcher = require('express-param');
var app = express();
app.use(fetcher({
  'ipaddr': 'ip'
}));

app.get('/path', function(req, res, next) {
  var requiredParams = ['id'];
  var optionalParams = ['count', 'ipaddr'];
  var options = req.fetchParamter(requiredParams, optionalParams);

  if (options.err) return next(options.err);

  /*
  options.ipaddr is equal to req.ip
  */
  return res.send(options.params);
});

API

• fetchParameter(required[, optional])

  fetch parameter of required and optional

Add ON

• fetch geographic information

  It can fetch country information from remote address!

var addOnOpt = {
  geoip: {
    keyName: 'headers.x-forwarded-for'
  }
};
app.use(fetcher({
  'ipaddr': 'ip'
}, addOnOpt));

////// ....

console.log(req.param('x-fetcher-geoinfo'))
//// output
{
  country:
  {
    country_name: 'United States',
    country_code: 'US',
    country_code3: 'USA',
    continent_code: 'NA'
  } 
}  
///

• fetch detail imsi information by mnc, mcc code

  It can generate detail imsi(country, operator...) information by mcc, mnc code!

var addOnOpt = {
  imsi: true
};
app.use(fetcher({
  'ipaddr': 'ip'
}, addOnOpt));

////// ....

// url maybe hostname/api?mnc=11&mcc=450. if only exist mcc then results array length may be greater than 1.

console.log(req.param('x-imsi'))
//// output
[{
  country_name: 'South Korea',
  country_code: 'KR',
  mcc: '450',
  mnc: '11',
  brand: 'SKTelecom',
  operator: 'Korea Cable Telecom(t-plus), Eco-mobile',
  status: 'Operational',
  bands: 'UMTS 2100'
}]
///

Contributing

We'd love your contributions! Please send us Pull Requests. Also, read the contribution guidelines.

LICENSE

MIT

---

This product includes GeoLite data created by MaxMind, available from http://www.maxmind.com