express api json resposder

responder_middleware.js

'use strict'

/*
 * API middleware
 *
 * Adds shortcut methods for JSON API responses (inspired by KeystoneJS) :
 *
 * `res.apiResponse(data)`
 * `res.apiError(key, err, msg, code)`
 * `res.apiNotFound(err, msg)`
 * `res.apiNotAllowed(err, msg)`
 */

const winston = require('winston')

const logger = new winston.createLogger({
  transports: [
    new winston.transports.Console({
      timestamp: true,
      level: 'debug',
      handleExceptions: true,
      json: false,
      colorize: true
    })
  ],
  exitOnError: false
})

logger.stream = {
  write: (message) => logger.debug(message.replace(/\n$/, ''))
}

const initAPI = (req, res, next) => {
  // Utility methods
  res.apiResponse = data => {
    if (req.query.callback) {
      res.jsonp(data)
    } else {
      res.json(data)
    }
  }

  res.apiError = (status, err, info) => {
    if (err) {
      const ip = (req.ip) ? req.ip : 'anonymous'
      logger.error(
        `user=${ip} - method=${req.method} - url=`
        + `${req.originalUrl} - status=${status} - message=${err.message}`,
        { error: err }
      )
    }

    res.status(status || 500)
    res.apiResponse({
      success: false,
      message: err.message || info
    })
  }

  // Handler for HTTP response codes : errors
  res.apiNotFound = (err, info) => {
    res.apiError(404, err, info || 'Data not found')
  }

  res.apiBadRequest = (err, info) => {
    res.apiError(400, err, info || 'Bad request')
  }

  res.apiUnauthorized = (err, info) => {
    res.apiError(401, err, info || 'Unauthorized operation')
  }

  res.apiForbidden = (err, info) => {
    res.apiError(403, err, info || 'Request forbidden')
  }

  res.apiNotAllowedMethod = (err, info) => {
    res.apiError(405, err, info || 'Method not allowed')
  }

  next()
}

module.exports = { initAPI }