@sap/hdbext/lib/middleware.js

Hana-client extension library and utility functions for using SAP HANA in node.js

'use strict';

var _ = require('lodash');
var debug = require('debug')('hdbext:middleware');
var connOptions = require('./conn-options');
var clientFactory = require('./client-factory');

exports.middleware = function middleware(hanaService) {
  var globalOptions = _.extend({}, connOptions.getGlobalOptions(), hanaService);

  return function db(req, res, next) {
    var requestOptions = connOptions.getRequestOptions(req);
    var options = _.extend({}, globalOptions, requestOptions);

    clientFactory.createConnection(options, function (err, client) {
      if (err) {
        err.status = 500;
        return next(err);
      }

      req.db = client;

      var end = res.end;
      res.end = function () {
        var resEndArgs = arguments;

        debug('Cleanup triggered');
        req.db.close(function (err) {
          if (err) {
            debug('Error while closing connection.', err);
          }
          delete req.db;
          res.end = end;
          res.end.apply(res, resEndArgs);
        });
      };

      next();
    });
  };

};