Transform existing ApiContext with Mozu Event Request object header values

event-header-constants.js

//Additional headers not present in the Mozu Node SDK constants.js. 
//These headers are present on some Mozu Event Request objects, but are used mainly for metadata purposes.
module.exports = {
    TENANTDOMAIN: 'tenant-domain',
    LOCALE: 'locale',
    CURRENCY: 'currency',
    CORRELATION: 'correlation'
}

event-headers.txt

POST /mozu.events HTTP/1.1
x-vol-correlation: 45117118f1fb49af9fa0e1a26c5226cf
x-vol-tenant: 12080
x-vol-currency: 
x-vol-locale: 
x-vol-tenant-domain: t12080.sandbox.mozu.com
x-vol-site: 16771
x-vol-catalog: 2
x-vol-master-catalog: 1
Date: Fri, 22 Jan 2016 17:18:27 GMT
x-vol-hmac-sha256: 7usmeWKHe4BP35ZXZEHv+IU5SAh662qov3J13s2WaLg=
Content-Type: application/json; charset=utf-8
Host: f7fdfe78.ngrok.io
Content-Length: 208
X-Forwarded-Proto: https
X-Forwarded-For: 

modify-apiContext-with-event-headers.js

//We'll use the constants enum provided by the Mozu Node SDK to handle headers from Mozu event requests.
var constants = require('mozu-node-sdk/constants');
//Here, we alias the portion of the constants we'll use.
var headerPrefix = constants.headerPrefix;
var headers = constants.headers;

//We add additional header constants for optional values not needed by the Mozu Node SDK
var eventHeaderConstants = require('./event-header-constants');
//And using one of the utility functions in the Mozu Node SDK, 
//we expand the headers in constants.js to include additional event headers sent by Mozu events. 
var extend = require('mozu-node-sdk/utils/tiny-extend');
headers = extend(headers, eventHeaderConstants);


module.exports = function transformHeaders(requestHeaders, apiContext, cb) {
    //You can optionally choose to throw an error if there are no request headers. 
    //This should be a redundant check as you will have already run your SHA validation against the request. 
    if(requestHeaders) {
        for(var header in requestHeaders) {
            var headerValue = requestHeaders[header];
            //You can optionally choose to ignore all headers with empty string values. 
            if(headerValue !== '') {
                switch(header) {
                    //The cases covered by the Mozu Constants file --
                    //these values are sent as HTTP request headers when present on an apiContext
                    //when creating requests with the Mozu Node SDK
                    
                    case headerPrefix + headers.TENANT:
                        apiContext.context[headers.TENANT] = headerValue;
                        break;
                    
                    case headerPrefix + headers.SITE:
                        apiContext.context[headers.SITE] = headerValue;
                        break;
                    
                    case headerPrefix + headers.MASTERCATALOG:
                        apiContext.context[headers.MASTERCATALOG] = headerValue;
                        break;
                    
                    case headerPrefix + headers.CATALOG:
                        apiContext.context[headers.CATALOG] = headerValue;
                        break;
                    
                    //These headers are optional and more for your usage if needed.
                    //The values here will not be used in construction of request headers sent by the Mozu Node SDK,
                    //but you can utilize these values if needed later in your application.
                    case headerPrefix + headers.DATAVIEWMODE:
                        apiContext.context[headers.DATAVIEWMODE] = headerValue;
                        break;
                    
                    case headerPrefix + headers.VERSION:
                        apiContext.context[headers.VERSION] = headerValue;
                        break;
                    
                    //Now we'll handle the headers we added to the enum -- 
                    //these headers are also optional and we're only storing these
                    //in case our application needs any of these values later. 
                    case headerPrefix + headers.TENANTDOMAIN:
                        apiContext.context[headers.TENANTDOMAIN] = headerValue;
                        break;
                    
                    case headerPrefix + headers.LOCALE:
                        apiContext.context[headers.LOCALE] = headerValue;
                        break;
                    
                    case headerPrefix + headers.CURRENCY:
                        apiContext.context[headers.CURRENCY] = headerValue;
                        break;
                        
                    case headerPrefix + headers.CORRELATION:
                        apiContext.context[headers.CORRELATION] = headerValue;
                        break;
                        
                    default: 
                        break;     
                }
            }
        }
        return cb(null, apiContext);
    } else {
        return cb(new Error("Insufficient request headers"));
    }
}

mozu-events.js

var express = require('express');
var router = express.Router();
var apiContext = require('mozu-node-sdk/clients/platform/application')();
var isRequestValid = require('mozu-node-sdk/security/is-request-valid');
var transformContext = require('../util/modify-apiContext-with-event-headers');

/* GET /mozu.events  */
router.get('/', function(req, res, next) {
	res.render('events', { title: 'Eventing' });
});

router.use(function(req, res, next) {
    isRequestValid(apiContext.context, req, function(err) {
        if(err) {
            res.status(401);
            res.render('error', {message: err.message, error: err});
        } else {
            console.log("Validated request.");
            req.mozu = {isValid: true};
            next();
        }
    });    
});

/* POST against /mozu.events */
router.post('/', function(req, res, next) {
  transformContext(req.headers, apiContext, function(err, newApiContext) {
    if(err) {
        console.error(err);
        res.sendStatus(500);
    } else {
      console.log("Received POST request...");
      console.log(req.headers);
      console.log(req.body);
      console.log("Is Valid? " + (req.mozu.isValid ? "\u2713" : "x"));
      res.sendStatus(200);
    }
  });
});

module.exports = router;

public-api.js

module.exports = function transformHeaders(requestHeaders, apiContext, cb) {
}

require-statements.js

//We'll use the constants enum provided by the Mozu Node SDK to handle headers from Mozu event requests.
var constants = require('mozu-node-sdk/constants');
//Here, we alias the portion of the constants we'll use.
var headerPrefix = constants.headerPrefix;
var headers = constants.headers;

//We add additional header constants for optional values not needed by the Mozu Node SDK
var eventHeaderConstants = require('./event-header-constants');
//And using one of the utility functions in the Mozu Node SDK, 
//we expand the headers in constants.js to include additional event headers sent by Mozu events. 
var extend = require('mozu-node-sdk/utils/tiny-extend');
headers = extend(headers, eventHeaderConstants);

switch-statement.js

module.exports = function transformHeaders(requestHeaders, apiContext, cb) {
    //You can optionally choose to throw an error if there are no request headers. 
    //This should be a redundant check as you will have already run your SHA validation against the request. 
    if(requestHeaders) {
        for(var header in requestHeaders) {
            var headerValue = requestHeaders[header];
            //You can optionally choose to ignore all headers with empty string values. 
            if(headerValue !== '') {
                switch(header) {
                    //The cases covered by the Mozu Constants file --
                    //these values are sent as HTTP request headers when present on an apiContext
                    //when creating requests with the Mozu Node SDK
                    
                    case headerPrefix + headers.TENANT:
                        apiContext.context[headers.TENANT] = headerValue;
                        break;
                    
                    case headerPrefix + headers.SITE:
                        apiContext.context[headers.SITE] = headerValue;
                        break;
                    
                    case headerPrefix + headers.MASTERCATALOG:
                        apiContext.context[headers.MASTERCATALOG] = headerValue;
                        break;
                    
                    case headerPrefix + headers.CATALOG:
                        apiContext.context[headers.CATALOG] = headerValue;
                        break;
                    
                    //These headers are optional and more for your usage if needed.
                    //The values here will not be used in construction of request headers sent by the Mozu Node SDK,
                    //but you can utilize these values if needed later in your application.
                    case headerPrefix + headers.DATAVIEWMODE:
                        apiContext.context[headers.DATAVIEWMODE] = headerValue;
                        break;
                    
                    case headerPrefix + headers.VERSION:
                        apiContext.context[headers.VERSION] = headerValue;
                        break;
                    
                    //Now we'll handle the headers we added to the enum -- 
                    //these headers are also optional and we're only storing these
                    //in case our application needs any of these values later. 
                    case headerPrefix + headers.TENANTDOMAIN:
                        apiContext.context[headers.TENANTDOMAIN] = headerValue;
                        break;
                    
                    case headerPrefix + headers.LOCALE:
                        apiContext.context[headers.LOCALE] = headerValue;
                        break;
                    
                    case headerPrefix + headers.CURRENCY:
                        apiContext.context[headers.CURRENCY] = headerValue;
                        break;
                        
                    case headerPrefix + headers.CORRELATION:
                        apiContext.context[headers.CORRELATION] = headerValue;
                        break;
                        
                    default: 
                        break;     
                }
            }
        }
        return cb(null, apiContext);
    } else {
        return cb(new Error("Insufficient request headers"));
    }
}