Send variables to all routes in exressjs - node.js

Question

Using nodejs/expressjs to build the APIs for my web app, I want to send some variables to all APIs, such as site title and description and so on.
I stumbled upon the old solution using dynamicHelper() which is no longer in use. What is the new approach to do so?

Answer 1

Easiest thing is to just put in some middleware that attaches it to the response object as locals (those will show up in your views automatically). Something like:
app.use(function(req,res,next) {
res.locals = {
title : 'your title',
description : 'your description'
};
return next();
});
** EDIT to account for what the API endpoints have to do
Since each endpoint is likely responsible for its own object, you would also do something like:
app.get('/whatever', function(req,res){
var json = {};
// do whatever to build your json
json.metadata = res.locals; // or whatever the common stuff is
res.send(json);
}
This keeps all your 'common' stuff in one part of the json response.

Answer 2

Since you mention you are not using any view engine in expressjs, I am assuming you are just relying on angularJS to do the client side redering. You can pass those server side data to the http header, and then read them from the client side. To do that, in your router, you can do this,
app.use(function(req,res,next) {
res.set({
'title': 'my title',
'description': '123'
});
next();
});
Then in your angularJS app, you can read them from the http header.

Answer 3

You should try interceptors in your front end side(angular js) to send multiple variable with each request api.
In following code i am sending title and description in headers.
module.factory('varInfoInterceptors', function($q) {
var sendInfoInjector = {
request: function(config) {
config.headers['x-headers-title'] = 'Test title';
config.headers['x-headers-desc'] = 'This is test site';
return config;
}
};
return sendInfoInjector;
});
module.config(['$httpProvider', function($httpProvider) {
$httpProvider.interceptors.push('varInfoInterceptors');
}]);
You can get these values in server side(nodejs/expressjs) by just calling req.headers express routes
Thanks,
Dinesh