express-expose
Expose helpers and local variables to the client-side.
Install
npm install -S express-expose
Usage
var express = require('express');
var expose = require('express-expose');
app = expose(app);
app.expose(...);
[email protected]
and [email protected]
:
var express = require('express');
var expose = require('express-expose');
app.expose(...);
Versions
[email protected]
(useexpress-expose
at>= 0.3.4
)[email protected]
(useexpress-expose
at>= 0.2.3
and<= 0.3.3
)[email protected]
(useexpress-expose
at<= 0.2.2
)
Examples
Exposing Objects
A common use-case for exposing objects to the client-side would be exposing some properties, perhaps the express configuration. The call to app.expose(obj)
below defaults to exposing the properties to app.*
, so for example app.views
, app.title
, etc.
app.set('views', __dirname + '/views');
app.set('view engine', 'jade');
app.set('title', 'Example');
app.set('default language', 'en');
app.expose(app.settings);
Another use-case would be exposing helper methods, perhaps the same ones as you are currently exposing to templates. Below we expose the math
object as utilities to our templates, as well as the client-side. Within a template we would call add(1,2)
, and on the CS we would call utils.add(1,2)
, since we have passed the namespace "utils".
var math = { add: function(a,b){ return a + b; } };
app.expose(math, 'utils').helpers(math);
Sometimes you might want to output to a different area, so for this we can pass an additional param "languages" which tells express which buffer to write to, which ends up providing us with the local variable "languages" in our template, where the default is "javascript". The "app" string here is the namespace.
app.expose({ en: 'English', fr: 'French' }, 'app', 'languages');
You'll then want to output the default buffer (or others) to your template, in Jade this would look something like:
script!= javascript
And in EJS:
<script><%- javascript %></script>
Raw JavaScript
It is also possible to expose "raw" javascript strings.
app.expose('var some = "variable";');
Optionally passing the destination buffer, providing us with the "head" local variable, instead of the default of "javascript".
app.expose('var some = "variable";', 'head');
Exposing Functions
Exposing a named function is easy too, simply pass it in with an optional buffer name for placement within a template much like above.
app.expose(function someFunction(){
return 'yay';
}, 'foot');
Self-Calling Functions
Another alternative is passing an anonymous function, which executes itself, creating a "wrapper" function.
app.expose(function(){
function notify() {
alert('this will execute right away :D');
}
notify();
});
Request-Level Exposure
Finally we can apply all of the above at the request-level as well, below we expose "app.current.user" as { name: 'tj' }
, for the specific request only.
app.get('/', function(req, res){
var user = { name: 'tj' };
res.expose(user, 'app.current.user');
res.render('index', { layout: false });
});