Global properties in Express & Handlebars

问题

I'm using Handlebars (using express3-handlebars) for templates and Passport for authentication in a NodeJS app. All is working great but I wondered if there is a way to pass the req.user object created by Passport to Handlebars globally.

So my header partial might look something like this:

<header>
    <h1>My Title</h1>
    {{#if user}}
        <p>Hello {{user.name}}</p>
    {{else}}
        <p>Please <a href='/login'>Log In</a></p>
    {{/if}}
</header>

As it stands I have to pass the user object explicitly with every page render:

app.get('/', function(req, res){
    res.render('home', {
        page_title: 'welcome',
        user: req.user
    }); 
});

This seems like the wrong way to go about it as I require it on every page, can I not just set it once and have all pages have access to it?

I can't do this when I instantiate Handlebars as it's dependent on the user being logged in with Passport, which won't always be the case.

Would creating a global 'page_options' object, appending and passing it to every render be the right solution or does Handlebars/Express have a way to handle this?

回答1:

I haven't personally used Passport before, but based on the Passport README and what I've done with other authentication schemes, this should work.

Express 3

app.configure(function() {
    app.use(passport.initialize());
    app.use(passport.session());
    app.use(function(req, res, next) {
        res.locals.user = req.user; // This is the important line

        next();
    });
    app.use(app.router);
});

Express 4

app.use(passport.initialize());
app.use(passport.session());
app.use(function(req, res, next) {
    res.locals.user = req.user; // This is the important line

    next();
});

Basically, right before rendering, your app.locals, res.locals, and the locals you pass into the render function (the second argument) all get combined and passed along to your view engine.

来源：https://stackoverflow.com/questions/22039970/global-properties-in-express-handlebars