Access connect-flash messages in angular.js

I'm adapting some code that presupposes a traditional non-SPA page load, and displays flash messages to the user generated by connect-flash middleware. It does this by passing in an object that is rendered in a EJS file.

My app is angular and I have no templating engine on the backend, and would like to avoid using one. How can I make angular aware of these flash messages?

Here is the context: passportjs redirects on error to /signup

// process the signup form
app.post('/signup', passport.authenticate('local-signup', {
    successRedirect : '/profile', // redirect to the secure profile section
    failureRedirect : '/signup', // redirect back to the signup page if there is an error
    failureFlash : true // allow flash messages
}));

Thanks for any help!

My solution was to create an EJS page whose only purpose was to extract the connect-flash data and redirect the browser to the specified route with data appended as querystring. 

// process the signup form
app.post('/signup', passport.authenticate('local-signup', {
    successRedirect : '/profile', // redirect to the secure profile section
    failureRedirect : '/signup', // redirect back to the signup page if there is an error
    failureFlash : true // allow flash messages
}));

app.get('/signup', function(req, res) {
    // render the page and pass in any flash data if it exists
   res.render('redirect.ejs', {redirect_url: "/?route=/signup&message="+req.flash('signupMessage')});
});

redirect.ejs

<html>
<meta http-equiv="refresh" content="0;<% if (redirect_url) { %><%=redirect_url %><% } %>" />
</html>

angular controller

app.controller("Index", function ($scope, $route, $routeParams,$location) {
 var route= $routeParams.route, msg=$routeParams.message;
    if (route) {
        if ($location.$$search.route) {
            delete $location.$$search.route;
            $location.$$compose();
        }
        console.log(route, msg);
        $location.path(route);
    }

});

It could have been worse.