Little snippet to set canonical links in AngularJS. Note. this will only work with crawlers if you implement some sort of interceptor and return fully rendered html/js to the crawler i.e. using PhantomJS

Angular canonical tags

$rootScope.$watch('canonical', function(newVal){
    if(newVal != '') {
        var link = angular.element('<link>');
        link.attr('rel', 'canonical');
        link.attr('href', newVal);

        angular.element('head').append(link);
    }
})

$rootScope.canonical = 'http://google.com';