用户登录后流星重新渲染模板

Question

Ok so im using Facebook API graph when the user is logging in using facebook im getting the user friend list + friends pictures like that:

Template.user_loggedout.events({
    "click #fb": function (e, tmp) {
        Meteor.loginWithFacebook({
            requestPermissions: ['user_likes',
                'friends_about_me',
                'user_birthday',
                'email',
                'user_location',
                'user_work_history',
                'read_friendlists',
                'friends_groups',
                'user_groups']
        }, function (err) {
            if (err) {
                console.log("error when login with facebook " + err);
            } else {
                FB.api('/' + Meteor.user().services.facebook.id + '/friends', { fields: 'name,picture' }, function (response) {
                    if (response && response.data) {
                        friends = response.data
                    }
                })
            }
        });
    }

and as expected i get friends array inside there are objects(represented as friends). at some point when the user clicks a link i want to show the user his friends list. so i got this html:

Template.add_friends.helpers({
    friends_list: friends
});

template name="add_friends">
    <div class="friends_Page">
           {{#each friends_list}}
        <li>{{name}}</li>
        {{/each}}
    </div>
</template>

the problem is that the friends object gets updated after the app as started and when the user clicked the login button using facebook. so how to re-render when i get the callback from facebook graph api? i dont want to store the friends in database (its already available thanks to facebook )

Answer 1

The most natural way to force a redraw when data is changed is to use a dependency on that data.

var friends = [];
var friends_dep = new Deps.Dependency();

Template.myTemplate.friends_list = function() {
    friends_dep.depend();    /* Causes the helper to rerun when data changes */
    return friends;
};

...

function callback() {
    ...
    friends = response.data;
    friends_dep.changed();    /* Call this after you set the new data */
}