Meteor collection lookup on router level

Question

I'm building an app that has versions of pages. I'd like users to be able to visit the page without having to specify the version they wish to start working with. In case no version is specified in the URL, I'd like to look up the latest version of that page and redirect to it.

The problem I'm having is that I can't do any collection lookups on the router level to figure out what version I'm looking for because the collections simply aren't there.

Here's my code so far:

Router.route('page', {
    path: '/page/:slug/:version?',
    onBeforeAction: function() {
        var versionId = this.params.version;

        if (!versionId) {
            console.log('no version! oh noes!');

            var p = Pages.find({slug: this.params.slug});
            var newestVersion = Versions.findOne({page: p._id}, {sort: {createdAt: -1}});
            versionId = newestVersion._id;

            Router.redirect('page', this.params.slug, versionId);
        }

        this.next();
    },
    waitOn: function() {
        return Meteor.subscribe('page', this.params.slug, this.params.state);
    },
    data: function() {
        return {
            page: Pages.findOne({slug: this.params.slug}),
            version: Versions.findOne(this.params.version)
        }
    }
});

Any help or insights are very much appreciated!

Answer 1

Here's the solution I found. The problem is that the onBeforeAction didn't actually wait for the waitOn unless you tell it to.

onBeforeAction: function() { 
    if (this.ready()) { 
        if (!this.params.version) { 
            var p = Pages.findOne({slug: this.params.slug}), 
                sortedVersions = _.sortBy(Versions.find({page: p._id}).fetch(), function(s) { 
                    return v.createdAt; 
                });

            var newest_version_id = sortedVersions[0]._id;
            this.redirect('page', {slug: this.params.slug, state: newest_version_id});
        }

        this.next();
    }
}

I think the key is in the this.ready() check which is only true when all subscriptions in the waitOn are true. I assumed all this happened automagically by simply using the waitOn.