want to show average rating and total reviews of product - mongodb

Question

I am beginner and following a tutorial to make a review products application and rather than just copy pasting the code trying to do some experiment with it to get more depth knowledge. I have two questions regarding my app
1) I added some more functionality to my app and wrote some code in includes.js and reviews.html to show average rating and total review of a product .How i can show average rating and number of reviews for the product thats been clicked?
2) I added product categories list to show in side bar(e.g Electronics , Fashion, Books) through chrome console by adding them manually e.g like this
Categories.insert({name:'Eelctronics',slug:'electronics'});
So i have deployed this app on free meteor hosting and every time some one run this app he has to write this above code manually in chrome console to get list of categories.Even if some one clone my project from gitHub also can not see list of categories in left side bar and he also have to write the same code in console.So what is the solution for it how i can show list of categories in my side bar with out writing above code in console?
You can check gitHub repository for source code.

Answer 1

1) Show average rating and review count
<p>Average Rating: <img class="stars" src="/img/star{{averageRating}}.png"> ({{countReviews}})</p>
I've moved this code into reviews.helpers section
Template.reviews.helpers({
'reviews': function () {
return Reviews.find({productId: Router.current().data()._id})
},
countReviews: function(){
return Reviews.find({productId: Router.current().data()._id}).count();
},
averageRating: function() {
var reviews = Reviews.find({productId: Router.current().data()._id}); //get all reviews for productId
//var ratings = reviews.map(function(player){return player.score;}); // get just the ratings, or use _.pluck
var ratings = _.pluck(reviews, 'ratings'); // get just the ratings i.e. [1, 5, 3, 2, 5]
var sum = ratings.reduce(function(pv, cv){return pv + cv;}, 0); //sum ratings i.e. 14
var avg = sum / ratings.length; // i.e. 2.8
return Math.round(2.8); // round avg to ensure only integer values are returned
},
})
2) Seed database
Docs Add a Meteor.startup block to seed database
// On server startup, if the database is empty, create some initial data.
if (Meteor.isServer) {
Meteor.startup(function () {
if (Categories.find().count() === 0) {
Categories.insert({name:'Electronics',slug:'electronics'});
Categories.insert({name:'Fashion',slug:'fashion'});
Categories.insert({name:'Books',slug:'books'});
}
});
}