How to subscribe properly on angular-meteor - angularjs

Question

I'm new to angular-meteor and trying to make an application similar to Reddit for excercise. But I'm not sure what's the right approach to subscribe and publish. Here's my code.
angular.module('app')
.config(($stateProvider) ->
$stateProvider
.state('boards-list',
url: '/board'
templateUrl: 'client/boards/boards-list.view.ng.html'
controller: 'BoardsListCtrl'
)
.state('board-detail',
url: '/board/:symbol'
templateUrl: 'client/boards/board-detail.view.ng.html'
controller: 'BoardDetailCtrl'
)
)
I want to show popular post on /board and if you go to specific board I want to list all the post in the board.
This is board-list controller
angular.module('app')
.controller('BoardsListCtrl', ($scope, $meteor, $modal, $log) ->
$meteor.subscribe('getPopularPosts')
$meteor.subscribe('getAllBoards')
$scope.boards = $scope.$meteorCollection(->
Boards.find({})
)
$scope.posts = $scope.$meteorCollection(->
Posts.find({}, _.defaults(DEFAULT_QUERY_OPTIONS, limit: 5))
)
$scope.getHref = (link) -> if link then "http://#{link}" else "#"
$scope.remove = (board) ->
$scope.boards.remove(board)
$scope.open = ->
modalInstance = $modal.open(
templateUrl: 'client/common/modal-new-board.view.ng.html'
controller: 'ModalNewBoardCtrl'
)
)
And this is board-detail controller
angular.module('app')
.controller('BoardDetailCtrl', ($scope, $stateParams, $meteor, $modal) ->
boardSymbol = $stateParams.symbol
$scope.posts = []
$scope.$meteorSubscribe('getBoardBySymbol', boardSymbol)
$scope.board = $meteor.object(Boards, symbol: boardSymbol, false)
$scope.$meteorSubscribe('getPostsByBoard', boardSymbol)
$scope.posts = $scope.$meteorCollection(->
Posts.find(board: boardSymbol, DEFAULT_QUERY_OPTIONS)
)
$scope.open = ->
modalInstance = $modal.open(
templateUrl: 'client/common/modal-post.view.ng.html'
controller: 'ModalPostCtrl'
resolve:
symbol: -> $scope.board.symbol
)
)
My question is if I write Posts.find({}, DEFAULT_QUERY_OPTIONS) for boardDetailCtrl's $scope.posts, It actually shows all the posts as if the routes is /board when the state is changed. When you directly access the route like http://localhost:3000/angular it gets proper posts. Not sure why this is happening but I changed it to Posts.find({board: boardSymbol}, DEFAULT_QUERY_OPTIONS) Then it works as expected.
Considering that I only subscribe getPostByBoard which is about getting post only at given board, I should be able to get only a few of them. I checked console doing like Posts.find({}).count() and surprisingly it's having every post.
So my question is should I add query to find even after I subscribe the proper publish function? Or am I wrong at some point?

Answer 1

Whenever you start a subscription in Meteor you are adding those subscribed collections to a local collection. So if you have a boards collection and in your home page you subscribe to see ALL collections like:
$meteor.subscribe('getAllBoards')
You are adding ALL of the boards to the local collection. This local collection will be persistent until you explicitly stop the subscription. So in your board details page you still have access to that full collection.
If you notice you are using 2 different methods for subscribing. $scope.$meteorSubscribe and $meteor.subscribe. The first one will automatically remove the subscription when the $scope is destroyed. The second one will keep it.
So, if you wanted to remove the collection and re-subscribe when entering the board details page, you would want to use $scope.$meteorSubscribe in your main page as well.
Here's some food for thought. If you are on your main page and you use $meteor.subscribe, then you already have that information for those posts locally, correct? So, when you click on a link to view the board details, you don't actually need to subscribe again. You can just call:
$scope.board = $meteor.object(Boards, symbol: boardSymbol, false);
And you'll have access to that boards information. ( I just realized you were talking about Posts and not Boards, but the idea is still the same).
Short Answer: $meteor.subscribe() does not cancel the subscription on it's own, you have to tell it to. $scope.$meteorSubscribe does cancel the subscription.
Best practice? I would set the options for the subscription and then just create a local collection using find() like:
$scope.$meteorSubscribe('getPopularPosts', _.defaults(DEFAULT_QUERY_OPTIONS, limit: 5).then(-> {
$scope.posts = $scope.$meteorCollection(->
Posts.find();
)
})
Then in your publish add in the options:
Meteor.publish('getPopularPosts', function(options) {
return Posts.find({}, options);
});
This would limit the number of posts sent to the client rather than sending all of them and the only using 5.
When you switch to the board details view it will no longer have this information available to trip you up, because we used $scope.$meteorSubscribe and $scope.$meteorCollection.