SmartQuery

Getting rid of publish() and subscribe()

SmartQuery takes your regular Collection.find() calls, and wraps them in a special function that automatically sets up the subscription you need for you.

Demo

Using SmartQuery (Client)

Just call SmartQuery.create() inside a regular template helper. For example:

1Template.posts.helpers({
2  posts: function () {
3    var cursor = Posts.find({}, {limit: Session.get("postsLimit")});
4    return SmartQuery.create("posts", cursor);
5  }
6}

SmartQuery.create(id, cursor, options)

id: a unique id for this particular SmartQuery.
cursor: the cursor you want to use (e.g. Posts.find({}, {limit: 5})).
options: an optional options object.

Returns an object with the following properties:

subscription: the subscription created for this SmartQuery.
cursor: the cursor you passed to the SmartQuery.
isReady(): (function) whether the subscription is ready (Boolean).
count(): (function) returns a count of the cursor.
totalCount(): (function) returns the total count for the cursor on the server (without a limit).
hasMore(): (function) whether there are more documents on the server (Boolean).

Defining A Security Layer (Server)

You must define a security rule on the server for each collection before data can be published to users.

SmartQuery.addRule(collection, rule)

collection: the collection.
rule: the rule.

A rule has the following properties:

filter(document): a function that, if provided, must return true for every single document in the cursor. Inside the filter function, you can call this.userId to access the current user's _id.
fields(): a function that, if provided, must return an array of publishable fields. If no fields function is provided, all fields will be published.

In both the filter and fields function, you can access the current user _id with this.userId.

Example:

1SmartQuery.addRule(Posts, {
2  filter: function (document) {
3    return document.published === true;
4  },
5  fields: function () {
6    return ["_id", "title", "body"];
7  }
8});

Using SubsManager

You can also use SmartQuery with SubsManager:

1var mySub = new SubsManager();
2var options = {
3  subscribe: mySub.subscribe.bind(mySub)
4};
5SmartQuery.create("the-id", Posts.find(), options);