How to publish posts depend on privacy? - mongodb

Question

I need to publish a queue from collection Posts depending of privacy. But I don't have any idea how to get this. I've draw mindmap of main concept what I try to realize:
Input:
var currentUser = "Andrey";
Events.find();
Output:
[
{
//it's going to output, becouse I've created this post
"_id" : "1",
"createdBy" : "Andrey",
"private" : true,
"title" : "",
"text": "",
"members" : [
"Sheldon", "Mike"
]
},
{
//it's going to output, becouse this post not private
"_id" : "2",
"createdBy" : "Sheldon",
"private" : false,
"title" : "",
"members" : []
},
{
//it's going to output, becouse I'm one of members'
"_id" : "3",
"createdBy" : "Mike",
"private" : true,
"title" : "",
"text": "",
"members" : [
"Andrey"
]
},
{
//it's NOT going to output, becouse it's private post, I'm not the member or author
"_id" : "4",
"createdBy" : "Ana",
"private" : true,
"title" : "",
"text": "",
"members" : [
"Sheldon"
]
},
]
Expected result:
[
{
"_id" : "1",
"createdBy" : "Andrey",
"private" : true,
"title" : "",
"text": "",
"members" : [
"Sheldon", "Mike"
]
},
{
"_id" : "2",
"createdBy" : "Sheldon",
"private" : false,
"title" : "",
"text": "",
"members" : []
},
{
"_id" : "3",
"createdBy" : "Mike",
"private" : true,
"title" : "",
"text": "",
"members" : [
"Andrey"
]
}
]
But this idea can be wrong at all, maybe you have another way?

Answer 1

I am not sure if this is the right approach but probably I'd try something like that if I face this issue. (By the way I'd use userId instead of names. If you used names in order to explain your aim, please ignore this comment)
As long as I remember, you can return multiple query results like that
return [
Result1,
Result2,
]
For the public posts, no need to worry I guess. Just returning the ones with private: false is sufficient.
For the private ones, I'd use userId as parameter and try this composite publication:
Meteor.publish('posts', function postPublication(userId) {
return [
Posts.find({
$and: [{
$or: [
{_id: userId},
{memberId: {$in: userId}}
]},
{private: {$eq: true}}
]}), // => should return private posts created or commented by member
Posts.find({private: {$eq: false}}) // => should return public ones
];
}
Then do the subscription with userId
Meteor.subscribe('posts', userId);

Answer 2

This code how I solved this task, with $or $and. But not sure too, if it's a best solution. But I get expected result.
Meteor.publish('posts', function(currentUser) {
selector = {
$or : [
{ $and : [ {'private': true, 'members': currentUser} ] },
{ $and : [ {'private': true, 'author': currentUser} ] },
{ $and : [ {'private': false, 'author': currentUser} ] },
{ $and : [ {'private': undefined} ] },
{ $and : [ {'private': false} ] },
]
}
return Posts.find(selector);
});