Determine the presence of a value within an array in mongodb

Question

Determine the presence of a value within an array in mongodb

How can I determine if the current Meteor.user()._id exists in the "favoritedBy" array?

If true, display "Your favorite", if false, display "Not your favorite".

Here is an example document in MongoDB:

{
  "_id" : "W5WwAZatorDEb6DNP",
  "createdBy" : "aTmb64zNGSyeDYFJZ",
  "favoritedBy" : [ 
      "X594baqWYZiJqA3Qg",
      "fgk234m2dkD229d12"
  ]
}

Assume that Meteor.user()._id returns X594baqWYZiJqA3Qg.

How can I perform a true/false check on this?

I attempted the following code:

isFavorite: function() {
    var user = Meteor.user()._id;
    return Posts.find({favoritedBy: user});
 }

In the template:

{{#if isFavorite}}
    Your favorite
{{else}}
    Not your favorite
{{/if}}

However, the code does not seem to work properly, as it always displays "Your favorite", even when the current Meteor user id is not in the array.

Any suggestions?

javascript arrays mongodb meteor mongodb-query

Answer 1

Answer №1

One way to determine if a user has favorited something is by using the following JavaScript function:

isFavorite: function() {
    var user = Meteor.user()._id;
    return Posts.find({favoritedBy: user}).count() > 0 ? true : false;
 }

The count() method in this function will return the number of documents that match a specific query. By checking if this count is greater than zero, the function uses a ternary operator to return either true or false based on the result.

Answer 2

One way to determine if a user has favorited something is by using the following JavaScript function:

isFavorite: function() {
    var user = Meteor.user()._id;
    return Posts.find({favoritedBy: user}).count() > 0 ? true : false;
 }

The count() method in this function will return the number of documents that match a specific query. By checking if this count is greater than zero, the function uses a ternary operator to return either true or false based on the result.

Determine the presence of a value within an array in mongodb

Answer №1

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