Swift - load from Parse table based on array values - ios

Question

I have the following flow in my app:
User selects to view his contacts list
I go and load from the FriendsConnection table the array of friends (usernames) that match the current user logged (basically friends of current user). Store in array
Another database query to the Users class in Parse to get the information of related to each username in the array stored locally. Store this locally
Populate Table View with contact list and once clicked show details.
For step 2 above, I have:
var friendsUsernamesListArray: [String] = []
func loadFriendsUsernames()
{
let query = PFQuery(className:"FriendsConnections")
query.whereKey("appUsername", equalTo:PFUser.currentUser()!["appUsername"])
query.findObjectsInBackgroundWithBlock {
(objects: [PFObject]?, error: NSError?) -> Void in
if error == nil{
//print("Successful")
//print(objects)
self.friendsUsernamesListArray = objects![0]["friendsList"] as! NSArray as! [String]
}else{
print("Failure")
}
}
}
and now the values of friendsUsernamesListArray are:
["username1", "username2", "username3"]
I am not sure how to do the third part to get one major object in return with one request (to avoid a single request for each username in the array above). What I want is probably to get something like this:
User1 -> [name: XXXXX, age: 20, number:019282992] User2 -> [name:
YYYY, age: 22, number:045527229]
Thanks for your help in advance

Answer 1

Found the answer and sharing it for future reference for similar issues:
The solution is to use containedIn keyword as provided by Parse PFQuery.
func loadFriendsInfo()
{
let query : PFQuery = PFUser.query()!
query.whereKey("appUsername", containedIn: self.friendsUsernamesListArray)
query.findObjectsInBackgroundWithBlock {
(objects: [PFObject]?, error: NSError?) -> Void in
if error == nil{
print(objects)
}else{
print("Getting Usernames Info Failure")
print(error)
}
}
}
The above code works and happy to answer any questions related to it.

Answer 2

You could also try this (slightly similar to the previous answer)
let query = PFQuery(className: "Users")
query.findObjectsInBackgroundWithBlock{(objects, error) -> Void in
if objects.count > 0 {
for object in objects {
for friend in self.friendsUsernamesListArray {
if object["username"] == friend {
//get objects info and add it to other things. E. g. object["email"]
}
}
}
}
}
Let me know if this works. You may need to add some question/ exclamation marks for optionals. Hope this helps.