How can I access value from pointer inside pointer on query with Parse in swift?
This has to do with three classes in Parse. One is called Post_Story, on is Post and one is User. When I query for Post_Story i am able to retreive pointer info from a key "Post", but is there any way to access information from a pointer within that pointer? (key "createdBy" to User class)
My code looks like this:
let postQuery = PFQuery(className: "Post_Story")
postQuery.whereKey("story", containedIn: storyObjects)
postQuery.includeKey("post")
postQuery.findObjectsInBackgroundWithBlock { (objects:[PFObject]?, error:NSError?) in
if error == nil {
for object in objects! {
if let postL = object["post"] as? PFObject {
if postL["createdBy"] != nil {
//this is where I want to get infor from PFUser, but not all info is sent
print((postL["createdBy"] as! PFUser)) //prints PFUser object without username etc.
}
}
}
}
else {}
}
I hope the question is not too stupid...
You can add postQuery.includeKey("post.createdBy") to include the user object in the createdBy column of post.
Related
I am working on an app where the user is connected (in) multiple school classes. Since a student will be in more than one class, am I able to set an array of pointers to an individual user or is that not possible (maybe a relation is better)?
Here is my code:
let classPointerQuery = PFQuery(className: "Classes")
classPointerQuery.whereKey("class_name", equalTo: self.classNameTextField.text!)
let classQuery = PFQuery.orQueryWithSubqueries([classPointerQuery])
classQuery.findObjectsInBackgroundWithBlock({ (results: [PFObject]?, error: NSError?) -> Void in
if let objects = results {
for object in objects {
let userInfo = PFUser.currentUser()!
userInfo["my_classes"] = object
userInfo.saveInBackgroundWithBlock({ (success: Bool, error: NSError?) -> Void in
if error != nil {
spinningActivity.hideAnimated(true)
self.displayAlert("Error", message: error!.localizedDescription)
} else if success {
spinningActivity.hideAnimated(true)
self.dismissViewControllerAnimated(true, completion: nil)
} else {
spinningActivity.hideAnimated(true)
self.displayAlert("Something Went Wrong", message: "Please try again")
}
})
}
}
})
* Note: I also tried changing - userInfo["my_classes"] = object - to - userInfo["my_classes"] = [object] - and got an error, "invalid type for key my_classes, expected *Classes, but got array (Code: 111, Version: 1.12.0)"
What I am doing here is querying for the object of the class that I want - lets say the user wants to add the class "Physics" - the query queries for the "class_name" in the Parse class "Classes" and spits out the object. This object is then set the current user's "my_classes" -> a pointer object. I there a way, when the user wants to add "Calculus" that the pointer object in Parse will have 2 pointers instead of replacing the current pointer?
Thanks in advance for the help!
you cant store Pointers in array, you can store objectID in the array as string and do the query like that.... the general rule is that u use Pointers for 1:many relationships in database and Relations in many:many...
Update 1 - Saving objectID to Array in Parse
PFUser.currentUser()!.addObject(somePFObject.objectID!, forKey: "my_classes")
for queries you will than use containedIn
querySetup.whereKey("class", containedIn: array)
I have a tableView with a CollectionView inside, in the TableView is the users details and I am trying to put the images belonging to the user in the collectionView.
So far I have everything working correctly apart from the images are not correct. Every image uploaded is displaying for each user, I need match the images to the user...I have been trying for a while now and have not found a solution so I'm hoping someone can help me here!
Here is my query for getting the user details and images:
func loadPosts() {
let followQuery = PFQuery(className: "Follows")
followQuery.whereKey("follower", equalTo: PFUser.currentUser()!.username!)
followQuery.findObjectsInBackgroundWithBlock ({ (objects:[PFObject]?, error:NSError?) -> Void in
if error == nil {
self.followArray.removeAll(keepCapacity: false)
for object in objects! {
self.followArray.append(object.valueForKey("following") as! String)
}
self.followArray.append(PFUser.currentUser()!.username!)
let query = PFQuery(className: "Posts")
query.whereKey("usernamee", containedIn: self.followArray)
query.addDescendingOrder("createdAt")
query.findObjectsInBackgroundWithBlock({ (objects:[PFObject]?, error:NSError?) -> Void in
if error == nil {
self.usernameArray.removeAll(keepCapacity: false)
self.imageArray.removeAll(keepCapacity: false)
self.uuidArray.removeAll(keepCapacity: false)
for object in objects! {
self.usernameArray.append(object.valueForKey("username") as! String)
self.imageArray.append(object.valueForKey("imageArray") as! PFFile)
self.uuidArray.append(object.valueForKey("uuid") as! String)
}
self.tableView.reloadData()
} else {
print(error!.localizedDescription)
}
})
} else {
print(error!.localizedDescription)
}
})
}
Best regards.
There are three issues I see in your code. First of all, in your Posts query, you use the whereKey() method: query.whereKey("usernamee", containedIn: self.followArray). username is spelled incorrectly, and this may be causing some issues. In addition, you remove all objects from your array every time you issue a query. There must be some way to add and remove data as necessary. (This only applies if you are refreshing data. If you have not added data to the arrays, there is no need to empty them.) Finally, you have a value called imageArray that is stored as a PFFile. An array would be multiple objects. It is hard to tell whether or not each user has multiple images or not. (For the solution, I assume that there is only one image per user. I would suggest changing the name of the key to be more precise. If this is not the case, write me a comment.)
Now, in regards to your actual problem, I believe that this is because you have only one array for all the images, and when you display it for each user, the entire array is used. In order to correct for this, I would suggest building a data structure in the following format: [(String, Image)], where String is the username and Image is file for the image. You can thus access the users and their images as an array of tuples.
To create the array of tuples, I would suggest: var usersAndImagesArray = [(username: String, imageFile: PFFile)]()
To add to the array:
for object in objects!{
usersAndImagesArray.append(object.valueForKey("username") as! String, object.valueForKey("image") as! PFFile)
}
To access the values when setting up the cells:
let username = usersAndImagesArray[index.row].username
let imageFile = usersAndImagesArray[index.row].imageFile
I am trying to do a multiple PFQuery and storing the data properly.
My plan is to query for group members in my Group
I am looking for the key member. It gives me an array of objectIds. Then I want to query in my _User class for their picture with key firstImage. Displaying the data is not the problem, just getting it the right way.
The data needs to be stored considering it's groups. This is what i tried so far:
let fetchGroupsQuery = PFQuery(className: "Group")
fetchGroupsQuery.whereKey("member", equalTo: objectID!)
fetchGroupsQuery.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
if error != nil
{
}
else {
if let objects = objects {
self.memberPhotos.removeAll()
for object in objects {
if let member = object["member"] as? [String]
{
// returns array of objectIds
for user in member
{
// returns single ids
self.groupIds.append(user)
let photoQuery = PFUser.query()
photoQuery?.whereKey("objectId", equalTo: user)
photoQuery?.findObjectsInBackgroundWithBlock({ (results, error) -> Void in
if error != nil {
// ....
}
else {
self.memberPhotos.removeAll()
if let results = results
{
for result in results
{
if result["firstImage"] != nil
{
self.memberPhotos.append(result["firstImage"])
}
}
}
}})
}
}
My idea was to store the data within an array of arrays.
So that I can later go into array[indexPath.row] to get the array I need to loop through in order to get the right group pictures.
Any ideas how to solve this?
I would use two separate queries function:
1) to get their ID's
2) for their pictures.
For the first query: what you need to change?
Your objectID array should be of type of NSMutableArray because in order to fetch their info you should use the constraint whereKey containedIn not whereKey equalTo
and for that constraint you should downcast your NSMutableArray to type AnyObject.
Also change the Type of your groupIds to NSMutableArray, then append your array.
For the Second query:
Since your groupIds Type is already NSMutableArray just cast it to AnyObject,then use the whereKey containedIn
Note: It would be better to download all images before appending your
array. So you have the option of using struct or class(easier to
group data to its owner) then create an array of that data
structure.Where it because easier to populate your UI.
I've attempted to solve this error, but I've had no luck in doing so. I'm getting the error: Cannot subscript a value of type '[PFObject]' with an index of type 'String' On this line of code: self.postDates.append(posts["createdAt"] as! String).
This is the portion of code I'm having trouble with:
var posts : [Post] = []
var postDates = [String]()
func loadData() {
var query = PFQuery(className: "Post")
query.orderByDescending("createdAt")
query.findObjectsInBackgroundWithBlock {(posts: [PFObject]?, error: NSError?)-> Void in
if error == nil {
if let posts = posts {
for post in posts {
self.postDates.append(posts["createdAt"] as! String)
}
self.tableView.reloadData()
}
} else {
// is an error
}
}
}
I'm trying to get the date and then display it every time the user create a new post utilizing Parse. Can anyone explain what is going on?
This is the tutorial I'm following along with: https://www.youtube.com/watch?v=L3VQ0TE_fjU
Because posts is an array of PFObject, how can you get an element inside from String? It's supposed to be an Int. It's just your typo, you already knew what you are doing. post is the PFObject you want.
for post in posts {
self.postDates.append(post["createdAt"] as! String)
}
You are trying to get (and add) the created at date of the PFObject,
instead you are getting the date of and array of PFObject (Which Posts is).
You should try to get the elements in the array, and get the date from the element instead of the array.
for post in posts{
postDates.append(post["createdAt"] as! String)
}
I am very new to swift and I don't know Obj C at all so many of the resources are hard to understand. Basically I'm trying to populate the dictionary with PFUsers from my query and then set PFUser["friends"] to this dictionary. Simply put I want a friends list in my PFUser class, where each friend is a PFUser and a string.
Thanks!
var user = PFUser()
var friendsPFUser:[PFUser] = []
var friendListDict: [PFUser:String] = Dictionary()
var query = PFUser.query()
query!.findObjectsInBackgroundWithBlock {
(users: [AnyObject]?, error: NSError?) -> Void in
if error == nil {
// The find succeeded.
println("Successfully retrieved \(users!.count) users.")
// Do something with the found objects
if let users = users as? [PFUser] {
friendsPFUser = users
for user in friendsPFUser{
friendListDict[user] = "confirmed"
}
user["friends"] = friendListDict //this line breaks things
user.saveInBackground()
}
} else {
// Log details of the failure
println("Error: \(error!) \(error!.userInfo!)")
}
}
To be clear, this code compiles but when I add
user["friends"] = friendListDict
my app crashes.
For those who might have this issues with. "NSInternalInconsistencyException" with reason "PFObject contains container item that isn't cached."
Adding Objects to a user (such as arrays or dictionaries) for security reasons on Parse, the user for such field that will be modified must be the current user.
Try signing up and using addObject inside the block and don't forget do save it!
It helped for a similar problem I had.