I have made a QR scanner App, I have manually put some QR codes into parse for it to recognise, any QR codes scanned that I haven't put into parse don't get recognised.
The only thing to tell them apart is their (Info) i.e "restaurant", "nail salon" etc.
I am after a way to be able to record an Integer of how many times the chosen QRCode has been scanned, to then place on a label in the app.
I can (.count) ALL of the qrCodes saved and scanned by the user but can't seem to figure out how I can then either put all "Nail Salons" into their own array on parse or run a For loop matching the ones I need.
// The code below will retrieve everything in the "info" column and print it to console
// This prints "Nails Salon" x 5, "Restaurant" x3 and "Coffee Shop" x 7 in the order that they were scanned (Unorganised)
// What block of code could I make to display what PFuser.current currently has in their parse?
// E.g. PFUser has scanned "Nail Salon" 5 Times, "Restaurant" 3 time etc etc
let infoCheck = PFQuery(className: "UserQRCodes")
infoCheck.whereKey("info", contains: "")
infoCheck.findObjectsInBackground { (objects: [PFObject]?, error: Error?) in
if let error = error {
print(error.localizedDescription)
} else if let objects = objects {
print(objects)
}
}
// To retrieve everything the USER has scanned and display it as String on the APP
let query = PFQuery(className: "UserQRCodes")
query.whereKey("userName", equalTo: PFUser.current()!)
query.findObjectsInBackground { (objects: [PFObject]?, error: Error?) in
if let error = error {
//log details of the failure
print(error.localizedDescription)
} else if let objects = objects {
let stampees: Int = objects.count
let totalStampees = String(stampees)
self.stampeesCollectedLabel.text = totalStampees
print(objects.count)
}
}
// Do any additional setup after loading the view.
}
You want to filter elements in your array of scans. For each code type, call something like
// '$0' is your PFObject. Replace 'name' with whatever `PFObject` property
// represents the object's type
let nailSalons = objects.filter { $0.name == "Nail Salon" }
You can then use this filtered array to get your count.
Note that the filter { $0... } syntax is a shorthand for
objects.filter { (object) throws -> Bool) in
return object.name == "Nail Salon"
}
You'll need to use the full version if your condition is anything more complicated than a simple one-line expression. Note that in the short version, the return is implied.
Related
I'm trying to develop an app that provide User sign up and within the UI I want to query if the email is exists or not.
The problem is since I change from swift 2 to swift 3 I got these errors
var query = PFObject(className:"User")
query.whereKey("email", equalTo: email)
query.findObjectsInBackground {
(objects, error) -> Void in
if error == nil {
// The find succeeded.
print("Successfully retrieved \(objects!.count) scores.")
// Do something with the found objects
if let objects = objects {
for object in objects {
print(object.objectId)
}
}
} else {
// Log details of the failure
print("Error: \(error!) \(error!.userInfo)")
}
}
/Users/**************/SignUpSenderViewController.swift:49:9:
Value of type 'PFObject' has no member 'whereKey'
/Users/i*************/SignUpSenderViewController.swift:50:9:
Value of type 'PFObject' has no member 'findObjectsInBackground'
any suggestion to solve this challenge ?
I dont know what documentation you checked but the query has to be done this way...
let query = PFQuery(className:"_User")
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 use parse to query current user's friend list and the friend request user and when user press each cell of the friend request, The app will add that friend back and delete the selected friend request so I query friend list and friend request and use "addedArray" as friend requests and "duplicate" as array of current user's friend list and use for loop to find the duplicate of friend list and friend request and delete that friend from addedArray so the current user will se the latest friend requests
Here's my code in swift
func queryAdded(){
let query = PFQuery(className: "Request")
let user = PFUser.currentUser()?.relationForKey("Friends")
let query2 = user?.query()
query.whereKey("To", equalTo: PFUser.currentUser()!)
query.findObjectsInBackgroundWithBlock {
(objects, error) -> Void in
if error == nil{
for object in objects! {
print("query")
let username = object.valueForKey("FromUsername") as! String
self.userCellAdded = username
self.addedArray.append(username)
print(username)
print(self.addedArray.count)
}
print("READY")
print(self.addedArray.count)
self.tableView.reloadData()
}
else{
/* dispatch_async(dispatch_get_main_queue()){
//reload the table view
query.cachePolicy = PFCachePolicy.NetworkElseCache
}*/
print("errorrrr")
}
}
query2!.findObjectsInBackgroundWithBlock{(objects,error) -> Void in
if error == nil {
for object in (objects)!{
if let username = object["username"] as? String {
self.duplicate.append(username)
print("duplicate")
print(username)
print("size")
print(self.duplicate.count)
}
}
}
}
for self.iIndex = 0 ; self.iIndex < self.addedArray.count ; ++self.iIndex {
for self.jIndex = 0 ; self.jIndex < self.duplicate.count ; ++self.jIndex {
print("in for loop")
if self.addedArray[self.iIndex] == self.duplicate[self.jIndex] {
self.addedArray.removeAtIndex(self.iIndex)
self.tableView.reloadData()
print("find")
}
}
}
}
The problem is The method queryAdded() does not run for loop for me and I don't understand why
The duplicate array and the addedArray have value and size but still it didn't go inside the for loop
Your problem is that your for loop is depending on the results of two asynchronous operations. What happens is that your app starts these two background queries and then immediately starts the for loop. Since there is no data yet from the queries, the for loop has no data to work on.
You can either solve this by creating a "pyramid hell" by nesting your operations (bad), or you can use a framework to achieve the same as Promises would provide for JavaScript (good).
Since you're using Parse, you have such a framework already; namely the Bolts Framework. You could then perform these operations sequentially using tasks (BFTask).
Example from the Bolts readme:
var query = PFQuery(className:"Student")
query.orderByDescending("gpa")
findAsync(query).continueWithSuccessBlock {
(task: BFTask!) -> BFTask in
let students = task.result() as NSArray
var valedictorian = students.objectAtIndex(0) as PFObject
valedictorian["valedictorian"] = true
return self.saveAsync(valedictorian)
}.continueWithSuccessBlock {
(task: BFTask!) -> BFTask in
var valedictorian = task.result() as PFObject
return self.findAsync(query)
}.continueWithSuccessBlock {
(task: BFTask!) -> BFTask in
let students = task.result() as NSArray
var salutatorian = students.objectAtIndex(1) as PFObject
salutatorian["salutatorian"] = true
return self.saveAsync(salutatorian)
}.continueWithSuccessBlock {
(task: BFTask!) -> AnyObject! in
// Everything is done!
return nil
}
You could then first prepare both your queries and then start the chain of tasks:
query1.findObjectsInBackground().continueWithSuccessBlock {
(task: BFTask!) -> BFTask in
var objects = task.result() as NSArray
for object in objects {
//collect your usernames
}
return query2.findObjectsInBackground()
}.continueWithSuccessBlock {
(task: BFTask!) -> AnyObject! in
var objects = task.result() as NSArray
for object in objects {
// collect your usernames from relation
}
// Call a function containing the for loop that is currently not running
return nil
}
The for loop is run
duplicate array and the addedArray have value and size - No they don't
findObjectsInBackgroundWithBlock runs the query in ... the background.
Therefore your program does the following:
start the first query
start the second query
run the for loop
the queries finish at some arbitrary point in time.
In particular when the program reaches point 3 the arrays do not contain anything, they are empty arrays, therefore the for-loop executes perfectly fine as it is supposed to be: it does nothing since there is nothing to loop over.
Solution:
Move the for loop into a function that you call after the first query and the second query finish.
I have an app that I need to grab all values in the class. I need to get "players" and "total" from the class "runningTotal". Here is the code I have:
var query = PFQuery(className:"runningTotal")
query.selectKeys(["players", "total"])
query.findObjectsInBackgroundWithBlock
{
(objects: [AnyObject]!, error: NSError!) -> Void in
if error == nil
{
self.test = objects[0]["total"]
}
}
I want to set a variable (test) equal to the result of total. I would also want to do this with players. I don't think the above code is right, as it doesn't work. I obviously don't need any constraints as I want to fetch all of the results from this class. How would I go about solving this?
Thanks for any help in advance!
As long as your query is error free, you'll need to iterate through the objects array. As you iterate through each object, which will be of type AnyObject, you will need to cast the object as a PFObject. Then you will be able to grab the data you require from it.
var query = PFQuery(className:"runningTotal")
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]!, error: NSError!) -> Void in
if error == nil{
for object in objects{
if let data = object as! PFObject{
//Set test to total (assuming self.test is Int)
self.test = data["total"] as! Int
}
}
}else{
//Handle error
}
}
All I am trying to get multiple objects out of a parse database.
Here is some of my code :
So this does the query :
var MainPicture = PFQuery(className: "Staff")
MainPicture.whereKey("Position", equalTo: "Sales Manager")
MainPicture.findObjectsInBackgroundWithBlock ({(objects:[AnyObject]!, error: NSError!) in
if(error == nil){
self.getMainImageData(objects as [PFObject])
}
else{
println("Error in retrieving \(error)")
}
Then I want to get a few rows out of the query :
func getMainImageData(objects: [PFObject]) {
for object in objects {
let MainPic = object["StaffPic"] as PFFile
let MainData = object["FirstName","SecondName","Position"] as PFFile
MainPic let works, but when I try and do multiple ones like MainData , I get an error : "Extra argument in call" .. I thought this would have worked.
I suspect you cannot subscript PFObject with multiple items. It is like calling
dictionary["key1", "key2"]
That will also result in too many arguments.
It is confusing that your variables are Capitalized. They look like class names.