I have an array column in Parse that is called homeAddress. Inside it is the following value for a single row:
["111111","222222"]
I wish to access this in swift. I created a local array called homeAddress of String type. How can I store the first element in the Parse column (i.e. 111111) in the first element holder in local array i.e. homeAddress[0]? And then I need to store the 222222 in the homeAddress[1].
So what you want is load this data from parse. You can just call a Parse Query get the results and work with them:
let query = PFQuery(className:"ClassName")
query.findObjectsInBackgroundWithBlock {
(results, error) -> Void in
if (error == nil) {
for object in results!{
let homeAddress = object["homeAddress"] as! NSArray
}
}else {
print(error?.userInfo)
}
}
One way would be to trim first and last character and just separate values by comma:
var test = "[\("111111"),\("222222")]"
var trimmedStringRange = Range<String.Index>(start: test.startIndex.successor(), end: test.endIndex.predecessor())
var homeAddress = test.substringWithRange(trimmedStringRange).componentsSeparatedByString(",")
If your local array is empty, you can add your values from the parse array like this (after getting the array from Parse):
localHomeAddress.append(homeAddress)
This will put all values from homeAddress array in localHomeAddress array.
If you use a splice, you can ensure you are adding the values from index 0:
localHomeAddress.insertContentsOf(homeAddress, at:0)
Related
I have a dictionary var items = [String:String]()
Then I assign values :
for i in itemInCart {
items["param_id"] = i.modelId
//items["param_id"]?.append(i.modelId!)
}
print(items)
I have just a last value.
I know that the method append() is not applicable to dictionaries, but how can I fill it then?
This is because you are replacing param_id every time for loop i so it will always a last element you will found
You have two options, either create a unique key for each element (a bad idea) or if you want all the elements you have to create array and add it into the param_id key like:
items["param_id"] = itemInCart.map { $0.modelId }
so now your dictionary is [String:Any]() or [String:[String]]()
I am currently having a big issue sorting my Data alphabetically in a 2D array. I'm going to try to give you every detail to be as clear as possible.
Currently, I am fetching my contacts with the CNContactStore. This all works fine. I am able to retrieve all the data I want out of my contacts.
Now, I created the following struct:
struct FavoritableContact {
let contact: CNContact
var hasFavorited: Bool
}
With this, I declared and initialized the following array:
var favoritableContacts = [FavoritableContact]()
Once I retrieved my contacts, I simply appended them to favoritableContacts;
try store.enumerateContacts(with: request, usingBlock: { (contact, stopPointerIfYouWantToStopEnumerating) in
favoritableContacts.append(FavoritableContact(contact: contact, hasFavorited: false))
})
To sort them in alphabetical order in the same array, I simply did the following:
var sortedContacts = favoritableContacts.sorted { $0.contact.familyName < $1.contact.familyName }
Now if possible, I want to create the following 2D array,
var 2D = [
[FavoritableContact] //"A"
[FavoritableContact], //"B"
[FavoritableContact], //"C"
[FavoritableContact], //"D"
...
]
I am just not sure how to take my sortedContacts array and separate alphabetically.
I am very new here, If I forgot something, or I didn't do somethign right please let me know.
As was pointed out in the comments, a dictionary with first letters as keys is probably the better way to go as it is much easier to access, though perhaps you have a reason for wanting to use a 2d array instead. To achieve that you could do something like this:
//Create an empty array filled with 26 arrays of FavorableContact
var array2d = Array<[FavoritableContact]>(repeating: [FavoritableContact](), count: 26)
//Find the ascii value for "A" to use as your base
let aAscii = Int("A".unicodeScalars.filter({ $0.isASCII }).map({ $0.value })[0]) //This returns 65, btw, so you could also just hardcode
//Go through your original array, find the first letter of each contact, and append to the correct array
favoritableContacts.forEach { (contact) in
//Get the ascii value for the first letter
let firstLetter = Int(contact.contact.familyName.prefix(1).uppercased().unicodeScalars.filter({ $0.isASCII }).map({ $0.value })[0])
//Append to the array for this letter by subtracting the ascii value for "A" from the ascii value for the uppercased version of this letter.
array2d[firstLetter - aAscii].append(contact)
}
This is not the cleanest thing in the world, and it assumes standard English language alphabet with no diacritics, symbols, numbers or anything else. Assuming that is true it gets the job done.
Could use something like this.
var contactsLeftToSort : [FavoritableContact] = []
var doubleArray : [[FavoritableContact]?] = [[FavoritableContact]?]()
var index : Int = 0
for char in "ABCDEFGHIJKLMNOPQRSTUV" {
doubleArray.append(nil)
var i = 0
while i < contactsLeftToSort.count {
let contact = contactsLeftToSort[i]
if contact.name.first == char {
doubleArray[index] == nil ? doubleArray[index] = [contact] : doubleArray[index]!.append(contact)
contactsLeftToSort.remove(at: i)
}
//assuming original list is alphabetized.. if not, delete this line.
if contact.name.first! > char { break }
i += 1
}
index += 1
}
As I wrote in the comments above, I think you can achieve this in a much more elegant way by using a dictionary instead of an array.
SWIFT 4
let sortedContacts: [FavoritableContact] = ... // An array of FavoritableContact objects, they should be sorted
let groupedContacts = Dictionary(grouping: contacts, by { $0.familyName.first! })
You now have a dictionary of all your contacts where the keys are the alphabetical letters (ie. A-Z) and the values are arrays of sorted FavoritableContact objects (assuming you sorted the big array of FavoritableContacts before creating the dictionary).
If you wanted to use this as the datasource for your tableview, you would make the number of sections all the possible first letters of family names. For the number of rows in each section, you return the count of the array for the key like so:
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
let letterForSection = letterForSection() // Custom method to get the section of the letter
return contactsDict[letterForSection].count
}
The rest of the datasource methods would work in a similar way.
Man, all of these answers are really over-complicating this. All you need is something along the lines of:
let groupedContacts = Dictionary(grouping: contacts, by: { $0.contact.firstName.first! })
for initial, contacts in groupedContacts.lazy.sorted().{ $0.key < $1.key} {
print("#################", initial)
contacts.forEach{ print($0) }
}
I have passed a dictionary to a second view controller and assigned it to an array, I thought I could access the data easier this way:
var myAlerts: NSDictionary!
The dictionary has three elements for each: Id (which I don't care about), alertDate, and alertNote.
I'm trying to get these elements into a tableView but struggling with this.
I thought about just moving it into two arrays and accessing it that way, cumbersome but it at least gets me further down the road so to speak.
Here is the raw data from the dictionary AFTER it was past to the second controller:
{
alerts = (
{
alertDate = "2017-07-16";
alertNote = "Rob is the worlds greatest friend";
id = 2;
},
{
alertDate = "2017-07-17";
alertNote = "This is a test of the emergency system";
id = 1;
}
);
}
When I tried to move the values into two arrays with this:
func CreateArray() {
for i in 0...myAlerts.count {
alertsDate[i] = myAlerts["alerts"]["alertDate"]
alertsNote[i] = myAlerts["alerts"]["alertNote"]
}
}
I get the proverbial Type Any? has no subscript members.
Any help would be appreciated.
myAlerts with that data is now a dictionary containing an array of dictionaries. (so top level is a dictionary, with one key/value pair which is of type array of [String:Any] objects).
Since a dictionary value is of type Any, it can't infer in this case what the type of the value for the key alerts is. So you have to try cast it to a specific type first, in this case an array of dictionaries, i.e. [[String:Any]]
So this should get rid of your error:
func CreateArray() {
for i in 0...myAlerts.count {
let alertArray = myAlerts["alerts"] as! [[String:Any]]
alertsDate.append(alertArray[i]["alertDate"] as! String)
alertsNote.append(alertArray[i]["alertNote"] as! String)
}
}
Note: I had to change alertsDate and alertsNote arrays to using append as in my demo code i had no existing items in the array and using and index would have caused an error.
When the user searches for a category I need all the arrays that contain that same category to appear + the other categories that are in that respective array.
Once the user has chosen ["Apples", "Oranges", "Limes"] I want to compare which array (out of many) that I queried contains Apples, Oranges or Limes. This can be one array or this can be many arrays.
These are the arrays I'm adding the values to:
var categoryNeeded = [AnyObject]() //The user creates this one and adds values to it
var categoryArr = [AnyObject]() //The Parse arrays are added here:
I have a simple Parse query function.
var query : PFQuery = PFUser.query()!
query.whereKey("contacts", containsString: "\(categoryArr)")
query.findObjectsInBackgroundWithBlock { (objects, error) -> Void in
if let objects = objects as [PFObject]! {
for object in objects {
self.categoryArr.append(object["contacts"] as! AnyObject)
print(self.categoryArr)
}
}
}
The 2nd line is suspect:
query.whereKey("contacts", containsString: "\(categoryArr)")
When querying with that line, I get this error (without a crash):
2016-01-23 15:53:47.508 CC[28514:5733236] [Error]: $regex only works
on string fields (Code: 102, Version: 1.11.0)
Without the whereKey line, I get all the values and it prints them. I just can't figure out how to compare and check for matches between the two arrays which ultimately gives the matching arrays. Is there a Swift method that does that?
You should not use containsString but rather containedIn:
query.whereKey("contacts", containedIn: categoryArr)
I find only in the docs how the query can look like to select data.
As far as I see, there is only one way to collect 1 or many results:
var query = PFQuery(className:"GameScore")
query.whereKey("playerName", equalTo:"Sean Plott")
query.findObjectsInBackgroundWithBlock {
(objects: [AnyObject]!, error: NSError!) -> Void in
if error == nil {
// The find succeeded.
NSLog("Successfully retrieved \(objects.count) scores.")
// Do something with the found objects
for object in objects {
NSLog("%#", object.objectId)
}
} else {
// Log details of the failure
NSLog("Error: %# %#", error, error.userInfo!)
}
}
What I cant figure out (as I am a beginner!) is how to access the object data. Lets say I have the fields "name", how can I get it? What is the right syntax? Especially if I have more than 1 result?
For just one result I would do:
var name = object["name"] as String
myArray.append(name)
Even that can't be right? To use "var xx = xx" within the loop?
And what do I do when I have more than one result?
Other thought:
Declaring the var name: String! before I do the query and then:
name = object["name"] as String
self.myArray.append(name)
Returns the error: Immutable vaue of type [String] only has mutating members named 'append'
What would be the correct way to "work" with the data the query returns?
Another question: as those querys are async, they finished later and the method is "done" much more earlier, this way my array with names is empty when the view is shown and I receive the data at a later stage. What is the best practice here to have all data available before the view is delivered to the device?
Thanks so much!!
You can use objectForKey on your object. So instead of using var name = object["name"] as String you can use:
for object in objects {
var name = object.valueForKey("name") as String
}
But the other parts are absolutely fine. You can create an array somewhere in you code and then add the objects to it. to do that, you can loop through your objects and than add the objects to your array. Like that:
if error == nil {
// The find succeeded.
NSLog("Successfully retrieved \(objects.count) scores.")
// Do something with the found objects
for object in objects {
var name = object["name"] as String
myArray.append(name)
}
}
Because you can reuse the var name because every loop-element will be filled into the variable name and will erase the last value. But the array will get the new value appended. For example:
First loop. The value at the first index of your objects gets loaded into the object. For example with the value "John".
variable name's value is now the value of the object["name"] of the current loop. So name has the value John
Now you add the value to your array.
The second loop starts and the second element gets loaded inside object which now has the string Michael.
The Variable name's new value is now the value of object. So name's value is now Michael
and so on.