How can i get child nodes from firebase?
Firebase struct is here:
Me need to get a child "Photos" for each child above. And later add to collectionView each child "Photo".
My firebase struct:
{
"Студии" : {
"Бабулька" : {
"Photo" : {
"image" : "https://firebasestorage.googleapis.com/v0/b/test2-29e4b.appspot.com/o/city3.jpg?alt=media&token=12a87c0c-ade1-43f9-b76b-ecdaa86cf185"
},
"address" : "Сатурн",
"image" : "https://firebasestorage.googleapis.com/v0/b/test2-29e4b.appspot.com/o/city3.jpg?alt=media&token=12a87c0c-ade1-43f9-b76b-ecdaa86cf185",
"image1" : "https://firebasestorage.googleapis.com/v0/b/test2-29e4b.appspot.com/o/city3.jpg?alt=media&token=12a87c0c-ade1-43f9-b76b-ecdaa86cf185",
"name" : "Карапулька"
},
"Дубаи" : {
"Photo" : {
"image" : "https://firebasestorage.googleapis.com/v0/b/test2-29e4b.appspot.com/o/city1.jpg?alt=media&token=c442fd8f-4cc4-4e30-8242-975aaf5427dc"
},
"address" : "Тутушка",
"image" : "https://firebasestorage.googleapis.com/v0/b/test2-29e4b.appspot.com/o/city1.jpg?alt=media&token=c442fd8f-4cc4-4e30-8242-975aaf5427dc",
"name" : "Дубаи"
},
"Лондон" : {
"Photo" : {
"image" : "https://firebasestorage.googleapis.com/v0/b/test2-29e4b.appspot.com/o/oko1.jpg?alt=media&token=fedea2cb-93b1-496c-9392-0b95f4ada7b5"
},
"address" : "Бейкер стрит",
"image" : "https://firebasestorage.googleapis.com/v0/b/test2-29e4b.appspot.com/o/oko1.jpg?alt=media&token=fedea2cb-93b1-496c-9392-0b95f4ada7b5",
"name" : "Лондон"
}
}
}
Thanks for help.
To get to the data you want, iterate over all of the child notes of the main parent node. Assume the following structure
posts
post_0
Photo
image: "https://www....."
post_1
Photo
image: "https://www....."
and the code to get the image urls...
let ref = self.ref.child("posts")
ref.observeSingleEvent(of: .value, with: { snapshot in
for child in snapshot.children {
let snap = child as! DataSnapshot
let imageSnap = snap.childSnapshot(forPath: "Photo")
let dict = imageSnap.value as! [String: Any]
let url = dict["image"] as! String
print(url)
}
})
Related
I am trying to return the count of posts for a specific user where a field contains a certain value. The structure I am using in Firebase is here:
{
"posts" : {
"-Lyzpsb1hH4LUPvcXE3H" : {
"beverageCategory" : "Beer",
"beverageName" : "Dortmunder",
"beveragePrice" : "3.99",
"beverageRating" : 3,
"beverageType" : "Lager",
"imageUrl" : "https://firebasestorage.googleapis.com/v0/b/socialspirit-37cae.appspot.com/o/post-pics%2F3C23E923-A3BD-4393-B3EF-8F939D8B08B8?alt=media&token=ac80cb98-f2a1-4197-b328-2a69a2ac1fd1",
"wineVintage" : ""
}
},
"user" : "sdkjvksdjf",
"users" : {
"0hyN8N2klJWqPi2lkRqNK3vg7z63" : {
"posts" : {
"-Ly6ciYHm7v5JFy1VmVY" : true,
"-Ly6cyLukI6aRRki5yna" : true
},
"provider" : "Firebase"
},
"26OUuaRZEVWUmkLJp13LzirGbs13" : {
"posts" : {
"-Ly6fGmQEMZz3c-azMnJ" : true
},
"provider" : "Firebase"
},
"5r6FulsvIRap7pLK5D3zV8qyPVv1" : {
"provider" : "Firebase"
},
"gQpktBMh97hTqiysHBwvVLZl70y1" : {
"posts" : {
"-Lyzpsb1hH4LUPvcXE3H" : true,
"-LyzqFgvmrBgdsgKSt_5" : true,
"-Lz-fIMDal00ex3_viQo" : true,
"-Lz-lXsSBqKlcf8hBext" : true,
"-Lz2eNLfk1PFEVkEgmwa" : true,
"-Lz2etF0UqFqLkdGOR13" : true,
"-Lz2fGUi0qzJtniNr5LX" : true,
"-Lz2gP5c47yHDO2g0ljr" : true,
"-Lz2gdhfedZfTtzjP2ee" : true,
"-Lz2gllC3caXgPf2VAPU" : true,
"-Lz2hH8FbNmBEOLcHCJz" : true,
"-Lz2jzkXuEZ3Cfe96eGW" : true,
"-Lz3RvuW4fMXarhW7vLv" : true,
"-Lz3S8YA0vgk4ZrjL_Kk" : true
},
"provider" : "Firebase"
}
}
}
I am using the following code to get the count of records that have a beverageCategory of "Beer".
DataService.ds.REF_USERS.child("\(uid)").child("posts").child("beverageCategory")
.queryOrderedByValue().queryEqual(toValue: "Beer")
.observe(DataEventType.value, with: { (snapshot) in
print("SNAP - \(snapshot.childrenCount)")
})
The childrenCount returns 0, however. Any idea what I'm doing wrong here? Thanks!
EDIT: I added the JSON for the data structure and I think I left an important detail out. The data structure actually has users that have posts and the associated postid that links back to posts. I think what I have to do is first find the user's posts and then of those posts get a total count for each category. I'm guessing that is slightly different than the methods I tried. Any ideas on that?
EDIT 2: So my issues is that users and posts are in different structures. I need to find all of the user's posts and iterate through them to see if what the beverageCategory is. I have done that with the following code. The issue with the code below is that the count is doubled when I add a post and then open the menu. But when I exit the menu and re-open the count is correct. Why is it double-counting?
func myFirebaseNetworkDataRequest(finished: #escaping () -> Void) {
beerCountArray.removeAll()
wineCountArray.removeAll()
liquorCountArray.removeAll()
print("BEER ARRAY \(beerCountArray.count)")
guard let uid = Auth.auth().currentUser?.uid else {
return
}
let newPost = DataService.ds.REF_USERS.child("\(uid)").child("posts")
newPost.observe(.value, with: { (snapshot) in
if let snapshot = snapshot.children.allObjects as? [DataSnapshot] {
//print("SNAPSHOT - \(snapshot)")
for snap in snapshot {
let postData = DataService.ds.REF_POSTS.child(snap.key)
//print("SNAP KEY - \(snap.key)")
let bevCat = DataService.ds.REF_POSTS.child(snap.key).child("beverageCategory")
//print("BEV CAT - \(bevCat)")
postData.observe(.value, with: { (snapshot) in
if let postDict = snapshot.value as? Dictionary<String, AnyObject> {
let key = snapshot.key
let post = Post(postKey: key, postData: postDict)
//print("POST DICT - \(String(describing: postDict["beverageCategory"]!))")
if postDict["beverageCategory"]! as! String == "Beer" {
self.beerCountArray.append(1)
//print("BEER ARRAY LOOP - \(self.beerCountArray)")
}
if postDict["beverageCategory"]! as! String == "Wine"{
self.wineCountArray.append(1)
}
if postDict["beverageCategory"]! as! String == "Liquor" {
self.liquorCountArray.append(1)
}
//self.posts.append(post)
}
finished()
})
}
}
})
}
And...
override func viewDidLoad() {
super.viewDidLoad()
beerCountArray.removeAll()
wineCountArray.removeAll()
liquorCountArray.removeAll()
myFirebaseNetworkDataRequest {
//print("BEER ARRAY - \(self.beerCountArray.count)")
self.beerCount.text = String(self.beerCountArray.count)
self.liquorCount.text = String(self.liquorCountArray.count)
self.wineCount.text = String(self.wineCountArray.count)
}
}
Your query is not correct. Since you're trying to filter on a child property of each node under posts, you should call queryOrdered(byChild:).
So:
DataService.ds.REF_USERS.child("posts")
.queryOrdered(byChild: "beverageCategory")
.queryEqual(toValue: "Beer")
.observe(DataEventType.value, with: { (snapshot) in
print("SNAP - \(snapshot.childrenCount)")
})
Also see the Firebase documentation on ordering and filtering data.
Is there a way to dynamically get a child database from the parent instance, without having to use childByAutoId () ?
{
"artists" : {
"artists_id_1" : {
"name" : "Atif Aslam",
"genre" : "Rock"
},
"artists_id_2" : {
"name" : "Arijit Singh",
"genre" : "Rock"
}
}
}
we usually refer to the path, and listener the items the DataBase...Example:
Database.database().reference().child("artists").child("artist_id_1").observeSingleEvent(of: .value, with: { (snapshot) in
if let dictionary = snapshot.value as? [String: AnyObject] {
print("\(String(describing: dictionary["name"] as? String))")
}
}, withCancel: nil)
it would only work for the first item. Because, it would not be dynamic. What is normally used is the following example below ...
{
"artists" : {
"-KeZUDrJv555kteAcssL-" : {
"name" : "Atif Aslam",
"genre" : "Rock"
},
"-KeZUVXFIQdO7JiyRYk-" : {
"name" : "Arijit Singh",
"genre" : "Rock"
}
}
}
Database.database().reference().child("artists").childByAutoId().observeSingleEvent(of: .value, with: { (snapshot) in
if let dictionary = snapshot.value as? [String: AnyObject] {
print("\(String(describing: dictionary["name"] as? String))")
}
}, withCancel: nil)
Anyway, I do not know if it was clear, anything can comment before answering. Thank you
To display all artists in your database, load the artists node and loop over snapshot.children:
Database.database().reference().child("artists").observe(.value) { (snap:DataSnapshot) in
for child in snapshot.children {
print(child.key)
}
}
For this and more examples, I recommend reading the Firebase documentation, specifically the section on reading and writing lists.
I dont know if i understand your question correctly or what you are trying to do but maybe you can try
Database.database().reference().child("artists").observe(.value) { (snap:DataSnapshot) in
// This should print out your childIds
print(snap.key)
// This should print out the values after them
print(snap.value)
}
"-KHbCuQflKHrJiUmfpG0" : {
"waypoints" : {
"-KHbCuQflKHrJiUmfpG1" : {
"latitude" : 13.17078652595298,
"longitude" : -59.5775944578738
},
"-KHbCuQflKHrJiUmfpG2" : {
"latitude" : 13.15541190861343,
"longitude" : -59.57619643155932
},
"-KHbCuQg9W_tebl1pU66" : {
"latitude" : 13.148444967591,
"longitude" : -59.5589266947333
}
},
"subtitle" : "jamesrick",
"title" : "Highway",
"type" : "polyline"
},
I have this structure for lines in Firebase. How retrieve all data with also nested node waypoints?
ref.observeEventType(.Value, withBlock: { polylines in
if let objects = polylines.children.allObjects as? [FDataSnapshot] {
for object in objects {
polylineDictionary = object.values as? Dictionary<String, AnyObjects> {
// ? ? ?
}
}
}
})
Now I have access to title, subtitle, type but how obtain access to waypoints? When I use
`polylineDictionary["waypoints"] as? [String: [String:Double]]`
so this dictionaries are not ordered. Thanks for some advice.
This is how I would get the nested waypoints... it's basically by iterating through the keys... I would also add some error checking when grabbing the longitude and latitudes to make sure they're there, but this is the gist:
if let polylineDictionary["waypoints"] as? [String: [String:Double]] {
let waypoints = Array(polylineDictionary.keys)
for i in 0..<waypoints.count {
let waypointId = waypoints[i]
let latitude = polylineDictionary[waypointId]["latitude"]
let longitutde = polylineDictionary[waypointId]["longitude"]
}
}
It's not clear from the question about ordering; if you just want to get to the waypoints, it's pretty straight forward:
Assume your complete Firebase structure is:
root_node
"-KHbCuQflKHrJiUmfpG0" : {
"waypoints" : {
"-KHbCuQflKHrJiUmfpG1" : {
"latitude" : 13.17078652595298,
"longitude" : -59.5775944578738
},
"-KHbCuQflKHrJiUmfpG2" : {
"latitude" : 13.15541190861343,
"longitude" : -59.57619643155932
},
"-KHbCuQg9W_tebl1pU66" : {
"latitude" : 13.148444967591,
"longitude" : -59.5589266947333
}
},
"subtitle" : "jamesrick",
"title" : "Highway",
"type" : "polyline"
}
Suppose I want the data for this specific node, -KHbCuQflKHrJiUmfpG0
let nodeRef = rootRef.childByAppendingPath("-KHbCuQflKHrJiUmfpG0")
nodeRef.observeSingleEventOfType(.Value , withBlock: { snapshot in
print(snapshot.value) //prints everything in the node
let title = snapshot.value["title"] as! String //to get any element
print(title) //prints Highway
var waypoints = [String: [String:String]]() //dict to hold key:value, unordered
waypoints = snapshot.value["waypoints"] as! Dictionary
print(waypoints) //prints the 3 waypoints and their children (as a dict)
//get fancy and convert the dictionary to an array (which can be sorted)
let arr = waypoints.map {"\($0) \($1)"}
for point in arr {
print(point)
}
}
"-KHbCuQflKHrJiUmfpG0" : {
"coordinates" : {
"-KHbCuQflKHrJiUmfpG1" : {
"latitude" : 13.17078652595298,
"longitude" : -59.5775944578738
},
"-KHbCuQflKHrJiUmfpG2" : {
"latitude" : 13.15541190861343,
"longitude" : -59.57619643155932
},
"-KHbCuQg9W_tebl1pU66" : {
"latitude" : 13.148444967591,
"longitude" : -59.5589266947333
}
},
"subtitle" : "patrick",
"title" : "River",
"type" : "polyline"
},
This is my JSON structure for saving polylines and I need retrieve coordinates in same order.
This is my code for obtaining coordinates and creating polylines.
// geoobject.key - is ID of geoobject (for loop geoobjects) "-KHbCuQflKHrJiUmfpG0"
DataService.dataService.getGeoObject(geoobject.key).observeEventType(.Value, withBlock: { geoSnapshot in
var coordinatesPolyline = [CLLocationCoordinate2D]()
if let geoDictionary = geoSnapshot.value as? Dictionary<String, AnyObject> {
let id = geoSnapshot.key
if geoDictionary["type"] as! String == "polyline" {
if let coords = geoDictionary["coordinates"] as? [String:[String:Double]] {
let contents = coords.values
for content in contents {
let latitude = content["latitude"]
let longitude = content["longitude"]
let point = CLLocationCoordinate2D(latitude: latitude!, longitude: longitude!)
coordinatesPolyline.append(point)
}
// coordintesPolyline contains shuffle coordinates
let polyline = Polyline(coordinates: &coordinatesPolyline, count: coordinatesPolyline.count)
//coordinates = []
polyline.id = geoSnapshot.key
polyline.title = geoDictionary["title"] as? String
polyline.subtitle = geoDictionary["subtitle"] as? String
self.polylines.insert(polyline, atIndex: 0)
}
}
})
I rendered polylines but polylines are renderder bad because coordinates are shuffle.
Does anyone know how to get coordinates in the correct order. Firebase retrieve coordinates shuffle and then rendering doesn't work well.
Thank you for some advice.
When reading firebase data by .Value, ALL of the data within the node is returned in the snapshot.
If you want the data in a specific order, you need to decide what 'thing' you want it ordered by. The natural order is by key, but if you want it ordered by some other parameter, you need to include that in you firebase structure, and then add orderedBy to your observe.
One you have the data by .Value, you then need to iterate over each child within the snapshot to access that nodes data. For example
If your Firbase structure is
"coordinates" : {
"-KHbCuQflKHrJiUmfpG1" : {
"latitude" : 13.17078652595298,
"longitude" : -59.5775944578738
},
"-KHbCuQflKHrJiUmfpG2" : {
"latitude" : 13.15541190861343,
"longitude" : -59.57619643155932
},
"-KHbCuQg9W_tebl1pU66" : {
"latitude" : 13.148444967591,
"longitude" : -59.5589266947333
}
Then the snapshot contains All of that data. Iterate over the snapshot and work with each child:
ref.observeEventType(.Value, withBlock: { geoSnapshot in
for child in geoSnapshot.children {
let lat = child["latitude"] as? String
let long = child["longitude"] as? String
print("lat = \(lat) long = \(long)"
}
})
(didn't test that code but it's close)
Oh, and one other thing. ObserveEventOfType(.Value) will continually observe the node for changes - add, change or remove and will fire any time one of those events occur.
If you just want a one-shot, use ObserveSingleEventOfType(.Value)
Hello i've been trying to make a json request and some of its results i want to put it to an array of string.
So i have the following code
var arrRes = [[String:AnyObject]]()
var nameaRR = [String]()
override func viewDidLoad() {
super.viewDidLoad()
Alamofire.request(.GET, "https://graph.facebook.com/search", parameters: ["q": "", "type": "place", "center": "37.928319,23.7036673", "distance": "10000","limit": "1000", "access_token": "SomeToken", "expires_in": "5184000"])
.responseJSON { (responseData) -> Void in
if((responseData.result.value) != nil) {
let swiftyJsonVar = JSON(responseData.result.value!)
//print(swiftyJsonVar)
if let resData = swiftyJsonVar["data"].arrayObject {
self.arrRes = resData as! [[String:AnyObject]]
self.nameaRR = swiftyJsonVar["data"]["name"] as! [String]
print(self.nameaRR)
}
if self.arrRes.count > 0 {
self.kati.reloadData()
}
}
}
}
The JSON Resul is the following
{
"data" : [
{
"category_list" : [
{
"id" : "272705352802676",
"name" : "Outdoors"
},
{
"id" : "115725465228008",
"name" : "Region"
}
],
"id" : "552889064768971",
"name" : "Παλαιο Φαληρο", //This String i want to put in an Array
"category" : "Local business",
"location" : {
"street" : "",
"city" : "Palaión Fáliron",
"country" : "Greece",
"longitude" : 23.6944070162,
"zip" : "17562",
"latitude" : 37.9284637008,
"state" : ""
}
}
]
}
I get a warning
Cast from 'JSON' to unrelated type '[String]' always fails
But i'm stuck of how can i put all the Strngs to the array nameaRR.
Can anyone help me find my mistake? Thanks!
look do like that
if let resData = swiftyJsonVar["data"] as? [[String:AnyObject]] {
if let categorylist = resData["category_list"] as? [[String:AnyObject]]{
if let id = categorylist["id"] as? Int{
print(id)
}
}
}