Storing an array in a Firebase Database - arrays

I am trying to store an array in the Firebase Database, but I'm not sure how to do it properly.
I am wanting to store an array such as:
var exampleArray = ["item1", "item2", "item3"]
The reason why is I populate a UIPicker with values from an array, and rather than having to push an update to the app each time to add a new value, it would be better if I could just update the database and instantly add the new value to each app.
Is there any way that I could store the values in the database and pull the values from the database and store it into an array as shown above?
Thank you.

The Firebase setValue method will accept an array just the same as a String or Integer. So you can read and write the values in the same way -
var ref: DatabaseReference!
ref = Database.database().reference()
var exampleArray = ["item1", "item2", "item3"]
// Write the array
ref.child("myArray").setValue(exampleArray)
// Read the array
ref.child("myArray").observe(.value) { snapshot in
for child in snapshot.children {
// Add the values to your picker array here
}
}

A simple solution would be read JSON from a Firebase Database Reference containing the array, and deserealize it in swift to a native swift array. See point 2 at https://firebase.google.com/docs/database/#implementation_path

Related

Best approach in moving data from one array to a new array in angular ts

.subscribe((dataChart) => {
// console.log(dataChart)
var forxaxis = []
var cd = [dataChart]
// console.log(cd)
cd.forEach(element => {
forxaxis.push(element.strRequestDate)
console.log(forxaxis)
});
},
Im trying to move my data in the first array into a new array so that I can use it with chart.js. but it didnt work.
dataChart contain 2 column of data. i insert dataChart into an array called cd. then i tried to push one of the column from dataChart which is called strRequestDate into a new array called forxaxis but it just didnt work as per expected. the result is as shown in the image attached.
this is how the data look like. it was called by using sharepoint API
error and the data
You can use array.map property here, so you don't need to push data manually from one array to another
I have taken sample data in dataChart array for demonstration purpose only.
let dataChart = [{strRequestId: 1, strRequestDate: 'ABC'}, {strRequestId: 1, strRequestDate: 'PQR'}];
let forxaxis = dataChart.map(x => x.strRequestDate);
console.log(forxaxis);
Demo
Output:

Compare data between two Arrays containing custom Swift Objects

I have some data I have received through an API that return JSON to me. I know I can fetch it and store relevant info from the API into my iOS app. But only while the app is running. I.E. I have not implemented YET how to store the info fetched from the API into UserDefalults. Working on this feature I ran into a problem.
I have two Arrays that keeps track of my data. The first Array is the Array I want to store in UserDefaults when I have fetch my data. This one is called "lenders" and keeps LenderData
The second Array is my temporary Array. It contains the same type of objects, and this is the one I want to populate with data from the API and then compare to my existing Array "lenders".
I want to check if the "lenders" Array contains any object that has the same id as the object I'm looking at in the "lendersTemp" array. If the lenders Array does not contain any LederData object with the id of the tempLender we are currently looking at, we add the tempLender into the lenders Array. How would I go about doing this?
My current (non-working) solution is as follows:
var lenders = [LenderData]()
var lendersTemp = [LenderData]()
...
// Get JSON DATA
...
for tempLender in self.lendersTemp {
if !self.lenders.contains(where: {$0.id == tempLender.id}) {
self.lenders.append(tempLender)
}
}
EDIT:
My view did load method:
var lenders = [LenderData]()
var lendersTemp = [LenderData]()
override func viewDidLoad() {
super.viewDidLoad()
downloadJSON {
self.myTableView.reloadData()
}
self.myTableView.rowHeight = 90
myTableView.delegate = self
myTableView.dataSource = self
}
I figured it out with some help! So this is my answer to my own question!
My problem was that getting data from my API is done with an asyc method. And I tried to do comparison after the reload method was called on my TableView. So I did not populate the array the tableview is getting data from, before after the reloadData() had been called and therefore it seemed like my tableview and comparison algorithm, did not work, when in fact it did!

AngularJS Firebase get the list of object keys

Here is my Firebase database, I want to get the object keys as a list:
var mydb = DatabaseRef.ref("projects").orderByKey();
$scope.mylist= $firebaseArray(mydb);
var data = $scope.mylist;
How can I get the keys of the object of data as array list?
You can use Object.keys in this scenario.
It will return an array of strings that represents the properties of the object (keys).

How to map new property values to an array of JSON objects?

I'm reading back record sets in an express server using the node mssql package. Reading back the values outputs an array of Json objects as expected.
Now I need to modify the Email propoerty value of each Json object. So I tried looping through the recordset and changing the value at each index:
var request = new sql.Request(sql.globalConnection);
request.input('p_email', sql.VarChar(50), userEmail);
request.execute('GetDDMUserProfile', function(err, recordsets, returnValue) {
for (var i = 0; i < recordsets.length; i++){
recordsets[i].Email = "joe#gmail.com";
}
console.log(recordsets);
});
But instead of modifying the Emailvalue of each Json object, this code just appends a new email property to the last Json object.
How can you map new property values to an array of JSON objects?
Example output:
An example of the output is shown below, where a new Email property has been added to the end of the array instead of changing each existing property value:
[
[
{
ID:[
4
],
UserName:"Brian",
Email:"joe#gmail.com"
},
{
ID:[
5
],
UserName:"Brian",
Email:"joe#gmail.com"
}
Email:'joe#gmail.com' ]
]
The issue here is that your dataset appears to not be an array of JSON objects but, rather, an array of arrays of JSON objects. If you know for certain that you'll always have only one array in the top-most array, then you can solve the problem like this:
recordsets[0][i].Email = "joe#gmail.com";
to always target the first array in the top-most array. However, if the top-most array could potentially have more than one array, that'll be a different kind of issue to solve.

How to loop through array of objects from Firebase?

I am trying to loop through an array object retrived from Firebase:
var announcementsRef = new Firebase(FIREBASE_URL+'/annoucements');
$scope.announcements = $firebaseObject(announcementsRef);
I display it in console :
image.
I tried to display the first object message like this
console.log($scope.announcements[1].message).
But it does not shows me
How can I solve this ?
If what's stored on Firebase it's an array, the way to use it is with $firebaseArray(ref);
Check the guide for more info https://www.firebase.com/docs/web/libraries/angular/guide/synchronized-arrays.html

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