Randomly select an array from group of "enabled" arrays - swift

I have a set of four arrays. I also have an option to either enable or disable 3 of the 4 arrays (one is always enabled).
Is there a way to randomly decide which array to pull a value from (of the arrays indicated as enabled)?
I originally was aiming to make a master array and just append the content of the other enabled ones into it, but it proved a little harder than expected. I figured it would be easier to simply randomly select an array to pull the single value from as long as it was "enabled".
I'm currently pulling the value with a simple statement such as
If ????? {
return promptArrayA[desiredIndexA]
} else if { ?????
return promptArrayB[desiredIndexB]
} else if { ?????
return promptArrayC[desiredIndexC]
} else {
return promptArrayD[desiredIndexD]
I'm thinking if I had a "randomizer" that chose one of the enabled arrays, then I can use that as a constraint in an If Statement.
I'm fairly new to Swift so any help is much appreciated. Thank you

You can get the array randomly by doing:
let enabledArrays = [promptArrayA, promptArrayB, promptArrayC, promptArrayD]
let randomIndex = Int.random(in: 0..<enabledArrays.count)
let randomArray = enabledArrays[randomIndex]
return randomArray[desiredIndex]

Related

Salesforce trigger-Not able to understand

Below is the code written by my collegue who doesnt work in the firm anymore. I am inserting records in object with data loader and I can see success message but I do not see any records in my object. I am not able to understand what below trigger is doing.Please someone help me understand as I am new to salesforce.
trigger DataLoggingTrigger on QMBDataLogging__c (after insert) {
Map<string,Schema.RecordTypeInfo> recordTypeInfo = Schema.SObjectType.QMB_Initial_Letter__c.getRecordTypeInfosByName();
List<QMBDataLogging__c> logList = (List<QMBDataLogging__c>)Trigger.new;
List<Sobject> sobjList = (List<Sobject>)Type.forName('List<'+'QMB_Initial_Letter__c'+'>').newInstance();
Map<string, QMBLetteTypeToVfPage__c> QMBLetteTypeToVfPage = QMBLetteTypeToVfPage__c.getAll();
Map<String,QMBLetteTypeToVfPage__c> mapofLetterTypeRec = new Map<String,QMBLetteTypeToVfPage__c>();
set<Id>processdIds = new set<Id>();
for(string key : QMBLetteTypeToVfPage.keyset())
{
if(!mapofLetterTypeRec.containsKey(key)) mapofLetterTypeRec.put(QMBLetteTypeToVfPage.get(Key).Letter_Type__c, QMBLetteTypeToVfPage.get(Key));
}
for(QMBDataLogging__c log : logList)
{
Sobject logRecord = (sobject)log;
Sobject QMBLetterRecord = new QMB_Initial_Letter__c();
if(mapofLetterTypeRec.containskey(log.Field1__c))
{
string recordTypeId = recordTypeInfo.get(mapofLetterTypeRec.get(log.Field1__c).RecordType__c).isAvailable() ? recordTypeInfo.get(mapofLetterTypeRec.get(log.Field1__c).RecordType__c).getRecordTypeId() : recordTypeInfo.get('Master').getRecordTypeId();
string fieldApiNames = mapofLetterTypeRec.containskey(log.Field1__c) ? mapofLetterTypeRec.get(log.Field1__c).FieldAPINames__c : '';
//QMBLetterRecord.put('Letter_Type__c',log.Name);
QMBLetterRecord.put('RecordTypeId',tgh);
processdIds.add(log.Id);
if(string.isNotBlank(fieldApiNames) && fieldApiNames.contains(','))
{
Integer i = 1;
for(string fieldApiName : fieldApiNames.split(','))
{
string logFieldApiName = 'Field'+i+'__c';
fieldApiName = fieldApiName.trim();
system.debug('fieldApiName=='+fieldApiName);
Schema.DisplayType fielddataType = getFieldType('QMB_Initial_Letter__c',fieldApiName);
if(fielddataType == Schema.DisplayType.Date)
{
Date dateValue = Date.parse(string.valueof(logRecord.get(logFieldApiName)));
QMBLetterRecord.put(fieldApiName,dateValue);
}
else if(fielddataType == Schema.DisplayType.DOUBLE)
{
string value = (string)logRecord.get(logFieldApiName);
Double dec = Double.valueOf(value.replace(',',''));
QMBLetterRecord.put(fieldApiName,dec);
}
else if(fielddataType == Schema.DisplayType.CURRENCY)
{
Decimal decimalValue = Decimal.valueOf((string)logRecord.get(logFieldApiName));
QMBLetterRecord.put(fieldApiName,decimalValue);
}
else if(fielddataType == Schema.DisplayType.INTEGER)
{
string value = (string)logRecord.get(logFieldApiName);
Integer integerValue = Integer.valueOf(value.replace(',',''));
QMBLetterRecord.put(fieldApiName,integerValue);
}
else if(fielddataType == Schema.DisplayType.DATETIME)
{
DateTime dateTimeValue = DateTime.valueOf(logRecord.get(logFieldApiName));
QMBLetterRecord.put(fieldApiName,dateTimeValue);
}
else
{
QMBLetterRecord.put(fieldApiName,logRecord.get(logFieldApiName));
}
i++;
}
}
}
sobjList.add(QMBLetterRecord);
}
if(!sobjList.isEmpty())
{
insert sobjList;
if(!processdIds.isEmpty()) DeleteDoAsLoggingRecords.deleteTheProcessRecords(processdIds);
}
Public static Schema.DisplayType getFieldType(string objectName,string fieldName)
{
SObjectType r = ((SObject)(Type.forName('Schema.'+objectName).newInstance())).getSObjectType();
DescribeSObjectResult d = r.getDescribe();
return(d.fields.getMap().get(fieldName).getDescribe().getType());
}
}
You might be looking in the wrong place. Check if there's an unit test written for this thing (there should be one, especially if it's deployed to production), it should help you understand how it's supposed to be used.
You're inserting records of QMBDataLogging__c but then it seems they're immediately deleted in DeleteDoAsLoggingRecords.deleteTheProcessRecords(processdIds). Whether whatever this thing was supposed to do succeeds or not.
This seems to be some poor man's CSV parser or generic "upload anything"... that takes data stored in QMBDataLogging__c and creates QMB_Initial_Letter__c out of it.
QMBLetteTypeToVfPage__c.getAll() suggests you could go to Setup -> Custom Settings, try to find this thing and examine. Maybe it has some values in production but in your sandbox it's empty and that's why essentially nothing works? Or maybe some values that are there are outdated?
There's some comparison if what you upload into Field1__c can be matched to what's in that custom setting. I guess you load some kind of subtype of your QMB_Initial_Letter__c in there. Record Type name and list of fields to read from your log record is also fetched from custom setting based on that match.
Then this thing takes what you pasted, looks at the list of fields in from the custom setting and parses it.
Let's say the custom setting contains something like
Name = XYZ, FieldAPINames__c = 'Name,SomePicklist__c,SomeDate__c,IsActive__c'
This thing will look at first record you inserted, let's say you have the CSV like that
Field1__c,Field2__c,Field3__c,Field4__c
XYZ,Closed,2022-09-15,true
This thing will try to parse and map it so eventually you create record that a "normal" apex code would express as
new QMB_Initial_Letter__c(
Name = 'XYZ',
SomePicklist__c = 'Closed',
SomeDate__c = Date.parse('2022-09-15'),
IsActive__c = true
);
It's pretty fragile, as you probably already know. And because parsing CSV is an art - I expect it to absolutely crash and burn when text with commas in it shows up (some text,"text, with commas in it, should be quoted",more text).
In theory admin can change mapping in setup - but then they'd need to add new field anyway to the loaded file. Overcomplicated. I guess somebody did it to solve issue with Record Type Ids - but there are better ways to achieve that and still have normal CSV file with normal columns and strong type matching, not just chucking everything in as strings.
In theory this lets you have "jagged" csv files (row 1 having 5 fields, row 2 having different record type and 17 fields? no problem)
Your call whether it's salvageable or you'd rather ditch it and try normal loading of QMB_Initial_Letter__c records. (get back to your business people and ask for requirements?) If you do have variable number of columns at source - you'd need to standardise it or group the data so only 1 "type" of records (well, whatever's in that "Field1__c") goes into each file.

Eliminate repetition in updating strings selected randomly within a state property

First, I'm very new to Swift, and coding in general. I'm trying to use the correct terminology, so I apologize if it makes no sense. Doing my best!
Ok, so there appears to be a lot of information/answers on ways to random select strings (or integers, etc) from an array without repetition. However, in my current application, I am not using an array (I kind of am but not directly related to the question). But rather a #State designation, in which the variable has an initial value (a string with a number and letter) and is later updated when a button is pushed. The string changes to a randomly selected string from my assets folder based on the file name, which will be the same word but with a different number and letter. What is the simplest way to keep from updating to strings that have already appeared?
Example of what the code looks like:
#State var relevantWord = "bird"
Button {
let randoNum = Int.random(in: 1...5)
let x = ["a", "b", "c", "d"]
let randoLet = x.randomElement()
relevantWord = "bird" + String(randoNum) + String(randoLet)
}
So, the relevantWord variable starts as "bird2c" for example, and each time the button is pushed, it will change to "bird3b" then "bird4a" etc. I just want to keep it from repeating and return nothing when the assets are depleted. Thanks!

How to get the index of randomElement

I want to know how I can get the index of an array in Swift if I use randomElement.
Example :
I've an array from a JSON file. After each click on a button, I want to change the label by a value from the array.
I want to looping through the array for print the value and delete this after the display. The problem is I don't see how I get the current value to delete her.
if let rand = myArray.randomElement() {
myLabel.text = rand.question
}
I've seen more options to make a random in array but with after reading some articles for Swift 4.2, the best practice is to use randomElement().
A simple solution is to get a random index
if let index = myArray.indices.randomElement() {
myLabel.text = myArray[index].question
}

Reverse display order in UITableView of Childs retrieved from Firebase Database [duplicate]

I'm trying to test out Firebase to allow users to post comments using push. I want to display the data I retrieve with the following;
fbl.child('sell').limit(20).on("value", function(fbdata) {
// handle data display here
}
The problem is the data is returned in order of oldest to newest - I want it in reversed order. Can Firebase do this?
Since this answer was written, Firebase has added a feature that allows ordering by any child or by value. So there are now four ways to order data: by key, by value, by priority, or by the value of any named child. See this blog post that introduces the new ordering capabilities.
The basic approaches remain the same though:
1. Add a child property with the inverted timestamp and then order on that.
2. Read the children in ascending order and then invert them on the client.
Firebase supports retrieving child nodes of a collection in two ways:
by name
by priority
What you're getting now is by name, which happens to be chronological. That's no coincidence btw: when you push an item into a collection, the name is generated to ensure the children are ordered in this way. To quote the Firebase documentation for push:
The unique name generated by push() is prefixed with a client-generated timestamp so that the resulting list will be chronologically-sorted.
The Firebase guide on ordered data has this to say on the topic:
How Data is Ordered
By default, children at a Firebase node are sorted lexicographically by name. Using push() can generate child names that naturally sort chronologically, but many applications require their data to be sorted in other ways. Firebase lets developers specify the ordering of items in a list by specifying a custom priority for each item.
The simplest way to get the behavior you want is to also specify an always-decreasing priority when you add the item:
var ref = new Firebase('https://your.firebaseio.com/sell');
var item = ref.push();
item.setWithPriority(yourObject, 0 - Date.now());
Update
You'll also have to retrieve the children differently:
fbl.child('sell').startAt().limitToLast(20).on('child_added', function(fbdata) {
console.log(fbdata.exportVal());
})
In my test using on('child_added' ensures that the last few children added are returned in reverse chronological order. Using on('value' on the other hand, returns them in the order of their name.
Be sure to read the section "Reading ordered data", which explains the usage of the child_* events to retrieve (ordered) children.
A bin to demonstrate this: http://jsbin.com/nonawe/3/watch?js,console
Since firebase 2.0.x you can use limitLast() to achieve that:
fbl.child('sell').orderByValue().limitLast(20).on("value", function(fbdataSnapshot) {
// fbdataSnapshot is returned in the ascending order
// you will still need to order these 20 items in
// in a descending order
}
Here's a link to the announcement: More querying capabilities in Firebase
To augment Frank's answer, it's also possible to grab the most recent records--even if you haven't bothered to order them using priorities--by simply using endAt().limit(x) like this demo:
var fb = new Firebase(URL);
// listen for all changes and update
fb.endAt().limit(100).on('value', update);
// print the output of our array
function update(snap) {
var list = [];
snap.forEach(function(ss) {
var data = ss.val();
data['.priority'] = ss.getPriority();
data['.name'] = ss.name();
list.unshift(data);
});
// print/process the results...
}
Note that this is quite performant even up to perhaps a thousand records (assuming the payloads are small). For more robust usages, Frank's answer is authoritative and much more scalable.
This brute force can also be optimized to work with bigger data or more records by doing things like monitoring child_added/child_removed/child_moved events in lieu of value, and using a debounce to apply DOM updates in bulk instead of individually.
DOM updates, naturally, are a stinker regardless of the approach, once you get into the hundreds of elements, so the debounce approach (or a React.js solution, which is essentially an uber debounce) is a great tool to have.
There is really no way but seems we have the recyclerview we can have this
query=mCommentsReference.orderByChild("date_added");
query.keepSynced(true);
// Initialize Views
mRecyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
mManager = new LinearLayoutManager(getContext());
// mManager.setReverseLayout(false);
mManager.setReverseLayout(true);
mManager.setStackFromEnd(true);
mRecyclerView.setHasFixedSize(true);
mRecyclerView.setLayoutManager(mManager);
I have a date variable (long) and wanted to keep the newest items on top of the list. So what I did was:
Add a new long field 'dateInverse'
Add a new method called 'getDateInverse', which just returns: Long.MAX_VALUE - date;
Create my query with: .orderByChild("dateInverse")
Presto! :p
You are searching limitTolast(Int x) .This will give you the last "x" higher elements of your database (they are in ascending order) but they are the "x" higher elements
if you got in your database {10,300,150,240,2,24,220}
this method:
myFirebaseRef.orderByChild("highScore").limitToLast(4)
will retrive you : {150,220,240,300}
In Android there is a way to actually reverse the data in an Arraylist of objects through the Adapter. In my case I could not use the LayoutManager to reverse the results in descending order since I was using a horizontal Recyclerview to display the data. Setting the following parameters to the recyclerview messed up my UI experience:
llManager.setReverseLayout(true);
llManager.setStackFromEnd(true);
The only working way I found around this was through the BindViewHolder method of the RecyclerView adapter:
#Override
public void onBindViewHolder(final RecyclerView.ViewHolder holder, int position) {
final SuperPost superPost = superList.get(getItemCount() - position - 1);
}
Hope this answer will help all the devs out there who are struggling with this issue in Firebase.
Firebase: How to display a thread of items in reverse order with a limit for each request and an indicator for a "load more" button.
This will get the last 10 items of the list
FBRef.child("childName")
.limitToLast(loadMoreLimit) // loadMoreLimit = 10 for example
This will get the last 10 items. Grab the id of the last record in the list and save for the load more functionality. Next, convert the collection of objects into and an array and do a list.reverse().
LOAD MORE Functionality: The next call will do two things, it will get the next sequence of list items based on the reference id from the first request and give you an indicator if you need to display the "load more" button.
this.FBRef
.child("childName")
.endAt(null, lastThreadId) // Get this from the previous step
.limitToLast(loadMoreLimit+2)
You will need to strip the first and last item of this object collection. The first item is the reference to get this list. The last item is an indicator for the show more button.
I have a bunch of other logic that will keep everything clean. You will need to add this code only for the load more functionality.
list = snapObjectAsArray; // The list is an array from snapObject
lastItemId = key; // get the first key of the list
if (list.length < loadMoreLimit+1) {
lastItemId = false;
}
if (list.length > loadMoreLimit+1) {
list.pop();
}
if (list.length > loadMoreLimit) {
list.shift();
}
// Return the list.reverse() and lastItemId
// If lastItemId is an ID, it will be used for the next reference and a flag to show the "load more" button.
}
I'm using ReactFire for easy Firebase integration.
Basically, it helps me storing the datas into the component state, as an array. Then, all I have to use is the reverse() function (read more)
Here is how I achieve this :
import React, { Component, PropTypes } from 'react';
import ReactMixin from 'react-mixin';
import ReactFireMixin from 'reactfire';
import Firebase from '../../../utils/firebaseUtils'; // Firebase.initializeApp(config);
#ReactMixin.decorate(ReactFireMixin)
export default class Add extends Component {
constructor(args) {
super(args);
this.state = {
articles: []
};
}
componentWillMount() {
let ref = Firebase.database().ref('articles').orderByChild('insertDate').limitToLast(10);
this.bindAsArray(ref, 'articles'); // bind retrieved data to this.state.articles
}
render() {
return (
<div>
{
this.state.articles.reverse().map(function(article) {
return <div>{article.title}</div>
})
}
</div>
);
}
}
There is a better way. You should order by negative server timestamp. How to get negative server timestamp even offline? There is an hidden field which helps. Related snippet from documentation:
var offsetRef = new Firebase("https://<YOUR-FIREBASE-APP>.firebaseio.com/.info/serverTimeOffset");
offsetRef.on("value", function(snap) {
var offset = snap.val();
var estimatedServerTimeMs = new Date().getTime() + offset;
});
To add to Dave Vávra's answer, I use a negative timestamp as my sort_key like so
Setting
const timestamp = new Date().getTime();
const data = {
name: 'John Doe',
city: 'New York',
sort_key: timestamp * -1 // Gets the negative value of the timestamp
}
Getting
const ref = firebase.database().ref('business-images').child(id);
const query = ref.orderByChild('sort_key');
return $firebaseArray(query); // AngularFire function
This fetches all objects from newest to oldest. You can also $indexOn the sortKey to make it run even faster
I had this problem too, I found a very simple solution to this that doesn't involved manipulating the data in anyway. If you are rending the result to the DOM, in a list of some sort. You can use flexbox and setup a class to reverse the elements in their container.
.reverse {
display: flex;
flex-direction: column-reverse;
}
myarray.reverse(); or this.myitems = items.map(item => item).reverse();
I did this by prepend.
query.orderByChild('sell').limitToLast(4).on("value", function(snapshot){
snapshot.forEach(function (childSnapshot) {
// PREPEND
});
});
Someone has pointed out that there are 2 ways to do this:
Manipulate the data client-side
Make a query that will order the data
The easiest way that I have found to do this is to use option 1, but through a LinkedList. I just append each of the objects to the front of the stack. It is flexible enough to still allow the list to be used in a ListView or RecyclerView. This way even though they come in order oldest to newest, you can still view, or retrieve, newest to oldest.
You can add a column named orderColumn where you save time as
Long refrenceTime = "large future time";
Long currentTime = "currentTime";
Long order = refrenceTime - currentTime;
now save Long order in column named orderColumn and when you retrieve data
as orderBy(orderColumn) you will get what you need.
just use reverse() on the array , suppose if you are storing the values to an array items[] then do a this.items.reverse()
ref.subscribe(snapshots => {
this.loading.dismiss();
this.items = [];
snapshots.forEach(snapshot => {
this.items.push(snapshot);
});
**this.items.reverse();**
},
For me it was limitToLast that worked. I also found out that limitLast is NOT a function:)
const query = messagesRef.orderBy('createdAt', 'asc').limitToLast(25);
The above is what worked for me.
PRINT in reverse order
Let's think outside the box... If your information will be printed directly into user's screen (without any content that needs to be modified in a consecutive order, like a sum or something), simply print from bottom to top.
So, instead of inserting each new block of content to the end of the print space (A += B), add that block to the beginning (A = B+A).
If you'll include the elements as a consecutive ordered list, the DOM can put the numbers for you if you insert each element as a List Item (<li>) inside an Ordered Lists (<ol>).
This way you save space from your database, avoiding unnecesary reversed data.

Dijit/Dojo Inline - Filtering Select - DataStore

I am using an inline filteringselect with datastore, as follows:
I am using ABBR as the identifier and NAME as the value.
The filtering selects and works correctly, but I have two issues.
Firstly, how do I retrieve the ABBR for the selected option NAME?
I have tried various things, including .innerHTML but that only retrieves the selected item name, not the identifier.
Secondly, when using the datastore option, how can I choose the default selected item, for example if it was a scale of 1 to 10 and I wanted 5 as the default selection, how can I do this?
Any ideas and advice would be greatly appreciated.
Mank thanks
dojo.addOnLoad(function() {
// inline store
str = new dojo.data.ItemFileReadStore({data: storeData10})
var itmes;
// for storing the store's items
str.fetch({
onComplete:function(itms){
itmes= itms;
console.log(itms)
}
})
dijit.byId("cmbx1").store = str
dojo.connect(dijit.byId("cmbx1"), 'onChange',function(){
//console.log(arguments);
//get the value u c in screen
var whatvseeinselect = dijit.byId("cmbx1").focusNode.value;
dojo.forEach(itmes, function(itm){
//compare the value u c in screen with store itms. once matched take that item and get the name attr or other attr if u require..
if(whatvseeinselect == str.getValue(itm,"name")){
console.log(str.getValue(itm,"name"));
}
})
})
});
I'm not sure whether this is the correct way.
Hope this helps