Infinite scroll upward direction ionic 3

Ionic Framework ionic-v3
1

How can I use infinite scroll to load more data in reverse direction? I want to load data on scroll up instead of scroll bottom. I’m developing chatting app so i need chat style upward infinite scrolling. thanks,

2

what do you mean?you mean to say that if msg is send then it should go to upward direction.is it right or not?

3

thanks you reply:
I want when I open chat window, it will loading last message and then when I scroll top, it will appear message old.

  • the same: WhatsApp, zalo, message
4

I done by “infinite scroll”
html:
<ion-infinite-scroll (ionInfinite)="$event.waitFor(doInfinite())" threshold=“10px” position=“top”>


-> app.ts [provider]

getMess(id1, id2, numberLimit) {
var user = this.db.collection(‘chats’).doc(this.util.getChatId(id1, id2)).collection(‘chats’);
var firstMess = user.ref
.orderBy(‘date’)
.limit(numberLimit)
return firstMess.get();
}
-> chats.ts

doInfinite(): Promise {
return new Promise((resolve) => {
console.log(resolve);
setTimeout(() => {
var userNext = 10;
this.limitMess += userNext;
this.appProvider.getMess(this.user[‘base64’], this.receiver[‘base64’], this.limitMess).then(x => {
var next = this.db.collection(‘chats’).doc(this.util.getChatId(this.user[‘base64’], this.receiver[‘base64’])).collection(‘chats’).ref
.orderBy(‘date’)
.startAfter(this.lastVisible)
.limit(userNext);
next.get().then(a => {
a.forEach(b => {
this.msgList.push(b.data());
console.log(b.data());
})
})
this.lastVisible = x.docs[x.docs.length - 1];
})
resolve();
}, 500);
})
}
and
ionViewWillEnter() {

this.itemsCollection = this.db.collection<any>('chats');
this.itemsCollection.doc(this.util.getChatId(this.user['base64'], this.receiver['base64'])).collection("chats", 
ref => ref.orderBy('date')).snapshotChanges().subscribe(data => {
  this.msgList = [];
  data.forEach(doc => {
    var chat = doc.payload.doc.data();
    chat['id'] = doc.payload.doc.id;
    this.msgList.push(chat);
  })
})

=> can’t show last message and loading message old orderby(time). can you help me.
Thanks