getListUi returns old list view

Question

I am using following LWC wrapper in aura to get list views:

LWC:

import { LightningElement, wire, track, api } from 'lwc';
import { getListUi } from 'lightning/uiListApi';

export default class WireListView extends LightningElement {
    @api objectApiName;
    @api listViewApiName;
    @wire(getListUi, {
            objectApiName: '$objectApiName',
            listViewApiName: '$listViewApiName'
        })
    listView
    @api get result(){
        return this.listView;
    }
}

Aura:

<aura:handler name="change" value="{!v.myList}" action="{!c.listViewChange}"/>
<DecsOnD:wireListView
                aura:id="wireListView"
                listViewApiName="{!!empty(v.selectedView.NamespacePrefix)
                    ? v.selectedView.NamespacePrefix + '__' + v.selectedView.DeveloperName
                    : v.selectedView.DeveloperName}"
                objectApiName="{!v.selectedObject}"
                result="{!v.myList}"/>

I've got couple of problems:

1. I need to change v.selectedView.DeveloperName couple for times so that actual record propagates. I suspect this due to how @api get reusult works - it returns previous record
2. My change handler fires twice, which is sort of ok, but wondering why - I suspect because I'm passing two attributes?
3. On init getListUi seems to retrieve a list of list views - which would be very useful if I can understand how it works exactly :) ATM I am using SOQL query, but in future I could use this instead.

Answer 1

I need to change v.selectedView.DeveloperName couple for times so that actual record propagates. I suspect this due to how @api get reusult works - it returns previous record

It's caching behavior plus some odd data propagation happening here. You'll want to fire a custom event for your aura component to listen to, and react accordingly. To do this, use a function with a backing property instead of using the listView property you're using now.

_listView;
@wire(getListUi, { objectApiName: '$objectApiName', listViewApiName: '$listViewApiName' })
listView({ error, data }) {
  if(data) {
    const listUpdate = new CustomEvent('listviewupdated', { data: data });
    this.dispatchEvent(listUpdate);
    this._listView = data;
  } else {
    // Choose if you wish to handle or ignore errors
  }
}
@api get result() {
  return this._listView;
}

You could even get clever here and dispatch one of two types of events, depending on if you get the list of list views, or if you get a single list view. This might make your logic in the aura component more legible as a bonus.

My change handler fires twice, which is sort of ok, but wondering why - I suspect because I'm passing two attributes?

Yes, this is expected, normal behavior. It shouldn't harm anything, though you might want to watch out for errors within your component. Notably, if given a choice, make sure you change objectApiName before you change listViewApiName.

On init getListUi seems to retrieve a list of list views - which would be very useful if I can understand how it works exactly :) ATM I am using SOQL query, but in future I could use this instead.

This is explained on the getListUi documentation. Basically, if objectApiName is not null, but listViewApiName is null, you'll get a list of list views. The structure of this is documented at the bottom of the getListUi doc page.