added onload event #180
added onload event #180
Conversation
src/FlashList.tsx
Outdated
| @@ -338,6 +354,7 @@ class FlashList<T> extends React.PureComponent< | |||
| finalRenderAheadOffset={finalDrawDistance} | |||
| renderAheadStep={finalDrawDistance} | |||
| initialRenderIndex={initialScrollIndex || undefined} | |||
| onItemLayout={this.raiseOnLoadEvent} | |||
There was a problem hiding this comment.
I don't 100% follow why raiseOnLoadEvent can be called either from componentDidMount or from ProgressiveListView's onItemLayout - could you please explain it again?
There was a problem hiding this comment.
Let's say if I pass empty data and expect list to render ListEmptyComponent then I check that in did mount and raise the event.
For other cases I listen to onItemLayout of RLV which is raised whenever any item's onLayout is triggered which is a great proxy as this event is raised after an item is rendered.
There was a problem hiding this comment.
Does it mean that if list is not empty, onLayout of any item gets called before componentDidMount?
There was a problem hiding this comment.
It's the other way actually. For FlashList onLayout will come after componentDidMount. There won't be any rendered items when the list mounts.
The check on mount method is only needed if list is empty.
There was a problem hiding this comment.
For FlashList onLayout will come after componentDidMount.
Doesn't it mean that in both cases (empty vs non-empty list) componentDidMount is called first?
There was a problem hiding this comment.
Yes that's true. But for empty list there won't be an onLayout (as there are no items) so I need to check in componentDidMount. I can check if data is empty I can simply raise the event there and then.
There was a problem hiding this comment.
Doesn't it mean that in both cases (empty vs non-empty list) componentDidMount is called first?
I think so, but then this will be false and the event won't be raised.
There was a problem hiding this comment.
@fortmarek that's the right thing to do if you think about it. If someone renders empty list component the load of the component should be considered as the load event. Passing data in the next cycle is an update and you can't know how much time app spent in fetching the data.
As soon as list finishes what's expected out of the first render we should raise onLoadComplete.
There was a problem hiding this comment.
that's the right thing to do if you think about it. If someone renders empty list component the load of the component should be considered as the load event. Passing data in the next cycle is an update and you can't know how much time app spent in fetching the data.
I agree, I was being in support of the current solution 😅
There was a problem hiding this comment.
Oh I missed the point I think :P
Description
Added
onLoadEventto report once items have been rendered.Checklist