Sometimes it renders blank rows

[revh]

Hi,

i'm trying to use this library because i have a large list so.. at first glance i was perfect and really fast, but when i scroll at the bottom of the list i see some blank rows.

this is my code:

<LargeList
  style={{ flex: 1 }}
  numberOfRowsInSection={section => this.sectionsInSections[section].info.length}
  numberOfSections={() => Object.keys(this.sectionsInSections).length}
  heightForCell={() => this.ITEM_HEIGHT}
  heightForSection={() => this.ITEM_HEIGHT}
  renderCell={this.renderItem2}
  renderSection={this.renderSectionHeader2}
  renderItemSeparator={() => <ListSeparator />}
/>

renderItem2 and renderSectionHeader2 only returns a and this.ITEM_HEIGHT is 40.

Don't know if this is important but LargeList is wrapped inside this component https://github.com/skv-headless/react-native-scrollable-tab-view

Thank you

[bolan9999]

Let me see your screen snapshot， plz

[bolan9999]

Is is the same with issue #66 ?

[bolan9999]

You can set numberOfSectionPoolSize or numberOfCellPoolSize to solve your problem

[revh]

Thank you, as you can see in the screenshoot within 2 scroll a section appear and disappear,

It seems that setting numberOfSectionPoolSize to the number of my section do the job on the simulator but on an iPhoneX scrolling too fast down and up it leads to weird things like the most top section doesn't have rows, multiple rows with the same text and app crash :(

i tried also with numberOfSectionPoolSize to the number of rows in total

Thanks

[bolan9999]

try to set numberOfSectionPoolSize to 15

[revh]

Ok is better, but scrolling down and up the app crash with this error:

undefined is not an object (evaluating 'e.sectionsInSections[t].info')

it seems that numberOfRowsInSection or renderItem/renderSection are passing a not valid section index?

thank you

[bolan9999]

Do you change your data source ? If you did, you must call reloadData. see the docs,plz

[revh]

the data source is not changed, if i add this code, to debug the problem, it yields -1 some times

numberOfRowsInSection={section =>
                        this.sectionsInSections[section]
                            ? this.sectionsInSections[section].info.length
                            : alert(section)
                    }

[bolan9999]

Maybe it is a bug.

I'll fix it right row. You can return 0 if section === -1 for this version.

[revh]

Thank you @bolan9999 !

i want also to report that if you scroll programmatically using

this.list.scrollToIndexPath(this.list.bottomIndexPath, false)

and then

this.list.scrollToIndex(this.list.topIndexPath, false)
(i want to implement an alphabetic index on the side)

it leads to some not updated sections or blank rows

[bolan9999]

I have tried, and there is no problem on scrollToIndexPath. How do you operate？ More information need! Scrolling must action after LargeList finish initializing.

[bolan9999]

No response for 4 days,closed