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More than 9 items in the data causes the Carousel to re-render all the items indefinitely

See original GitHub issue

Is this a bug report or a feature request?

Bug report

Have you read the guidelines regarding bug report?

Yes.

Have you read the documentation in its entirety?

Yes.

Have you made sure that your issue hasn’t already been reported/solved?

Yes.

Is the bug specific to iOS or Android? Or can it be reproduced on both platforms?

I only have an iOS device so I am not sure.

Is the bug reproductible in a production environment (not a debug one)?

Yes.

Have you made sure that it wasn’t a React Native bug?

Yes

Have you been able to reproduce the bug in the provided example?

Yes

Environment

Environment: React: 16.2.0 React native: 0.49.0 react-native-snap-carousel: 3.7.0

Target Platform: iOS (8.0)

Steps to Reproduce

Render a carousel with 9 items and console.log when the renderItem function is called.
See that it only renders the items once, as it should.
Then add a 10th item to the data array, and see how the renderItem methods is called indefinitely on every item.

<Carousel
                            data={[{a: '2'}, {a: '44'}, {a: '21'}, {a: '2'}, {a: '33'}, {a: '11'}, {a: '6'}, {a: '77'}, {a: '99'}, {a: '01'}]}
                            renderItem={({item, index}) => {
                                console.log('== RENDER ITEM == ' + index);
                                return <View />
                            }}
                            sliderWidth={Window.width}
                            itemWidth={Window.width}
                        />

Expected Behavior

I thought that I would only see render calls to the items that are visible and the rest would only be called ONCE they are visible.

Actual Behavior

The carousel constantly rerenders the items non stop.

Issue Analytics

State:
Created 5 years ago
Reactions:4
Comments:21 (4 by maintainers)

Top GitHub Comments

1reaction

UdaraJaycommented, Jul 25, 2018

I had the same issue and at-least in my case it turned out to be the case the issue was the content in the carousel component - the items were re-rendering continuously… which slowed down the carousel and made it very glitchy.

So I’d suggest taking a second look at the content you put in the carousel.

1reaction

sridhardcommented, Jul 24, 2018

This is same as #349 …Please check