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Warning : Failed child context type: Invalid child context 'virtualizedCell.cellKey' of type 'number' supplied to 'CellRenderer', expected 'string'

See original GitHub issue

Please make our job easier by filling this template out to completion. If you’re requesting a feature instead of reporting a bug, please feel free to skip the Environment and Reproducible Demo sections.

Description

Since I upgraded from react-native 0.51 to 0.53, I get this warning in the Adenda: Warning : Failed child context type: Invalid child context ‘virtualizedCell.cellKey’ of type ‘number’ supplied to ‘CellRenderer’, expected ‘string’

Expected Behavior

What action did you perform, and what did you expect to happen? I upgraded from react-native 0.51 to 0.53

Observed Behavior

What actually happened when you performed the above actions? the warning is poping.

If there’s an error message, please paste the full terminal output and error message in this code block: No error, just a warning…

Warning: Failed child context type: Invalid child context virtualizedCell.cellKey of type number supplied to CellRenderer, expected string. in CellRenderer (at VirtualizedList.js:681) in RCTView (at View.js:71) in View (at ScrollView.js:726) in RCTScrollView (at ScrollView.js:820) in ScrollView (at VirtualizedList.js:1009) in VirtualizedList (at FlatList.js:640) in FlatList (at index.js:188) in ReactComp (at index.js:267) in RCTView (at View.js:71) in View (at index.js:375) in RCTView (at View.js:71) in View (at index.js:374) in AgendaView (at Calendar.js:96) in Calendar (created by Connect(Calendar)) in Connect(Calendar) (at Navigation.js:83) in Provider (at Navigation.js:82) in _class2 (at renderApplication.js:35) in RCTView (at View.js:71) in View (at AppContainer.js:102) in RCTView (at View.js:71) in View (at AppContainer.js:122) in AppContainer (at renderApplication.js:34)

Environment

Please run these commands in the project folder and fill in their results:

npm ls react-native-calendars: `-- react-native-calendars@1.17.1
npm ls react-native: `-- react-native@0.53

Also specify:

Phone/emulator/simulator & version:

This is hapenning for both iOS and Android. It seems that react-native is now expecting String keys in ListViews, but not sure how to address this issue.

Issue Analytics

State:
Created 6 years ago
Reactions:8
Comments:11 (2 by maintainers)

Top GitHub Comments

20reactions

donni106commented, Mar 13, 2018

Thx @anti-nerd, this helped me out.

Changed keyExtractor = (item) => item.id; to keyExtractor = (item) => `key-${item.id}`; and the warning disappeared.

14reactions

crim3houndcommented, Mar 11, 2018

Facing a similar issue in RN 0.54.1.

UPDATE: Just fixed the issue by converting the result from my key extractor to a string using the toString() method as follows: _keyExtractor = (item, index) => index.toString();. I hope this helps someone else.

cc: @sylvainbouxin @hardy-android @chrismllr