React native: remove item from ListView

Question

I'm using React Native (0.12.0) on Android and have a ListView component on my page. I want to be able to remove items from the list.

This ListView looks like this:

<ListView
    dataSource={this.state.dataSource}
    renderRow={this._renderStory}
    onEndReached={this._getStories}
    />

The rowHasChanged method looks like this.

this.state = {
    dataSource: new ListView.DataSource({
        rowHasChanged: (row1, row2) => {
            return row1 !== row2;
        },
    }),
    loaded: false,
};

All of that works just fine.

Now, to remove an item I have this code:

var indexOfItem = this._data.findIndex((item) => item.id === story.id);
this._data.splice(indexOfItem, 1);

this.setState({
    dataSource: this.state.dataSource.cloneWithRows(this._data),
});

I can confirm that the item is being removed from this._data. this.state.dataSource._cachedRowCount is reduced by one as it should be. The state is being updated and a render cycle triggered. But the item isn't removed from the page. What's more, if I put a console log in this._renderStory(), the only thing happening is it renders a new row at the bottom of the list.

Am I missing something? Is there another step I need to do?

A similar question was asked here but he never got an answer about removing a row. How to add/Delete item into ListView?

All the other examples I've seen around the place lack an example of removing an item.

UPDATE: Thanks, it required passing a clone of the array AND setting a key (sorry can only accept one answer). But this meant the whole list was being rendered. In the end I just set a 'removed' property on the items, tested for that property changing and returned null in the render method if an item was flagged as remove, this was faster than re-rendering all items.

Answer 1

<ListView
  key={this._data}
  dataSource={this.state.dataSource}
  renderRow={this._renderStory}
  onEndReached={this._getStories}
/>

Set the key of the ListView with this._data. If you have an Key/ID array of rows, use it like key={this._data.IDArray}.

See ListView removing wrong row on dataSource update for more details.

Answer 2

In order for the list to update, you need to pass to it a duplicate of the array, not the same array. So in your case, something like this:

this.setState({
  dataSource: state.dataSource.cloneWithRows(this._data.slice(0))
});