如何从 fetch 中获取 uri？

Question

I want to cache images in the app, so they can load faster. The tutorial I found used FileSystem from Expo, but I'm not using expo, so I found react-native-file-access instead. After mounting, the code should check if the image exists, if not, download the image. I've tried but I can't seem to make it work.

import React, {Component} from 'react';
import {Image} from 'react-native';
import shorthash from 'shorthash';
import {Dirs, FileSystem} from 'react-native-file-access';

export default class CacheImage extends Component {
  state = {
    source: null,
  };

  componentDidMount = async () => {
    const {uri} = this.props;
    const name = shorthash.unique(uri);
    const path = `${Dirs.CacheDir}/${name}`;

    const image = await FileSystem.exists(path);
    if (image.exists) {
      this.setState({
        source: {
          uri: image.uri,
        },
      });
      return;
    }

    /* Download image if one doesn't exist */
    const newImage = await FileSystem.fetch(uri, {path: path})
      .then(response => {
        JSON.stringify(response);
      })
      .then(data => data);

    this.setState({
      source: {
        uri: newImage.uri,
      },
    });
    console.log('URI: ', this.state.source);
  };

  render() {
    return <Image style={this.props.style} source={this.state.source} />;
  }
}

Answer 1

the problem come from here

const newImage = await FileSystem.fetch(uri, {path: path})
      .then(response => {
        JSON.stringify(response);
      })
      .then(data => data);

you forget to return when use {}

const newImage = await FileSystem.fetch(uri, {path: path})
      .then(response => {
        return JSON.stringify(response);
      })
      .then(data => data);

Answer 2

I returned the response without the JSON.stringify() .

const newImage = await FileSystem.fetch(uri, {path: path})
      .then(response => {
        return response;
      });

this.setState({
      source: {
        uri: newImage.url,
      },
    });

And I also removed the second .then() because I still get the url without adding it.