React-Native Flatlist is re-rendering images whenever state change

Question

The setup!
I have dynamic loading images in a chat - like interface with messages that are just text, or messages that are images and text. Currently I have it working where it loading images from an external url that is stored in firebase storage with the meta data CacheControl set to allow image cache.

I am displaying the image through a standard react-native library Image in a pretty standard flatlist. The one thing that I am doing that is weird is conditionally adding a component based on the state in the flatlist data. EXAMPLE:

    ImageOrViewMessages = (props) => {   
                if(item != null && item.image != ''){               
                    return (
                        <View>
                            <Image source={{uri: item.image, cache: "force-cache"}} style={{display: 'flex', height: 300, flex: 1, padding: 5}} />
                        </View>
                    )
                } else {
                    return(
                        <View style={{display: 'none'}}></View>
                    )
                }
            }

Here is my flatlist:

    <FlatList
        data={this.props.unsent_messages.length > 0 && this.props.chat != '' ? this.props.unsent_messages.concat(this.props.messages) : this.props.messages}
        renderItem={({item}) => {
            var align_text = "flex-end"
            var background_color = colors.main_color_light;
            var text_color = "white"
            var stamp = "none"
            if(item.username.toLowerCase() != this.props.displayName.toLowerCase()){
                //do something differ
                align_text = "flex-start"
                background_color = colors.main_color_dark;
                text_color = "white"
                stamp = "flex"
            }
            ImageOrViewMessages = (props) => {   
                if(item != null && item.image != ''){               
                    return (
                        <View>
                            <Image source={{uri: item.image, cache: "force-cache"}} style={{display: 'flex', height: 300, flex: 1, padding: 5}} />
                        </View>
                    )
                } else {
                    return(
                        <View style={{display: 'none'}}></View>
                    )
                }
            }


            return(
                <View style={{padding: 5, minHeight: 70, alignItems: align_text, justifyContent: "center"}}>
                    <View style={{opacity: item.id.toString().includes("Unset") ? .3 : 1, backgroundColor: background_color, padding: 5, borderWidth: 0, borderColor: colors.border_color,borderRadius: 8 , width: (Dimensions.get('window').width / 2) - 10, alignSelf: align_text}}>
                        <Text style={{fontFamily: "MarkerFelt-Thin", color: text_color, fontSize: 16, textAlign: "left", flex: 1}}>{item.message}</Text>
                        {/* <Text style={{display: stamp, fontFamily: "MarkerFelt-Thin", color: colors.background_color, fontSize: 14, textAlign: "right", flex: 1}}>{item.username}</Text> */}
                        <ImageOrViewMessages />
                    </View>
                </View>
            )}
            }
            keyExtractor={item => item.image != '' ? item.image : item.id.toString()}   
            style={{display: 'flex', flex: 1, borderTopLeftRadius: 25, borderTopRightRadius: 25}}    
            ref={ref => this.flatList = ref}
            inverted={true}  
        />

The Issue!
The images render perfectly fine, but every single time they are having to download from my server, rather than storing in cache. The things I have tried are making sure my metadeta on the uploaded image is set correctly. Forcing the cache through the Image property "Cache". I have made sure I have a unique key set for each item in the list including images through the key extractor. I am also able to cache the image on my main page without any issue (when it is no longer in a flatlist)

Answer 1

Yeah, it will be re-render image from server everytime. You need to cache image in default application or device memory. Best way is the FastImage for lazyloading.

Replace your image load with below one:

 <FastImage
    style={styles.image}
    source={{
      uri: YOUR_IMAGE_URL,
      priority: FastImage.priority.normal,
    }}
    resizeMode={FastImage.resizeMode.contain}
  />

Don't forgot to import FastImage.

import FastImage from 'react-native-fast-image'