react-infinite-feed

Infinite feed with up or down scroll direction

Instalation

npm install --save react-infinite-feed

Usage

This component helps to implement infinite scroll. It takes loadOffset property and when user scrolled to that point it handles onReachOffset function, which can be used to load additional data to the feed.

By default scroll works from the top to the bottom (like socials feeds e.g. facebook or instagram). If you set property isScrollUp the component will scroll from the bottom to the top (like messengers e.g. telegram).

import React, { PureComponent } from 'react'
import Feed from 'react-infinite-feed'

import Loader from './Loader/Loader'
import Message from './Message/Message'


export default class Chat extends PureComponent {

  state = {
    shouldScrollUp: false,
    shouldScrollDown: false,
  }

  componentDidUpdate({ chatMessages: oldChatMessages }) {
    const { chatMessages } = this.props

    // these steps are necessary only if your scroll direction is up 
    const isMessagesUpdated = (
      !oldChatMessages.length
      || chatMessages.some(({ id }, index) => !oldChatMessages[index] || oldChatMessages[index].id !== id)
    )

    if (!oldChatMessages.length) {
      this.setState({
        shouldScrollDown: true,
      })
    }
    else if (isMessagesUpdated) {
      this.setState({
        shouldScrollUp: true,
      })
    }
    else {
      this.setState({
        shouldScrollUp: false,
        shouldScrollDown: false,
      })
    }
  }

  fetchMoreMessages = () => {
    // Some actions to fetch more messages to 'chatMessages' property
  }

  render() {
    const { shouldScrollUp, shouldScrollDown } = this.state
    const { chatMessages, loadOffset, isLoadedChatMessages } = this.props

    return (
      <Feed
        isScrollUp
        onReachOffset={this.fetchMoreMessages}
        {...{ loadOffset, shouldScrollUp, shouldScrollDown }}
      >
        {
          isLoadedChatMessages
            ? chatMessages.map(({ id, message, author }) => (
              <Message key={id} {...{ id, message, author }} />
            ))
            : <Loader />
        }
      </Feed>
    )
  }
}

Examples

Scroll up feed demo

Boilerplate with this component