在 ReactJs 中加载更多实现

Question

I am trying to implement load more button for my small project GiF generator. First I thought of appending next set of 20 response at the bottom, but failed to do. Next, I thought of implementing loading the next set of 20 results by simply removing the current one. I tried to trigger a method on click of button, but I failed to do so. Its updating the state on second click of load more and then never updating it again. Please help me find what I am missing, I have started learning React yesterday itself.

import React, { useEffect, useState } from 'react';
import './App.css';
import Gif from './Gif/Gif';

const App = () => {
  const API_KEY = 'LIVDSRZULELA';

  const [gifs, setGif] = useState([]);
  const [search, setSearch] = useState('');
  const [query, setQuery] = useState('random');
  const [limit, setLimit] = useState(20);
  const [pos, setPos] = useState(1);

  useEffect(() => {
    getGif();
  }, [query])

  const getGif = async () => {
    const response = await fetch(`https://api.tenor.com/v1/search?q=${query}&key=${API_KEY}&limit=${limit}&pos=${pos}`);
    const data = await response.json();
    setGif(data.results);
    console.log(data.results)
  }

  const updateSearch = e => {
    setSearch(e.target.value);
  }

  const getSearch = e => {
    e.preventDefault();
    setQuery(search);
    setSearch('');
  }

  const reload = () => {
    setQuery('random')
  }

  const loadMore = () => { // this is where I want my Pos to update with 21 on first click 41 on second and so on
    let temp = limit + 1 + pos;
    setPos(temp);
    setQuery(query);
  }

  return (
    <div className="App">
      <header className="header">
        <h1 className="title" onClick={reload}>React GiF Finder</h1>
        <form onSubmit={getSearch} className="search-from">
          <input className="search-bar" type="text" value={search}
            onChange={updateSearch} placeholder="type here..." />
          <button className="search-button" type="submit">Search</button>
        </form>
        <p>showing results for <span>{query}</span></p>
      </header>
      <div className="gif">
        {gifs.map(gif => (
          <Gif
            img={gif.media[0].tinygif.url}
            key={gif.id}
          />
        ))}
      </div>
      <button className="load-button" onClick={loadMore}>Load more</button>
    </div>
  );
}

export default App;

Please, help me find, what I am doing wrong, As I know the moment I will update setQuery useEffect should be called with new input but its not happening.

Answer 1

Maybe try something like this:

  // Fetch gifs initially and then any time
  // the search changes.
  useEffect(() => {
    getGif().then(all => setGifs(all);
  }, [query])

  // If called without a position index, always load the
  // initial list of items.
  const getGif = async (position = 1) => {
    const response = await fetch(`https://api.tenor.com/v1/search?q=${query}&key=${API_KEY}&limit=${limit}&pos=${position}`);
    const data = await response.json();
    return data.results;
  }


  // Append new gifs to existing list
  const loadMore = () => {
    let position = limit + 1 + pos;
    setPos(position);
    getGif(position).then(more => setGifs([...gifs, ...more]);
  }

  const getSearch = e => {
    e.preventDefault();
    setQuery(search);
    setSearch('');
  }

  const updateSearch = e => setSearch(e.target.value);

  const reload = () => setQuery('random');

Basically, have the getGifs method be a bit more generic and then if loadMore is called, get the next list of gifs from getGift and append to existing list of gifs.