= array(); } $post['classname'] = 'post'; } function comment_format(&$post) { global $conf, $uid, $gid, $forumlist; if (empty($post)) return; $forum = $post['fid'] ? forum_read($post['fid']) : ''; $thread = well_thread_read_cache($post['tid']); if ($thread) { //$post['fid'] = $thread['fid']; $post['closed'] = $thread['closed']; $post['subject'] = $thread['subject']; $post['url'] = $thread['url']; } else { $post['closed'] = 0; $post['subject'] = lang('thread_not_exists'); $post['url'] = ''; } $post['create_date_fmt'] = humandate($post['create_date']); //$post['message'] = stripslashes(htmlspecialchars_decode($post['message'])); $user = user_read_cache($post['uid']); $post['username'] = array_value($user, 'username'); $post['user_avatar_url'] = array_value($user, 'avatar_url'); $post['user'] = $user ? user_safe_info($user) : user_guest(); isset($post['floor']) || $post['floor'] = 0; // 权限判断 $post['allowupdate'] = 2 == array_value($forum, 'comment', 0) && ($uid == $post['uid'] || forum_access_mod($post['fid'], $gid, 'allowupdate')); $post['allowdelete'] = group_access($gid, 'allowuserdelete') && $uid == $post['uid'] || forum_access_mod($post['fid'], $gid, 'allowdelete'); $post['user_url'] = url('user-' . $post['uid'] . ($post['uid'] ? '' : '-' . $post['pid'])); if ($post['files'] > 0) { list($attachlist, $imagelist, $filelist) = well_attach_find_by_pid($post['pid']); // 使用图床 评论使用图床,mysql会过多,写死链接到内容是减轻mysql的过多的方法 if (2 == $conf['attach_on']) { foreach ($imagelist as $key => $attach) { $url = $conf['upload_url'] . 'website_attach/' . $attach['filename']; // 替换成图床 $post['message'] = FALSE !== strpos($post['message'], $url) && $attach['image_url'] ? str_replace($url, $attach['image_url'], $post['message']) : $post['message']; } } $post['filelist'] = $filelist; } else { $post['filelist'] = array(); } $post['classname'] = 'post'; } function comment_format_message(&$val) { global $conf; if (empty($val)) return; // 使用云储存 if (1 == $conf['attach_on'] && 1 == $val['attach_on']) { $val['message'] = str_replace('="upload/', '="' . file_path($val['attach_on']), $val['message']); } elseif (2 == $conf['attach_on'] && 2 == $val['attach_on']) { // 使用图床 list($attachlist, $imagelist, $filelist) = well_attach_find_by_tid($val['tid']); foreach ($imagelist as $key => $attach) { $url = $conf['upload_url'] . 'website_attach/' . $attach['filename']; // 替换成图床 $val['message'] = FALSE !== strpos($val['message'], $url) && $attach['image_url'] ? str_replace($url, $attach['image_url'], $val['message']) : $val['message']; } } else { $val['message'] = str_replace('="upload/', '="' . file_path($val['attach_on']), $val['message']); } //$val['message'] = stripslashes(htmlspecialchars_decode($val['message'])); } // 把内容中使用了云储存的附件链接替换掉 function comment_message_replace_url($pid, $message) { global $conf; if (0 == $conf['attach_on']) { $message = FALSE !== strpos($message, '="../upload/') ? str_replace('="../upload/', '="upload/', $message) : $message; $message = FALSE !== strpos($message, '="/upload/') ? str_replace('="/upload/', '="upload/', $message) : $message; } elseif (1 == $conf['attach_on']) { // 使用云储存 $message = str_replace('="' . $conf['cloud_url'] . 'upload/', '="upload/', $message); } elseif (2 == $conf['attach_on']) { // 使用图床 评论使用图床,mysql会过多,写死链接到内容是减轻mysql的过多的方法 list($attachlist, $imagelist, $filelist) = well_attach_find_by_pid($pid); foreach ($imagelist as $key => $attach) { $url = $conf['upload_url'] . 'website_attach/' . $attach['filename']; // 替换回相对链接 $message = $attach['image_url'] && FALSE !== strpos($message, $attach['image_url']) ? str_replace($attach['image_url'], $url, $message) : $message; } } return $message; } function comment_filter($val) { unset($val['userip']); return $val; } function comment_highlight_keyword($str, $k) { $r = str_ireplace($k, '' . $k . '', $str); return $r; } // //
function comment_message_format(&$s) { if (xn_strlen($s) < 100) return; $s = preg_replace('#.*?
#is', '', $s); $s = str_ireplace(array('
', '
', '
', '

', '', '', '', '' . ''), "\r\n", $s); $s = str_ireplace(array(' '), " ", $s); $s = strip_tags($s); $s = preg_replace('#[\r\n]+#', "\n", $s); $s = xn_substr(trim($s), 0, 100); $s = str_replace("\n", '
', $s); } // 对内容进行引用 function comment_quote($quotepid) { $quotepost = comment_read($quotepid); if (empty($quotepost)) return ''; $uid = $quotepost['uid']; $s = $quotepost['message']; $s = comment_brief($s, 100); $userhref = url('user-' . $uid); $user = user_read_cache($uid); $r = '
' . $user['username'] . ' ' . $s . '
'; return $r; } // 获取内容的简介 0: html, 1: txt; 2: markdown; 3: ubb function comment_brief($s, $len = 100) { $s = strip_tags($s); $s = htmlspecialchars($s); $more = xn_strlen($s) > $len ? ' ... ' : ''; $s = xn_substr($s, 0, $len) . $more; return $s; } ?>javascript - How to filter an array onClick in React - Stack Overflow
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javascript - How to filter an array onClick in React - Stack Overflow

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I am trying to filter an array of coffee based on its origin via a button click in React. Right now, whenever a button is clicked the array goes to 0 instead of the desired result of however many items contain the origin clicked. Thanks for your help. Feel free to critique my code as well - I am just beginning!


class Coffee extends React.Component {

  constructor() {
    super();
    this.state = { coffees: [
  {
    name: 'Banko',
    origin: 'Ethiopia',
    price: 16
  },
  {
    name: 'Pueblo',
    origin: 'Costa Rica',
    price: 14
  },
  {
    name: 'Don Pablo',
    origin: 'Columbia',
    price: 13
  },
  {
    name: 'Hava Lama',
    origin: 'Columbia',
    price: 15
  },
  {
    name: 'Guillermo Salva',
    origin: 'Ethiopia',
    price: 19
  },
  {
    name: 'Salla Rosa',
    origin: 'Kenya',
    price: 20
  },
  {
    name: 'Santor Gustavio',
    origin: 'Panama',
    price: 25
      }
     ] 
    }
   }

  handleClick = event => {
    const byOrigin = event.target.value

    const filterCoffee = this.state.coffees.filter(coffee => coffee[origin] === [byOrigin])
    this.setState({coffees: filterCoffee})

  }


  render() {

    const renderAll = this.state.coffees.map(coffee => <li key={Date.now()}>{coffee.name}</li>)


    return (

      <div>
        <button value='all' onClick={this.handleClick}>All</button>
        <button value='Ethiopia' onClick={this.handleClick}>Ethiopia</button>
        <button value='Costa Rica' onClick={this.handleClick}>Costa Rica</button>
        <button value='Kenya' onClick={this.handleClick}>Kenya</button>
        <button value='Columbia' onClick={this.handleClick}>Columbia</button>
        <button value='Panama' onClick={this.handleClick}>Panama</button>


        <p>Coffee: {renderAll}</p>
        <p>{this.state.coffees.length}</p>

      </div>

    )
  }
}

ReactDOM.render(<Coffee />, document.getElementById('root'))

I am trying to filter an array of coffee based on its origin via a button click in React. Right now, whenever a button is clicked the array goes to 0 instead of the desired result of however many items contain the origin clicked. Thanks for your help. Feel free to critique my code as well - I am just beginning!


class Coffee extends React.Component {

  constructor() {
    super();
    this.state = { coffees: [
  {
    name: 'Banko',
    origin: 'Ethiopia',
    price: 16
  },
  {
    name: 'Pueblo',
    origin: 'Costa Rica',
    price: 14
  },
  {
    name: 'Don Pablo',
    origin: 'Columbia',
    price: 13
  },
  {
    name: 'Hava Lama',
    origin: 'Columbia',
    price: 15
  },
  {
    name: 'Guillermo Salva',
    origin: 'Ethiopia',
    price: 19
  },
  {
    name: 'Salla Rosa',
    origin: 'Kenya',
    price: 20
  },
  {
    name: 'Santor Gustavio',
    origin: 'Panama',
    price: 25
      }
     ] 
    }
   }

  handleClick = event => {
    const byOrigin = event.target.value

    const filterCoffee = this.state.coffees.filter(coffee => coffee[origin] === [byOrigin])
    this.setState({coffees: filterCoffee})

  }


  render() {

    const renderAll = this.state.coffees.map(coffee => <li key={Date.now()}>{coffee.name}</li>)


    return (

      <div>
        <button value='all' onClick={this.handleClick}>All</button>
        <button value='Ethiopia' onClick={this.handleClick}>Ethiopia</button>
        <button value='Costa Rica' onClick={this.handleClick}>Costa Rica</button>
        <button value='Kenya' onClick={this.handleClick}>Kenya</button>
        <button value='Columbia' onClick={this.handleClick}>Columbia</button>
        <button value='Panama' onClick={this.handleClick}>Panama</button>


        <p>Coffee: {renderAll}</p>
        <p>{this.state.coffees.length}</p>

      </div>

    )
  }
}

ReactDOM.render(<Coffee />, document.getElementById('root'))

Share Improve this question asked Dec 2, 2019 at 4:08 TrevPenningtonTrevPennington 4751 gold badge5 silver badges21 bronze badges 5
  • verify this equality check coffee[origin] === [byOrigin]. – Nikhil Koul Commented Dec 2, 2019 at 4:13
  • try this check like this this.state.coffees.filter(coffee => coffee[origin] === byOrigin) – Nouman Janjua Commented Dec 2, 2019 at 4:15
  • Try change to .filter(coffee => coffee.origin === byOrigin) – thortsx Commented Dec 2, 2019 at 4:15
  • One more thing, once this array is filtered by a origin, than you will not be able to get data for other origins – Nouman Janjua Commented Dec 2, 2019 at 4:20
  • Hi Trev, check my solution and let me know if that helps. – ravibagul91 Commented Dec 2, 2019 at 4:36
Add a ment  | 

3 Answers 3

Reset to default 2

You can check like this, please try this.

this.state.coffees.filter(coffee => coffee['origin'] === byOrigin)

Optimized way

const buttons = [
  { name: "All", value: "All" },
  { name: "Ethiopia", value: "Ethiopia" },
  { name: "Costa Rica", value: "Costa Rica" },
  { name: "Kenya", value: "Kenya" },
  { name: "Columbia", value: "Columbia" },
  { name: "Panama", value: "Panama" }
];

define button in loop for optimization

        {buttons.map(({ name, value }) => (
          <button
            key={name}
            value={value}
            onClick={this.handleClick.bind(this, name)}
          >
            {name}
          </button>
        ))}

Complete code

const buttons = [
  { name: "All", value: "All" },
  { name: "Ethiopia", value: "Ethiopia" },
  { name: "Costa Rica", value: "Costa Rica" },
  { name: "Kenya", value: "Kenya" },
  { name: "Columbia", value: "Columbia" },
  { name: "Panama", value: "Panama" }
];
class Coffee extends React.Component {
  constructor() {
    super();
    this.state = {
      coffees: [
        {
          name: "Banko",
          origin: "Ethiopia",
          price: 16
        },
        {
          name: "Pueblo",
          origin: "Costa Rica",
          price: 14
        },
        {
          name: "Don Pablo",
          origin: "Columbia",
          price: 13
        },
        {
          name: "Hava Lama",
          origin: "Columbia",
          price: 15
        },
        {
          name: "Guillermo Salva",
          origin: "Ethiopia",
          price: 19
        },
        {
          name: "Salla Rosa",
          origin: "Kenya",
          price: 20
        },
        {
          name: "Santor Gustavio",
          origin: "Panama",
          price: 25
        }
      ],
      filterCoffee: []
    };
  }

  ponentDidMount() {
    this.setState({
      filterCoffee: this.state.coffees
    });
  }

  handleClick = name => {
    let filterCoffee = [];
    if (name === "All") {
      filterCoffee = this.state.coffees;
    } else {
      filterCoffee = this.state.coffees.filter(
        coffee => coffee.origin === name
      );
    }

    this.setState({ filterCoffee });
  };

  render() {
    const renderAll = this.state.filterCoffee.map(coffee => (
      <li key={coffee.name}>{coffee.name}</li>
    ));
    return (
      <div>
        {buttons.map(({ name, value }) => (
          <button
            key={name}
            value={value}
            onClick={this.handleClick.bind(this, name)}
          >
            {name}
          </button>
        ))}

        <p>Coffee: {renderAll}</p>
        <h2>{this.state.filterCoffee.length}</h2>
      </div>
    );
  }
}

You should have a separate array of original coffees. On ponent mount, you must copy your original array into another array and use that array further.

this.state = {
    coffees: [{
            name: 'Banko',
            origin: 'Ethiopia',
            price: 16
        },
        {
            name: 'Pueblo',
            origin: 'Costa Rica',
            price: 14
        },
        {
            name: 'Don Pablo',
            origin: 'Columbia',
            price: 13
        },
        {
            name: 'Hava Lama',
            origin: 'Columbia',
            price: 15
        },
        {
            name: 'Guillermo Salva',
            origin: 'Ethiopia',
            price: 19
        },
        {
            name: 'Salla Rosa',
            origin: 'Kenya',
            price: 20
        },
        {
            name: 'Santor Gustavio',
            origin: 'Panama',
            price: 25
        }
    ],
    filterCoffee: []  //create another array
}

On ponent mount copy original array to a temparary array

ponentDidMount(){
   this.setState({
     filterCoffee: this.state.coffees
   })
}

Now use filterCoffee to render

const renderAll = this.state.filterCoffee.map(coffee => <li key={coffee.name}>{coffee.name}</li>)

Finally on click you must check the condition when you click on all button,

handleClick = event => {
    const byOrigin = event.target.value
    let filterCoffee = []
    if(event.target.value === 'all'){
      //If clicked on all button copy the original array as it is
      filterCoffee = this.state.coffees   
    } else{
      // If clicked on any other button filter the original array based on value
      filterCoffee = this.state.coffees.filter(coffee => coffee.origin === byOrigin)
    } 
    this.setState({filterCoffee})
}

Demo

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