#javascript #html #firebase #firebase-realtime-database
#javascript #HTML #firebase #firebase-база данных в реальном времени
Вопрос:
Я хочу удалить данные на своем веб-сайте с помощью кнопки удаления. Данные отображаются в виде «#table_body» с помощью кнопки, созданной в javascript. Моя идея здесь заключается в том, что под каждой строкой данных есть кнопка удаления. Моя проблема заключается в том, как удалить данные на основе уникального идентификатора / ссылочного идентификатора, нажав кнопку удалить.
Я попытался присвоить имя «.child(‘123’).remove();» вместо «.child(key).remove();» и это работает. однако он удаляет только данные, основанные на идентификаторе 123. Я хочу, чтобы он удалил данные с уникальным идентификатором. Вот код Javascript: 
var rootRef = firebase.database().ref().child("User");
rootRef.on("child_added", snap => {
var name = snap.child("name").val();
var add = snap.child("address").val();
var contact = snap.child("contact").val();
$("#table_body").append("<tr><td>" name "</td><td>" add "</td><td>" contact "</td><td>");
$("#table_body").append('<button id="1" onClick="reply_click(this.id)">Delete</button></td></tr>');
});
function reply_click(clicked_id){
firebase.database().ref("User").child(key).remove();
} <!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<link rel="apple-touch-icon" sizes="76x76" href="../assets/img/apple-icon.png">
<link rel="icon" type="image/png" href="../assets/img/favicon.png">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
<title>
Happy Paws
</title>
<meta content='width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0, shrink-to-fit=no' name='viewport' />
<!-- Fonts and icons -->
<link rel="stylesheet" type="text/css" href="https://fonts.googleapis.com/css?family=Roboto:300,400,500,700|Roboto Slab:400,700|Material Icons" />
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/font-awesome/latest/css/font-awesome.min.css">
<!-- CSS Files -->
<link href="../assets/css/material-dashboard.css?v=2.1.0" rel="stylesheet" />
<!-- CSS Just for demo purpose, don't include it in your project -->
<link href="../assets/demo/demo.css" rel="stylesheet" />
</head>
<div class="wrapper ">
<div class="sidebar" data-color="green" data-background-color="black" data-image="../assets/img/sidebar-2.jpg">
<!--
Tip 1: You can change the color of the sidebar using: data-color="purple | azure | green | orange | danger"
Tip 2: you can also add an image using data-image tag
-->
<div class="logo">
<a class="simple-text logo-normal">
HAPPY PAWS
</a>
</div>
<div class="sidebar-wrapper">
<ul class="nav">
<li class="nav-item active ">
<a class="nav-link" href="./dashboard.html">
<i class="material-icons">dashboard</i>
<p>Dashboard</p>
</a>
</li>
<li class="nav-item ">
<a class="nav-link" href="./user.html">
<i class="material-icons">person</i>
<p>Account</p>
</a>
</li>
<li class="nav-item ">
<a class="nav-link" href="./tables.html">
<i class="material-icons">content_paste</i>
<p>User List</p>
</a>
</li>
<li class="nav-item dropdown">
<a class="nav-link" href="javscript:void(0)" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<i class="material-icons">library_books</i>
<span class="notification">Pet Article</span>
<p class="d-lg-none d-md-block">
Some Actions
</p>
</a>
<div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbarDropdownMenuLink">
<a class="dropdown-item" href="./typography.html"><p style="color:green;">Articles</p></a>
<a class="dropdown-item" href="./add-article.html"><p style="color:green;">Add Article</p></a>
</li>
<li class="nav-item dropdown">
<a class="nav-link" href="javscript:void(0)" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<i class="material-icons">shopping_cart</i>
<span class="notification">Products</span>
<p class="d-lg-none d-md-block">
Some Actions
</p>
</a>
<div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbarDropdownMenuLink">
<a class="dropdown-item" href="./accessories.html"><p style="color:green;">Accessories</p></a>
<a class="dropdown-item" href="./clothes.html"><p style="color:green;">Clothes</p></a>
<a class="dropdown-item" href="./food.html"><p style="color:green;">Food</p></a>
<a class="dropdown-item" href="./hygiene.html"><p style="color:green;">Hygiene</p></a>
<a class="dropdown-item" href="./toys.html"><p style="color:green;">Toys</p></a>
</div>
</li>
<li class="nav-item dropdown">
<a class="nav-link" href="javscript:void(0)" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
<i class="material-icons">pets</i>
<span class="notification">Pet Adoption</span>
<p class="d-lg-none d-md-block">
Some Actions
</p>
</a>
<div class="dropdown-menu dropdown-menu-right" aria-labelledby="navbarDropdownMenuLink">
<a class="dropdown-item" href="./icons.html"><p style="color:green;">Dog</p></a>
<a class="dropdown-item" href="./cat.html"><p style="color:green;">Cat</p></a>
</div>
</li>
<li class="nav-item ">
<a class="nav-link" href="./login.html">
<i class="material-icons">logout</i>
<p>logout</p>
</a>
</li>
<!-- <li class="nav-item active-pro ">
<a class="nav-link" href="./upgrade.html">
<i class="material-icons">unarchive</i>
<p>Upgrade to PRO</p>
</a>
</li> -->
</ul>
</div>
</div>
<div class="main-panel">
<!-- Navbar -->
<nav class="navbar navbar-expand-lg navbar-transparent navbar-absolute fixed-top " id="navigation-example">
<div class="container-fluid">
<div class="navbar-wrapper">
<a class="navbar-brand" href="javascript:void(0)">Dashboard</a>
</div>
<button class="navbar-toggler" type="button" data-toggle="collapse" aria-controls="navigation-index" aria-expanded="false" aria-label="Toggle navigation" data-target="#navigation-example">
<span class="sr-only">Toggle navigation</span>
<span class="navbar-toggler-icon icon-bar"></span>
<span class="navbar-toggler-icon icon-bar"></span>
<span class="navbar-toggler-icon icon-bar"></span>
</button>
<div class="collapse navbar-collapse justify-content-end">
<form class="navbar-form">
<div class="input-group no-border">
<input type="text" id="Search1" value="" class="form-control" placeholder="Search...">
<button type="submit" id="Search2" class="btn btn-default btn-round btn-just-icon">
<i class="material-icons">search</i>
<div class="ripple-container"></div>
</button>
</div>
</form>
</div>
</nav>
<!-- End Navbar -->
<div class="content">
<div class="container-fluid">
<div class="row">
<div class="col-xl-3 col-lg-6 col-md-6 col-sm-6">
<a href="#">
<div class="card card-stats">
<div class="card-header card-header-warning card-header-icon">
<div class="card-icon">
<i class="material-icons">face</i>
</div>
<p class="card-category">New Users</p>
<h3 class="card-title">
<small></small>
</h3>
</div>
<div class="card-footer">
<div class="stats">
</div>
</div>
</div>
</div>
<div class="col-xl-3 col-lg-6 col-md-6 col-sm-6">
<a href="reports.html">
<div class="card card-stats">
<div class="card-header card-header-success card-header-icon">
<div class="card-icon">
<i class="material-icons">report_problem</i>
</div>
<p class="card-link" href="./dashboard.html">
<p class="card-category" >Reports</p>
<h3 class="card-title"></h3>
</div>
<div class="card-footer">
<div class="stats">
</div>
</div>
</div>
</div>
<div class="col-xl-3 col-lg-6 col-md-6 col-sm-6">
<a href=".">
<div class="card card-stats">
<div class="card-header card-header-danger card-header-icon">
<div class="card-icon">
<i class="material-icons">pets</i>
</div>
<p class="card-category">New Pet for Adoption</p>
<h3 class="card-title"></h3>
</div>
<div class="card-footer">
<div class="stats">
</div>
</div>
</div>
</div>
<div class="col-xl-3 col-lg-6 col-md-6 col-sm-6">
<a href="#">
<div class="card card-stats">
<div class="card-header card-header-info card-header-icon">
<div class="card-icon">
<i class="material-icons">add_shopping_cart</i>
</div>
<p class="card-category" href="./dashboard.html">New Product</p>
<h3 class="card-title"></h3>
</div>
<div class="card-footer">
<div class="stats">
</div>
</div>
</div>
</div>
</div>
<div class="row">
<div class="col-lg-12 col-md-12">
<a href="#">
<div class="card">
<div class="card-header card bg-success text-white">
<h4 class="card-title">Account List</h4>
</div>
<div class="card-body table-responsive">
<table class="table table-hover">
<thead class="text-warning">
<th>Name</th>
<th>Address</th>
<th>Contact</th>
<th>Delete</th>
</thead>
<tbody id="table_body">
</tbody>
</table>
</div>
</div>
</div>
</div>
</div>
<script src="https://www.gstatic.com/firebasejs/5.5.8/firebase.js"></script>
<script>
// Initialize Firebase
var config = {
apiKey: "AIzaSyBHzWLC1UCPrwI0lTsWdmTQWlles05unb0",
authDomain: "happy-paws-6f139.firebaseapp.com",
databaseURL: "https://happy-paws-6f139.firebaseio.com",
projectId: "happy-paws-6f139",
storageBucket: "happy-paws-6f139.appspot.com",
messagingSenderId: "53124089069"
};
firebase.initializeApp(config);
</script>
<script src="https://code.jquery.com/jquery-3.1.0.js"></script>
<script src="accountview.js"></script>
<script src="firebase.js"></script>
<script src="login.js"></script>
<div class="fixed-plugin">
<div class="dropdown show-dropdown">
<a href="#" data-toggle="dropdown">
<i class="fa fa-cog fa-2x"> </i>
</a>
<ul class="dropdown-menu">
<li class="header-title"> Sidebar Filters</li>
<li class="adjustments-line">
<a href="javascript:void(0)" class="switch-trigger active-color">
<div class="badge-colors ml-auto mr-auto">
<span class="badge filter badge-purple active" data-color="purple"></span>
<span class="badge filter badge-azure" data-color="azure"></span>
<span class="badge filter badge-green" data-color="green"></span>
<span class="badge filter badge-warning" data-color="orange"></span>
<span class="badge filter badge-danger" data-color="danger"></span>
</div>
<div class="clearfix"></div>
</a>
</li>
<li class="header-title">Images</li>
<li>
<a class="img-holder switch-trigger" href="javascript:void(0)">
<img src="../assets/img/sidebar-1.jpg" alt="">
</a>
</li>
<li class="active">
<a class="img-holder switch-trigger" href="javascript:void(0)">
<img src="../assets/img/sidebar-2.jpg" alt="">
</a>
</li>
<li>
<a class="img-holder switch-trigger" href="javascript:void(0)">
<img src="../assets/img/sidebar-3.jpg" alt="">
</a>
</li>
<li>
<a class="img-holder switch-trigger" href="javascript:void(0)">
<img src="../assets/img/sidebar-4.jpg" alt="">
</a>
</li>
<!-- Core JS Files -->
<script src="../assets/js/core/jquery.min.js"></script>
<script src="../assets/js/core/popper.min.js"></script>
<script src="../assets/js/core/bootstrap-material-design.min.js"></script>
<script src="https://unpkg.com/default-passive-events"></script>
<script src="../assets/js/plugins/perfect-scrollbar.jquery.min.js"></script>
<!-- Place this tag in your head or just before your close body tag. -->
<script async defer src="https://buttons.github.io/buttons.js"></script>
<!-- Google Maps Plugin -->
<script src="https://maps.googleapis.com/maps/api/js?key=YOUR_KEY_HERE"></script>
<!-- Chartist JS -->
<script src="../assets/js/plugins/chartist.min.js"></script>
<!-- Notifications Plugin -->
<script src="../assets/js/plugins/bootstrap-notify.js"></script>
<!-- Control Center for Material Dashboard: parallax effects, scripts for the example pages etc -->
<script src="../assets/js/material-dashboard.js?v=2.1.0"></script>
<!-- Material Dashboard DEMO methods, don't include it in your project! -->
<script src="../assets/demo/demo.js"></script>
<script>
$(document).ready(function() {
$().ready(function() {
$sidebar = $('.sidebar');
$sidebar_img_container = $sidebar.find('.sidebar-background');
$full_page = $('.full-page');
$sidebar_responsive = $('body > .navbar-collapse');
window_width = $(window).width();
$('.fixed-plugin a').click(function(event) {
// Alex if we click on switch, stop propagation of the event, so the dropdown will not be hide, otherwise we set the section active
if ($(this).hasClass('switch-trigger')) {
if (event.stopPropagation) {
event.stopPropagation();
} else if (window.event) {
window.event.cancelBubble = true;
}
}
});
$('.fixed-plugin .active-color span').click(function() {
$full_page_background = $('.full-page-background');
$(this).siblings().removeClass('active');
$(this).addClass('active');
var new_color = $(this).data('color');
if ($sidebar.length != 0) {
$sidebar.attr('data-color', new_color);
}
if ($full_page.length != 0) {
$full_page.attr('filter-color', new_color);
}
if ($sidebar_responsive.length != 0) {
$sidebar_responsive.attr('data-color', new_color);
}
});
$('.fixed-plugin .background-color .badge').click(function() {
$(this).siblings().removeClass('active');
$(this).addClass('active');
var new_color = $(this).data('background-color');
if ($sidebar.length != 0) {
$sidebar.attr('data-background-color', new_color);
}
});
$('.fixed-plugin .img-holder').click(function() {
$full_page_background = $('.full-page-background');
$(this).parent('li').siblings().removeClass('active');
$(this).parent('li').addClass('active');
var new_image = $(this).find("img").attr('src');
if ($sidebar_img_container.length != 0 amp;amp; $('.switch-sidebar-image input:checked').length != 0) {
$sidebar_img_container.fadeOut('fast', function() {
$sidebar_img_container.css('background-image', 'url("' new_image '")');
$sidebar_img_container.fadeIn('fast');
});
}
if ($full_page_background.length != 0 amp;amp; $('.switch-sidebar-image input:checked').length != 0) {
var new_image_full_page = $('.fixed-plugin li.active .img-holder').find('img').data('src');
$full_page_background.fadeOut('fast', function() {
$full_page_background.css('background-image', 'url("' new_image_full_page '")');
$full_page_background.fadeIn('fast');
});
}
if ($('.switch-sidebar-image input:checked').length == 0) {
var new_image = $('.fixed-plugin li.active .img-holder').find("img").attr('src');
var new_image_full_page = $('.fixed-plugin li.active .img-holder').find('img').data('src');
$sidebar_img_container.css('background-image', 'url("' new_image '")');
$full_page_background.css('background-image', 'url("' new_image_full_page '")');
}
if ($sidebar_responsive.length != 0) {
$sidebar_responsive.css('background-image', 'url("' new_image '")');
}
});
$('.switch-sidebar-image input').change(function() {
$full_page_background = $('.full-page-background');
$input = $(this);
if ($input.is(':checked')) {
if ($sidebar_img_container.length != 0) {
$sidebar_img_container.fadeIn('fast');
$sidebar.attr('data-image', '#');
}
if ($full_page_background.length != 0) {
$full_page_background.fadeIn('fast');
$full_page.attr('data-image', '#');
}
background_image = true;
} else {
if ($sidebar_img_container.length != 0) {
$sidebar.removeAttr('data-image');
$sidebar_img_container.fadeOut('fast');
}
if ($full_page_background.length != 0) {
$full_page.removeAttr('data-image', '#');
$full_page_background.fadeOut('fast');
}
background_image = false;
}
});
$('.switch-sidebar-mini input').change(function() {
$body = $('body');
$input = $(this);
if (md.misc.sidebar_mini_active == true) {
$('body').removeClass('sidebar-mini');
md.misc.sidebar_mini_active = false;
$('.sidebar .sidebar-wrapper, .main-panel').perfectScrollbar();
} else {
$('.sidebar .sidebar-wrapper, .main-panel').perfectScrollbar('destroy');
setTimeout(function() {
$('body').addClass('sidebar-mini');
md.misc.sidebar_mini_active = true;
}, 300);
}
// we simulate the window Resize so the charts will get updated in realtime.
var simulateWindowResize = setInterval(function() {
window.dispatchEvent(new Event('resize'));
}, 180);
// we stop the simulation of Window Resize after the animations are completed
setTimeout(function() {
clearInterval(simulateWindowResize);
}, 1000);
});
});
});
</script>
<script>
$(document).ready(function() {
// Javascript method's body can be found in assets/js/demos.js
md.initDashboardPageCharts();
});
</script>
</body>
</html> 
Ответ №1:
Чтобы получить key , вы можете сделать следующее:
rootRef.on("child_added", snap => {
var key = snap.key;
var name = snap.child("name").val();
var add = snap.child("address").val();
var contact = snap.child("contact").val();
$("#table_body").append("<tr><td>" name "</td><td>" add "</td><td>" contact "</td><td>");
$("#table_body").append('<button id="1" onClick="reply_click(' key ')">Delete</button></td></tr>');
});
function reply_click(clicked_id){
firebase.database().ref("User").child(clicked_id).remove();
}
snap.key Сможет получить уникальный идентификатор в базе данных.
Из документов:
Ключ (последняя часть пути) к местоположению этого снимка данных.
Комментарии:
1. это не работает, сэр. я также попытался заменить ‘<идентификатор кнопки=»1″ onClick =»reply_click (this.id )»> Удалить</button></td></tr>’ в ‘<button id=»1″ onClick =»reply_click (key)»> Удалить</button></td></tr>’ и это все еще не работает.
2. @LancerEX взгляните на обновление (с
onClick="reply_click(key)"-которым я добавил к ответу Питера), мы фактически передавали строковое значение «key» вreply_clickфункцию. Теперь сonClick="reply_click(' key ')"все должно быть в порядке.3. это все еще не работает. Я думаю, что проблема в моей «функции reply_click», но я не уверен.
4. Код вашей функции должен быть похож:
firebase.database().ref("User").child(clicked_id).remove();5. @RenaudTarnec все в порядке, не беспокойтесь!!