I want to send an Ajax request when clicking a button but it seems my request is never executed. Here is my HTML code :
<!DOCTYPE html>
<html lang="en">
<head>
<title>User Form</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.5.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.16.0/umd/popper.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js"></script>
<script src = "./actions.js"></script>
</head>
<body>
<div id="badFrm" class="container">
<h2><br>User Registration</h2>
<form id="Form" method="post">
<div class="form-group">
<label for="name">Name:</label>
<input type="name" class="form-control" id="name" placeholder="Enter Name" name="name">
</div>
<div class="form-group">
<label for="email">Email:</label>
<input type="email" class="form-control" id="email" placeholder="Enter Email" name="email">
</div>
<button id="submitBtn" class="btn btn-primary">Submit</button>
</form>
</div>
</body>
</html>
i feel there is something wrong with my javascript code but i cant figure whats wrong ! i changed a lot of it based on the comments i got earlier . what i want is when i click on the update button it changes to ” submit again “ and i want to replace “list items” ( name and email ) with input fields and put whatever written in them to be saved in the database instead . and eventually return to the first page which is the register form. i need help in this part !! i know this part is buggy . i need to know how to reach each list item individually ( what attribute should i add/use ) and here is my javascript code :
$(document).ready(function() {
var i ;
$("#submitBtn").click(function (e) {
e.preventDefault();
var name = $("#name").val();
var email = $("#email").val();
$.post("http://localhost/MiniProject/connect.php",
{
name: name,
email: email
}, function () {
var element = document.getElementById("badFrm");
element.remove();
showTbl();
});
function showTbl() {
$.post("http://localhost/MiniProject/Select.php",
{
name: name,
email: email
}, function (res) {
// console.log(res);
res = JSON.parse(res);
var html = '<ul id="List">';
for (i = 0; i < res.length; i++) {
var j = i +1 ;
html += '<li class = "name" >' + res[i].name + '</li><li class = "email">' + res[i].email + '</li>'+ '<div>' + '<button onclick="removeUser(this)" class="btn btn-primary">Remove</button>' + '<button onclick="updateUser(this)" class="btn btn-primary">Update</button>' + '</div>';
}
html += '</ul>';
document.body.innerHTML = html;
});
}
});
});
function removeUser(element){
var ID = element.id;
var element2 = document.getElementById("List");
element2.remove();
$.post("http://localhost/MiniProject/Remove.php",{
id : ID
}, function (res) {
console.log(res);
document.write(res);
});
//alert(element.id);
}
function updateUser(element){
// code ...
$.post("http://localhost/MiniProject/Update.php",{
id : ID2,
}, function (res) {
console.log(res);
// document.write(res);
});
}
here is connect.php :
<?php
require 'Users.php';
$name = $_POST['name'];
$email = $_POST['email'];
$conn = new mysqli('localhost','root','','mydatabasename');
if($conn->connect_error){
die('Connection Failed : '.$conn->connect_error);
}else {
$user = new Users();
$user->Insert(['name' => $name, 'email' => $email]);
echo "name is : ".$name." and email is : ".$email;
}
this is Users.php :
<?php
require 'newDB.php';
class Users extends DatabaseClass{
public $table = 'Users';
}
and this is where i handle the database commands :
<?php
class DatabaseClass{
public $connection = null;
public $table = null;
// this function is called everytime this class is instantiated
public function __construct( $dbhost = "localhost", $dbname = "myDatabaseName", $username = "root", $password = ""){
try{
// $conn = new PDO("mysql:host=$servername;dbname=$dbname", $username, $password);
$this->connection = new PDO("mysql:host=$dbhost;dbname=$dbname", $username, $password);
$this->connection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
$this->connection->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
$sql = "CREATE TABLE MyGuests (
id INT(6) UNSIGNED AUTO_INCREMENT PRIMARY KEY,
firstname VARCHAR(30) NOT NULL,
lastname VARCHAR(30) NOT NULL,
email VARCHAR(50),
reg_date TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP
)";
}catch(Exception $e){
throw new Exception($e->getMessage());
}
}
// Insert a row/s in a Database Table
public function Insert($parameters = [] ){
try{
$fields = array_keys($parameters);
$fields_string = '`' . implode('`,`', $fields) . '`';
$values_string = ':' . implode(',:', $fields);
$sql = "INSERT INTO `{$this->table}`({$fields_string}) VALUES ( {$values_string} )";
$this->executeStatement( $sql , $parameters );
return $this->connection->lastInsertId();
}catch(Exception $e){
throw new Exception($e->getMessage());
}
}
// Select a row/s in a Database Table
public function Select( $parameters = [] ){
try{
$fields = array_values($parameters);
$fields_string=implode(' , ',$fields);
$sql = "SELECT {$fields_string} FROM {$this->table}";
$stmt = $this->executeStatement( $sql , $parameters );
return $stmt->fetchAll();
}catch(Exception $e){
throw new Exception($e->getMessage());
}
}
// Update a row/s in a Database Table
public function Update( $parameters = [] ){
try{
$fields = array_keys($parameters);
$fields_string = 'id = '.implode($fields);
$sql = "UPDATE {$this->table} SET {$fields_string} WHERE {$fields_string} ";
echo $sql; exit ;
$this->executeStatement( $sql , $parameters );
}catch(Exception $e){
throw new Exception($e->getMessage());
}
}
// Remove a row/s in a Database Table
public function Remove( $parameters ){
try{
$fields_string = 'id = '.implode($parameters);
$sql = "DELETE FROM {$this->table} WHERE {$fields_string}";
$this->executeStatement( $sql , $parameters );
}catch(Exception $e){
throw new Exception($e->getMessage());
}
}
// execute statement
public function executeStatement( $statement = "" , $parameters = [] ){
try{
$stmt = $this->connection->prepare($statement);
$stmt->execute($parameters);
return $stmt;
}catch(Exception $e){
throw new Exception($e->getMessage());
}
}
}
and this is Update.php :
<?php
require 'Users.php';
$id = $_POST['id'];
$conn = new mysqli('localhost','root','','mydatabasename');
if($conn->connect_error){
die('Connection Failed : '.$conn->connect_error);
}else {
$user = new Users();
$result = $user->Update(['id'=>$id]);
// echo json_encode($result);
}
?>
i dont want the question to have a lot of code so hope this makes it better to understand.
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Answer
I mentioned posting something without jQuery – here is a demo which does what I understand your requirement to be. There are comments below to explain what is going on.
<?php
error_reporting( E_ALL );
if( $_SERVER['REQUEST_METHOD']=='POST' && isset( $_POST['action'] ) ){
ob_clean();
/*
This emulates ALL of the PHP endpoints used in the original code
-this is for demo purposes ONLY. The data returned is DEMO data
and should be ignored. All AJAX functions should be pointed at
their original endpoints... unless you adopt a similar approach
in which case include your various PHP classes here.
The ficticious sql in the below is for example only!
Obviously you would use `prepared statements`...
*/
switch( $_POST['action'] ){
case 'insert':
// do stuff...
// send response...
$data=sprintf('name is: %s and email is: %s',$_POST['name'],$_POST['email']);
break;
case 'remove':
header('Content-Type: application/json');
$data=json_encode(array(
'action' => $_POST['action'],
'name' => $_POST['name'],
'email' => $_POST['email'],
'sql' => sprintf('delete from `TABLE` where `email`="%s"', $_POST['email'] )
));
break;
case 'update':
header('Content-Type: application/json');
$data=json_encode(array(
'action' => $_POST['action'],
'name' => $_POST['name'],
'email' => $_POST['email'],
'sql' => sprintf('update `TABLE` set `col`=? where `email`="%s"', $_POST['email'] )
));
break;
}
exit( $data );
}
?>
<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='utf-8' />
<title></title>
<style>
.hidden{display:none}
</style>
<script>
document.addEventListener('DOMContentLoaded',()=>{
/*
I can see no benefit to having multiple endpoints to process
the different AJAX requests. You can structure a single script
to process each request rather like the above PHP code but
that is just an opinion. The following points ALL requests to
the same page for this demo.
The user's `email` address should be unique(?) so could be used
as the key in whatever sql query???
*/
const endpoints={
'insert':location.href, // 'MiniProject/connect.php'
'select':location.href, // 'MiniProject/Select.php'
'remove':location.href, // 'MiniProject/Remove.php'
'update':location.href // 'MiniProject/Update.php'
};
// Elements in the initial page/form
let cont=document.querySelector('div.container');
let form=document.forms.register;
let bttn=form.querySelector('button');
// the main callback - for the `Submit` button
const bttnclickhandler=function(e){
e.preventDefault();
let valid=true;
// check the form fields are not empty before continuing
let col=form.elements;
Array.from( col ).some( n => {
if( n.tagName=='INPUT' && n.value=='' ){
alert( '"' + n.name + '" cannot be empty' );
valid=false;
return true;
}
})
if( !valid )return false;
// Prepare the Payload to be sent, via AJAX POST, to the backend script/endpoint.
let fd=new FormData( form );
fd.append('action',this.dataset.action);
// Send the AJAX request
fetch( endpoints.insert, { method:'post', body:fd } )
.then( r=>r.text() )
.then( text=>{
// Hide the original form - do not remove it though... you want to reinstate this later
form.classList.add('hidden');
/*
create a clone of the template and then find the elements within
assign new values and bind event listeners.
*/
let oTmpl=document.querySelector('template#list-item').content.firstElementChild.cloneNode( true );
oTmpl.querySelector('[data-id="name"]').textContent=fd.get('name');
oTmpl.querySelector('[data-id="email"]').textContent=fd.get('email');
oTmpl.querySelectorAll('button[data-action]').forEach( n=>{
n.addEventListener('click',function(e){
let action=this.dataset.action;
let url=endpoints[ action ];
let fd=new FormData();
fd.append('action',action);
fd.append('name',e.target.parentNode.parentNode.querySelector('span[data-id="name"]').textContent);
fd.append('email',e.target.parentNode.parentNode.querySelector('span[data-id="email"]').textContent);
// send a new AJAX request
fetch( url, { method:'post', body:fd })
.then( r=>r.json() )
.then( json=>{
// the response...
console.log( json );
// show the original form and remove the clone
form.classList.remove('hidden');
cont.querySelector('ul#list').removeChild( oTmpl );
})
});
});
// Add the cloned template to the container
cont.querySelector('ul#list').appendChild( oTmpl )
})
};
// bind the event handler to the button.
bttn.addEventListener( 'click', bttnclickhandler );
});
</script>
</head>
<body>
<!--
All buttons below have dataset attributes
data-action='value' - this is used to decide
which piece of PHP code to process.
-->
<div class='container'>
<h2>User Registration</h2>
<form name='register' method='post'>
<div class='form-group'>
<label>
Name:
<input type='text' name='name' class='form-control' placeholder='Enter Name' />
</label>
</div>
<div class='form-group'>
<label>
Email:
<input type='email' name='email' class='form-control' placeholder='Enter Email' />
</label>
</div>
<button data-action='insert' class='btn btn-primary'>Submit</button>
</form>
<ul id='list'></ul>
</div>
<!--
The template will be called and populated
by ajax callback when the above `Submit`
button is clicked.
This will NOT appear in the DOM until
requested with Javascript.
The inner contents of this template
are cloned and inserted into the DOM.
-->
<template id='list-item'>
<li>
<span data-id='name'></span>
<span data-id='email'></span>
<div>
<button data-action='remove' class="btn btn-primary">Remove</button>
<button data-action='update' class="btn btn-primary">Update</button>
</div>
</li>
</template>
</body>
</html>