Develop Reference

How to get a selected value from HTML and handle it in js or php?

I have created an array of events and now I have a filter by location dropdown. How do I get the value selected in the dropdown and handle it in js or php? Which one would it be better so it shows events from that location and not all the events. I have have different files one for displaying the events (events.js and events.php) and the other files (filterevents.js and filter events.php) this is what I want to handle the filtering in.
HTML
<div class="events">
<form method="POST" id="eventForm">
Filter By Location<br/>
<select name="Locations">
<option value="Leeds">Leeds</option>
<option value="Newcastle">Newcastle</option>
<option value="London">London</option>
</select>
<input type="submit" name="submit" value="Search"/>
</form>
<div class="eventname"><!--obj.eventname--></div>
<div class="date"><!--obj.date--></div>
<div class="time"><!--obj.time--></div>
<div class="location"><!--obj.location--></div>
<p id="error" class="errormessage"></p>
<p id="allevents" class="postmessage"></p>
</div>
events.php
<?php
require_once('checklog.php');
require_once("db_connect.php");
require_once("functions.php");
session_start();
// Print out existing events
$query = "SELECT eventname, date, time, location FROM events ORDER BY eventname";
$result = mysqli_query($db_server, $query);
if (!$result)
die("Database access failed: " . mysqli_error($db_server));
while ($row = mysqli_fetch_array($result)) {
$events[] = $row;
}
mysqli_free_result($result);
require_once("db_close.php");
echo json_encode($events);
?>
events.js
$(document).ready(function() {
var events = document.getElementById("allevents").value;
// Call Ajax for existing comments
$.ajax({
type: 'GET',
url: 'events.php',
success: function(result) {
var arr = JSON.parse(result);
for(var i = 0; i < arr.length; i++) {
var obj = arr[i];
var output = document.getElementById("allevents");
output.innerHTML += '<div class="comment-container"><div class="eventname">'+obj.eventname+'</div><div class="date">'+obj.date+'</div><div class="time">'+obj.time+'</div><div class="location">'+obj.location+'</div></div>';
}
}
});
filterevents.php
<?php
require_once('checklog.php');
require_once("db_connect.php");
require_once("functions.php");
This is where I want to filter but not sure how to do it.
?>
filterevents.js
// When post button is clicked
$(document).ready(function() {
var forum = $("#eventForm");
$("#eventForm").on('submit', function(event) {
event.preventDefault();
var events = new FormData(this);
if (events) {
// Call Ajax for new comment
$.ajax({
type: 'POST',
url: 'filterevents.php',
data: events,
processData: false,
contentType: false,
success: function(response) {
if(response == "Success")
{
document.getElementById("comment").innerHTML = response;
} else {
document.getElementById("error").innerHTML = response;
}
}
});
} else {
document.getElementById("error").innerHTML = "Please Select A Location";
}
return false;
});
});

How can I add select2 dynamic select box inside a while loop?

I'm trying to put a Select2 box inside a while loop. But it only works the first select tag. Although loop works fine, the select tag is not working after the first 1. how can I fix this issue?
I also tried adding printing PHP unique id to fix it. but nothing happened.
<select type="text" name="city" id="city-<?php echo $id; ?>" class="form-control"></select>
This is the javascript part:
<script type="text/javascript">
$('#city-<?php echo $id; ?>').select2({
placeholder: 'Select city',
ajax: {
url: 'processes/cities.php',
dataType: 'json',
delay: 250,
processResults: function (data) {
return {
results: data
};
},
cache: true
}
});
</script>
I'm expecting all the select boxes to work fine. But actually, only first 1 works.

It would be helpful if you provided the loop in your code example.
The most likely problem is that your id's are not unique. If you have multiple tags with the same id then javascript will only recognize the first one.
Here's an example to demonstrate.
https://jsfiddle.net/n8vxjoc1/1/
<div id="city-1">Content</div>
<div id="city-1">Content</div>
<script>
jQuery( '#city-1' ).html( jQuery( '#city-1' ).length );
</script>
Only the 1st element will change and it will display the number 1.
From the W3C specs:
The id attribute specifies its element's unique identifier (ID).
https://www.w3.org/TR/2011/WD-html5-20110525/elements.html#the-id-attribute
You should give the select dropdowns a class and target that instead.
E.g.
https://jsfiddle.net/n8vxjoc1/1/
<select name="city" class="select2 form-control">…</select>
<select name="city" class="select2 form-control">…</select>
<script type="text/javascript">
$('select.select2').select2({});
</script>

You can take help from this link: Demo
<select class="select2_el" style='width: 200px;'>
<option value='0'>- Search user -</option>
</select>
<div id='elements'>
</div>
<input type="button" id="btn_add" value="Add">
PHP:
<?php
include 'config.php';// add your config details on that file
$request = 1;
if(isset($_POST['request'])){
$request = $_POST['request'];
}
// Select2 data
if($request == 1){
if(!isset($_POST['searchTerm'])){
$fetchData = mysqli_query($con,"select * from users order by name limit 5");
}else{
$search = $_POST['searchTerm'];
$fetchData = mysqli_query($con,"select * from users where name like '%".$search."%' limit 5");
}
$data = array();
while ($row = mysqli_fetch_array($fetchData)) {
$data[] = array("id"=>$row['id'], "text"=>$row['name']);
}
echo json_encode($data);
exit;
}
// Add element
if($request == 2){
$html = "<br><select class='select2_el' ><option value='0'>- Search user -</option></select><br>";
echo $html;
exit;
}
JS
$(document).ready(function(){
// Initialize select2
initailizeSelect2();
// Add <select > element
$('#btn_add').click(function(){
$.ajax({
url: 'ajaxfile.php',
type: 'post',
data: {request: 2},
success: function(response){
// Append element
$('#elements').append(response);
// Initialize select2
initailizeSelect2();
}
});
});
});
// Initialize select2
function initailizeSelect2(){
$(".select2_el").select2({
ajax: {
url: "ajaxfile.php",
type: "post",
dataType: 'json',
delay: 250,
data: function (params) {
return {
searchTerm: params.term // search term
};
},
processResults: function (response) {
return {
results: response
};
},
cache: true
}
});
}

change function ajax call from php file

The following code consists of drop-down "(id=name" which populates from "listplace.php" through ajax call which works correctly.
Now I am trying to make another ajax call using the change function. when I select the particular item already populated on dropdown box it has to pass the selected item name1 in 'where' query to dataprod.php and has to display the products by clearing the existing products list available.
I am doubtful over the $name1 response from dataprod.php. Please help!!
<script src="https://code.jquery.com/jquery-3.2.1.min.js"></script>
<script>
$.ajax({
type: "POST",
data: {place: '<?= $_GET['place'] ?>'},
url: 'listplace.php',
dataType: 'json',
success: function (json) {
if (json.option.length) {
var $el = $("#name");
$el.empty(); // remove old options
for (var i = 0; i < json.option.length; i++) {
$el.append($('<option>',
{
value: json.option[i],
text: json.option[i]
}));
}else {
alert('No data found!');
}
}
});
</script>
ajax 2
$(document).ready(function(){
$("#name").change(function(){
var name1 = this.value;
$.ajax ({
url: "dataprod.php",
data: {place: '<?= $_GET['name1'] ?>'},
success: function (response) {
$('.products-wrp').html('')
$('.products-wrp').html(response);
}
}else {
$('.products-wrp').html('');
}
}
dataprod.php
<?php
include("config.inc.php");
$name1 = $_POST['name1'];
$results = $mysqli_conn->query("SELECT product_name, product_desc, product_code,
product_image, product_price FROM products_list where product_name='$name1'");
$products_list = '<ul id ="products_list" class="products-wrp">';
while($row = $results->fetch_assoc()) {
$products_list .= <<<EOT
<li>
<form class="form-item">
<h4>{$row["product_name"]}</h4>
<div>
<img src="images/{$row["product_image"]}" height="62" width="62">
</div>
<div>Price : {$currency} {$row["product_price"]}<div>
</form>
</li>
EOT;
}
$products_list .= '</ul></div>';
echo $products_list;
?>

Since you are calling ajax event on element which is loaded via ajax action so the change event is not bind and nothing is happend.
For ajax 2 action use below code.
$(document.body).on('change',"#name",function (e) {
//doStuff
var name1 = this.value;
$.ajax ({
url: "dataprod.php",
data: {place: '<?= $_GET['name1'] ?>'},
success: function (response) {
$('.products-wrp').html('')
$('.products-wrp').html(response);
}
}else {
$('.products-wrp').html('');
}
}

Sent value and show output when select tag change

I new in term of using jQuery.
I practice using native php ajax, but for this time I need to learn jQuery for the current technology and demand.
I sent "types" value method POST to other page (ajaxInfo.php) when the tag change.
After the select tag change, it should show the result at <div id="showList"> that come from database (MySQL). But nothing happen.
Below are the source code.
Body
<select id="form-types" class="col-xs-10 col-sm-5" name="types">
<option value="">PLEASE CHOSE</option>
<option value="STATE">STATE</option>
<option value="FACULTY">FACULTY</option>
<option value="PROGRAME">PROGRAME</option>
</select>
<div id="showList"></div>
jQuery AJAX
<script type = "text/javascript" >
$(document).ready(function () {
$("select#form-types").change(function () {
var types = $("select#form-types").val();
if (types != null) {
$.ajax({
type: 'post',
url: 'ajaxInfo.php',
data: "types=" + types,
dataType: 'html',
success: function (response) {
$("#showList").html(response);
}
}
});
});
});
</script>
Post Page (ajaxInfo.php)
<?php
if (isset($_POST["types"]) === TRUE){
$types = $_POST["types"];
}
else{
$types = null;
}
include '../dbco.php';
$query = $dbc -> query ("SELECT child FROM infobase WHERE parent='$types'");
if ($query -> num_rows > 0){
echo "LIST OF : " . $types . "REGISTERED<br />";
$count = 1;
while ($result = $query -> fetch_assoc()){
echo "$count" . $result['child'] . "<br />";
count++;
}
}else{
echo "NO " . $types . " REGISTERED";
}
?>
Thank You.

You are using id (form-types) for your select input field. but your are tying to targeting another id (form-jenis).
use same named id for select input field and in your jquery selector.
<script type="text/javascript">
$(document).ready(function(){
$("select#form-types").change(function(e){
e.preventDefault();
var types= $("select#form-types").val();
if (types!= null)
{
$.ajax({
type: 'post',
url: 'show.php',
data: "types=" + types,
dataType: 'html',
success: function(response)
{
$("#showList").html(response);
}
}
});
});

You have a missing bracket
<script type="text/javascript">
$(document).ready(function(){
$("select#form-types").change(function(){
var types= $("select#form-types").val();
if (types!= null)
{
$.ajax({
type: 'post',
url: 'ajaxInfo.php',
data: "types=" + types,
dataType: 'html',
success: function(response)
{
$("#showList").html(response);
}
}
});
});
}); // add this
</script>

I found out that my ajax jQuery function do not have close pair, so i decide to add it and it work.
<script type="text/javascript">
$(document).ready(function(){
$("select#form-types").change(function(){
var types= $("select#form-types").val();
if (types!= null)
{
$.ajax({
type: 'post',
url: 'ajaxInfo.php',
data: "types=" + types,
dataType: 'html',
success: function(response)
{
$("#showList").html(response);
}
}); // Add This
}
});
});
</script>
After the code running good, i also found out the error at ajaxInfo.php, the count inside the loop missing $ symbol
if ($query -> num_rows > 0)
{
echo "LIST OF : " . $types . "REGISTERED<br />";
$count = 1;
while ($result = $query -> fetch_assoc())
{
echo "$count" . $result['child'] . "<br />";
$count++; //HERE
}
}
Thanks for the people that help.

Dynamically created select list makes mutilple calls to javascript function

I have created dynamically multiple select list. On click of channel name it should get its type. The problem is once click on select list its repetitively calls java script function causing ajax to load multiple times.
HTML CODE:
<td>
<SELECT name="channel_name[]" onclick ="get_type(this)"; required class='channelname'>
<option value="">Select...</option>
<?php foreach($channel_list as $row) {
$channelid = $row['channelid'];
$channelname = $row['channelname'];
if($U_channelid==$channelid)
{
$s = "selected = selected";
}
else
{
$s = "";
}
echo "<option value='$channelid' $s>".$channelname."</option>";
?>
<!-- <OPTION value='<?php echo $channelid ?>' $s ><?php echo $channelname?></OPTION> -->
<?php } ?>
</SELECT>
</td>
Javascipt code:
function get_type()
{
$(".channelname").live("change", function() {
var channel_id = $(this).find("option:selected").attr("value");
var _this = $(this); //Save current object
alert(channel_id);
$.ajax({
type: "POST",
url: '<?php echo base_url(); ?>index.php/partner/get_channel_type',
data: 'channelid='+channel_id,
async: false
}).done(function( data1 ) {
if(data1){
_this.closest("tr").find('input[name="type[]"]').val(data1);
}else{
alert("Channel type is not defined");
_this.closest("tr").find('input[name="type[]"]').val("");
}
});
});
}

remove onclick ="get_type(this)" from select tag // because you already using $(".channelname").live("change", function() { in javascript
put this
<SELECT name="channel_name[]" required class='channelname'>
and javascript
$(".channelname").change(function() {
var channel_id = $('.channelname').find("option:selected").attr("value");
alert(channel_id);
$.ajax({
type: "POST",
url: '<?php echo base_url(); ?>index.php/partner/get_channel_type',
data: 'channelid='+channel_id,
async: false
}).done(function( data1 ) {
if(data1){
_this.closest("tr").find('input[name="type[]"]').val(data1);
}else{
alert("Channel type is not defined");
_this.closest("tr").find('input[name="type[]"]').val("");
}
});
});