Passing values from JS to PHP and Echo back HTML - javascript

I am studying a code and need help to learn further.
The JS code below is from a Q/A html form that sends data to server.
It crosschecks answer and on server and scores the user.
I need help writing a PHP code that receives the inputs using GET method and echo "ok" back to the html.
JS:
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if(this.readyState == 4 && this.status == 200) {
if(this.responseText == "ok") {
document.getElementById("messagefont").innerHTML = checkans;
document.getElementById("answer").value = "";
document.getElementById('submit-btn').value = continuebutton;
checkans.focus();
PHP:
<?php
header('Content-Type: application/json');
$errors = array ();
if (!empty($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest' );
if (isset ($_GET['answer'])) {
$answer = $_GET["answer"];
}
else {
array_push ($errors, no);
}
$response = "";
if (sizeof ($errors) > 0) {
$response = implode (",", $errors);
}
else {
$response = ok;
}
echo json_encode($response);
?>
I seem not to be getting something right with the PHP, please i need assistance/guide to fix the PHP code rightly.

Related

POST data in JavaScript is not being sent

Here's my JavaScript code to post to my API:
var pageRequest = new XMLHttpRequest();
pageRequest.open("POST", "/api.php", true);
pageRequest.onreadystatechange = function() {
if (pageRequest.readyState === 4 && pageRequest.status === 200) {
console.log(pageRequest.responseText);
}
}
pageRequest.send("firstname=John&lastname=Doe");
And here is my PHP backend code:
<?php
if (isset($_POST["firstname"]) && isset($_POST["lastname"])) {
$first_name = $_POST["firstname"];
$last_name = $_POST["lastname"];
echo "Hello, " . htmlspecialchars($first_name) . " " . htmlspecialchars($last_name);
} else {
echo "Please include all fields.";
}
?>
However, my PHP code just echos "Please include all fields.", and when I try doing
var_dump($_POST);
It returns an empty array. Am I doing something wrong here?
Thanks.
You are likely missing setup of request header:
var pageRequest = new XMLHttpRequest();
pageRequest.open("POST", "/api.php", true);
pageRequest.onreadystatechange = function() {
if (pageRequest.readyState === 4 && pageRequest.status === 200) {
console.log(pageRequest.responseText);
}
}
*** pageRequest.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8");
pageRequest.send("firstname=John&lastname=Doe");

echo is adding a new line to what i output in PHP

I am sending echoing some data to be received in Javascript however when i debug it, it seems that a new line has been added.
PHP
<?php
header("Content-Type: application/json; charset=UTF-8");
require './connection.php';
$obj = json_decode($_POST["x"], false);
$usernamequery = "SELECT * FROM User WHERE username='$obj->newUser'";
$result = mysqli_query($db, $usernamequery);
$row = mysqli_fetch_assoc($result);
if($row["Username"] == null){
$updatequery = "UPDATE User SET User='$obj->newUser' WHERE username ='$obj->username'";
$result = mysqli_query($db, $updatequery);
echo "valid";
} else{
echo "invalid";
}
?>
JS
///// USERNAME
$(document).ready(function () {
$("#userSubmitForm").on("click", function(e) {
$username = document.getElementById("user").value;
$newUser = document.getElementById("newUser").value;
user = $newUser;
obj = { "username":$username, "newUser":$newUser};
dbParam = JSON.stringify(obj);
xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState === 4 && this.status === 200) {
validity = this.responseText;
if (validity === "valid"){
$('#usernameModal .modal-header .modal-title').html("Result");
$('#usernameModal .modal-body').html("Your Username Has Been Changed to '$newUser'");
$("#passSubmitForm").remove();
$("#userCloseForm").remove();
window.setTimeout(redirect,3000);
} else{
$('#error').html("This Username Already Exists"); ;
}
}
};
What is happening is responseText will be receive "valid"/"Invalid" as "valid[newline]"/"invalid[newline]"
As stated at http://php.net/manual/en/function.echo.php that can't be a "problem" of the echo. There must be some newline-character after your -tags
A simple solution would be to just trim your response text like this: var validity = this.responseText.trim(); in order to strip it from unwanted space/tab/newline characters.

Javascript AJAX PHP if statement not working

I've been struggling with this problem for over two hours now and can find any reasonable solution. If i will get rid of if statement marked by ---> this arrow. alert() on its on will work. It will will be triggered when i just put if(true) but it don't work with following condition. I'm not really good with this languages. Just have to finish that for school project. I'm sure it is something small but cat figure it out on my own.
Java Script Function
function checkLogin(str) {
if (str.length == 0) {
return;
} else {
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == 4 && xmlhttp.status == 200) {
var ret = xmlhttp.responseText;
----> if (ret == "match"){
alert("Login name already exists !");
}
}
}
xmlhttp.open("GET", "loginCheck.php?q=" + str, true);
xmlhttp.send();
}
}
PHP Code
/*
<?php
include 'db.inc.php';
date_default_timezone_set("UTC");
$login = $_REQUEST["q"];
$sql = "SELECT * FROM staffMembers";
if (!($result = mysqli_query($con,$sql))){
die ('An Error ->' . mysqli_error() );
}
while ($row = mysqli_fetch_array($result)){
$firstName = $row['nameLogin'];
$ret="true";
if($firstName == $login){
$ret = "match";
break;
}
}
mysqli_close($con);
echo $ret;
?>
*/
Your PHP code has possibly output whitespace around match. Try this
if (ret.trim() == "match"){

Can't Pass Data From PHP to AJAX

I have an input box in html. The input searches an database through ajax and return the results in front-end. The problem is that I don't get the result from PHP. I don't know what I did wrong, so I hope you guys have a better understanding from me.
HTML
<body onload="AjaxFindPerson()">
.....
</body>
JS
var xmlHttp = createXmlHttpRequestObject();
function AjaxFindPerson() {
if ((xmlHttp.readyState == 0 || xmlHttp.readyState == 4) && document.getElementById("PersonSearchInput").value != "") {
person = encodeURIComponent(document.getElementById("PersonSearchInput").value);
xmlHttp.open("GET", "../lib/search.php?email=" + person, true);
xmlHttp.onreadystatechange = handleServerResponse;
xmlHttp.send(null);
}
else {
document.getElementById('Label-Result').innerHTML = "";
document.getElementById('UserNameSearchResult').innerHTML = "";
$('#add-person-btn').attr("disabled", "disabled");
setTimeout('AjaxFindPerson()', 1000);
}
}
function handleServerResponse() {
if (xmlHttp.readyState == 4 ) {
if (xmlHttp.status == 200) {
xmlResponse = xmlHttp.responseXML;
xmlDocumentElement = xmlResponse.documentElement;
result = xmlDocumentElement.firstChild.data;
if (result[0] != false) {
document.getElementById('Label-Result').innerHTML = result[1];
document.getElementById('UserNameSearchResult').innerHTML = result[0];
$('#add-person-btn').removeAttr("disabled", "disabled");
}
else {
document.getElementById('Label-Result').innerHTML = result[1];
}
setTimeout('AjaxFindPerson()', 1000);
}
else {
alert('Somenthing went wrong when tried to get data from server'+ xmlHttp.readyState);
}
}
}
PHP
<?php
header('Content-Type: text/xml');
echo '<?xml version="1.0" encoding="UTF-8" standalone="yes" ?>';
session_start();
define("DB_HOST", 'mysql6.000webhost.com');
define("DB_USER", '');
define("DB_PASSWORD", '');
define("DB_DATABSE", '');
echo '<response>';
$email = $_GET['email'];
$conn = mysql_connect(DB_HOST, DB_USER, DB_PASSWORD);
mysql_select_db(DB_DATABSE, $conn);
$sq = mysql_query("SELECT UserEmail FROM Users");
$UserInfo = array();
while ($row = mysql_fetch_array($sq, MYSQL_ASSOC)) {
$UserInfo[] = $row['UserEmail'];
}
if (in_array($email, $UserInfo)) {
$result = mysql_query("SELECT UserName FROM Users WHERE UserEmail = '".$email."'");
$row = mysql_fetch_row($result);
$returnRes = array($row[0], "We found results"); //row[0] holds the UserN
echo $returnRes;
}
else {
$returnRes = array(false, "We couldn't find results");
echo $returnRes;
}
echo '</response>';
?>
If we check the php-xml file alone will see the image bellow :
Do I need to pass the values to xml-php with another way?
UPDATE 1 in PHP
I manage to found a way to return the data correctly. Here are the update 'touch'
header('Content-Type: application/json');
and
if (in_array($email, $UserInfo)) {
$result = mysql_query("SELECT UserName FROM Users WHERE UserEmail = '".$email."'");
$row = mysql_fetch_row($result);
echo json_encode(array( 'found' => $row[0], 'msg' => "We found results"));
}
else {
echo json_encode(array( 'found' => null, 'msg' => "We couldn't find results"));
}
The problem now is how to manipulate the js file to handle the return array. I made a try but it didn't worked:
result = xmlDocumentElement.firstChild.data;
if (result['found'] != null) {
document.getElementById('Label-Result').innerHTML = result['msg'];
document.getElementById('UserNameSearchResult').innerHTML = result['found'];
$('#add-person-btn').removeAttr("disabled");
}
else {
document.getElementById('Label-Result').innerHTML = result['msg'];
}
**UPDATE 2 WORKING JS **
I figure out how to retrieve the data from PHP.
xmlResponse = xmlHttp.responseXML;
xmlDocumentElement = xmlResponse.documentElement;
var result = JSON.parse(xmlDocumentElement.firstChild.data);
if (result['found'] != null) {
document.getElementById('Label-Result').innerHTML = result['msg'];
document.getElementById('UserNameSearchResult').innerHTML = result['found'];
$('#add-person-btn').removeAttr("disabled");
}
else {
document.getElementById('Label-Result').innerHTML = result['msg'];
}
NOW ALL THE CODE IS WORKING! THANK YOU VERY MUCH GUYS!
+1 to all of you!
Four things :
Usage of send(null) doesn't seems to be right, just don't pass null in it.
Second one is timeout method. Instead the way you are using it, you can call it in the callback function or instead of string use the name at the function call.
The usage to remove the attribute is also wrong. It is currently using a set method as you have supplied a second argument. The remove attribute method only takes a attribute name.
I would rather suggest you to set a header for the application/json and use json_encode() method to return data.
For printing an array, you can either use json_encode(), or do somehow else transform your array into a string.
If we were to ignore the white elephant in the room and gloss over the use of mysql_* functions then a slightly different approach
<?php
session_start();
define('DB_HOST', 'mysql6.000webhost.com');
define('DB_USER', '');
define('DB_PASSWORD', '');
define('DB_DATABASE', '');
$dom=new DOMDocument('1.0','utf-8');
$root=$dom->createElement('response');
$dom->appendChild( $root );
if( $_SERVER['REQUEST_METHOD']=='GET' && isset( $_GET['email'] ) ){
/* Basic filtering IF mysql_* functions are used! */
$email = trim( strip_tags( filter_input( INPUT_GET, 'email', FILTER_SANITIZE_EMAIL ) ) );
$conn = mysql_connect( DB_HOST, DB_USER, DB_PASSWORD );
mysql_select_db( DB_DATABASE, $conn ) or die('error: database connection failed');
/* By the looks of the original there should be no need for two queries and then an array lookup */
$result = mysql_query("SELECT `UserName` FROM `Users` WHERE `UserEmail` = '".$email."';");
/* If there are results, add nodes to the dom object */
if( mysql_num_rows( $result ) > 0 ){
while( $rs=mysql_fetch_object( $result ) ){
$root->appendChild( $dom->createElement( 'user', $rs->UserName ) );
}
} else {
/* Otherwise add error message */
$root->appendChild( $dom->createElement( 'error', 'We couldn\'t find any results!' ) );
}
}
/* Send the xml back to the js client */
header('Content-Type: text/xml');
$xml=$dom->saveXML();
$dom=null;
exit( $xml );
?>

I can't retrieve JSON data array from php page to another

<?php
require_once './db_connect.php';
$db = new DB_Connect();
$db->connect();
$data = json_decode($_POST['myData']);
$array=json_decode($_REQUEST['question']);
if(isset($_POST['myData'])){
$obj = json_decode($_POST['myData']);
//some php operation
$q = "insert into questions(question)
values ('". $obj."')";
$result = mysql_query($q) or die(mysql_error());
}
?>
I want to retrieve the JSON data that is being sent from another php page to this page , but I just can't ,,why is that ?
here's the other page
function validateForm()
{
var q = document.forms["form1"]["question"].value;
var T = document.forms["form1"]["title"].value;
if (T == null || T == "")
{
alert("please type you form title first");
return false;
}
if (q == null || q == "")
{
document.getElementById("question").style.color="black";
alert("please enter your question");
return false;
}
question.push(q);
//alert(JSON.stringify(question));
var xhr = new XMLHttpRequest();
xhr.open('post', 'create_form.php',true);
// Track the state changes of the request
xhr.onreadystatechange = function(){
// Ready state 4 means the request is done
if(xhr.readyState === 4){
// 200 is a successful return
if(xhr.status === 200){
alert(xhr.responseText); // 'This is the returned text.'
}else{
alert('Error: '+xhr.status); // An error occurred during the request
}
}
}
// Send the request to send-ajax-data.php
xhr.send({myData:JSON.stringify(question)}); //+encodeURI(JSON.stringify(question))
// addField();
return true;
}
can someone please help me ??
I'm tried to solve this using jquery ajax , it's just the same ,, that's why i tried to use only javascript to solve this
try this
$json = file_get_contents('php://input');
$obj = json_decode($json, TRUE);
instead of this
$data = json_decode($_POST['myData']);
$array=json_decode($_REQUEST['question']);
if(isset($_POST['myData'])){
$obj = json_decode($_POST['myData']);

Categories

Resources