Can we send ajax from a javascript file? - javascript

since I wrote this code and it turned out that it is not entering the if statement ,My target was to bring the array from php(db) and put it in array in js,what to do?Here is the code ,is the problem that it is located in an extension js file ?Moreover php file getusercatpref.php is returning ["violen","ios","programming","nodjs"].
var arr = new Array();
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
var myArr = JSON.parse(this.responseText);
arr = myArr;
}
};
xmlhttp.open("GET", "getusercatpref.php", true);
xmlhttp.send();
PHP Code
<?php
$name="root";
$pas="";
$dbname="jobpursuit";
$con=mysqli_connect("localhost", $name, $pas,$dbname);
$arrayCategories = array();
$sql="Select * FROM preferences where username='12' ";
$result=mysqli_query($con,$sql);
$index=0;
while($row = mysqli_fetch_assoc($result)){
$arrayCategories[$index] = $row['categoryname'];
$index=$index+1;
}
echo json_encode($arrayCategories);
?>

Related

PHP fopen() inside javascript logic bug

I want to create a text file stole to localhost directory.
below is my code.
below app.php
document.getElementById("save_button").addEventListener("click", function() {
var content = document.getElementById("final_span").value();
var file_name =document.getElementById("filename").value();
<?php
$fn = strstr($file_name,'.', true);
$dir = "../project/Record";
$file = fopen($dir."/".$fn.".txt","w+");
fwrite($file, $content);
fclose($file);
?>
});
</script>```
Your js will execute in browser and php is server side language. You can't control php within js as you've done. You can do it by ajax call from you js to php file and create a file.
<script> document.getElementById("save_button").addEventListener("click", function() {
var content = document.getElementById("final_span").value;
var file_name =document.getElementById("filename").value;
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById("txtHint").innerHTML = this.responseText;
}
};
xmlhttp.open("GET", "app.php?file_name=" + file_name, true);
xmlhttp.send();
</script>
app.php
<?php $file_name= $_GET['file_name'];
$fn = strstr($file_name,'.', true);
$dir = "../project/Record";
$file = fopen($dir."/".$fn.".txt","w+");
fwrite($file, $content);
fclose($file);
?>

Return multiple data/responsetext from an XMLHttpRequest

I have a js function that calls in an xml request to fetch data from a separate php file. I can get a returned data through echoing it from the separate php file.
Here's my current code:
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function()
{
if(this.readyState == 4 && this.status == 200)
{
//On Data Receive
countryHeader.innerHTML = this.responseText;
}
};
xhttp.open("GET", "country.php?c=" + countryName, true);
xhttp.send();
And on my php:
include("conn.php");
$c = htmlentities($_GET["c"]);
$sec_country = mysqli_real_escape_string($con, $c);
//Searches the db
$sql = "SELECT * FROM countries WHERE country_code = '$sec_country' LIMIT 1";
$result = mysqli_query($con, $sql);
$count = mysqli_num_rows($result);
if($count == 1)
{
//Get Data
$row = mysqli_fetch_assoc($result);
$countryName = $row['country_name'];
$countryPrice = $row['country_price'];
echo $countryName." is worth $".$countryPrice;
}
else
{
//Invalid Code/No Data
echo "No Country Found";
}
If I send in a country code for example like rus, it would return Russia is worth $1B mainly from the echo $countryName." is worth $".$countryPrice;
But what if I want to separately send $countryName and $countryPrice?
For example responseText.a and responseText.b
You can send JSON response from PHP. Here is a reference -> https://www.w3schools.com/js/js_json_php.asp

Repeat PHP function every 2 seconds

So I have a code, where a number is retrieved from a text file and is displayed through HTML.
The thing is that it only retrieves the number when I refresh the page. If I change the number on other page, it doesn't change on the other page.
I've seen similar questions before, most of them said to use AJAX, but I don't understand much about AJAX and I only need it for this bit of code, it's not like I'm going to constantly use it. I would like to know if there is any other besides AJAX and if there is only AJAX, please present examples of code.
PHP code:
<?php
$file = "num.txt"; //Path to your *.txt file
$contents = file($file);
$num = implode($contents);
?>
JavaScript code. Basically it gets the PHP value and outputs to the html.
document.getElementById("num").innerHTML = '<?php echo $num; ?>';
Keep in mind, I don't want to refresh the page. Just the variable.
EDIT: PHP code - Getting an error - Notice: Undefined index: keynum in C:\xampp\htdocs\num.php on line 3
Here is the code of the PHP
<?php
$keynum = $_POST['keynum'];
$post = "INSERT INTO post (keynum) VALUES ($keynum)";
$fileLocation = getenv("DOCUMENT_ROOT") . "/num.txt";
$file = fopen($fileLocation,"w");
$content = $keynum;
fwrite($file,$content);
fclose($file);
echo 'Response';
die();
?>
You can achieve what you want using XMLHttpRequest, like this:
function updateData() {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById('num').innerHTML = this.responseText;
}
};
xhttp.open('GET', '/num.php', true);
xhttp.send();
}
setInterval(updateData, 2000);
If you want to refresh the variable without refreshing the page, then you need to use an asynchronous request. It doesn't need to be AJAX, you can use the native XMLHttpRequest() function.
If you want more info: https://developer.mozilla.org/en-US/docs/Web/API/XMLHttpRequest/Synchronous_and_Asynchronous_Requests
or with jquery:
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
setInterval(function(){
$.ajax({url:"num.php", success:function(result){
$("#num").html(result);
}});
}, 3000);
</script>
<textarea id="num"></textarea>
get_nbr.php
<?php
$file = "num.txt"; //Path to your *.txt file
$contents = file($file);
$num = implode($contents);
echo $num;
?>
index.php
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<!---trigger get_nbr() on page load on an infinite loop every two seconds -->
<body onload="setInterval(get_nbr, 2000)">
<script>
function get_nbr() {
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById("num").innerHTML = this.responseText;
}
};
xhttp.open("GET", "get_nbr.php", true);
xhttp.send();
}
</script>
<p id="num"></p>
like this.
let url = ""; //whatever url your requesting.
setInterval(function(){
var x = new XMLHttpRequest();
x.open("GET" , url , true);
x.onreadystatechange = function(){
if(x.readyState == 4 && x.status == 200)
{
document.getElementById("num").innerHTML = x.responseText;
}
}
x.send();
} , 2000);
-- UPDATE , added post --
setInterval(function(){
var x = new XMLHttpRequest();
x.open("POST" , url , true);
x.setRequestHeader("Content-Type" , "application/x-www-form-urlencoded");
x.onreadystatechange = function(){
if(x.readyState == 4 && x.status == 200)
{
document.getElementById("num").innerHTML = x.responseText;
}
}
x.send("postVar1=123");
} , 2000);

Cannot get data passed to a php file using AJAX

I am trying to pass data back to the server and then use the reply to update the browser page.
My code for a SELECT input is as follows;
<select id ="MatchCaptain" name="MatchCaptain" onchange="findTeleNo(this.value)"
<?php
$MC = $_SESSION["MatchCapt"];
player_load($MC);
?>
>
</select>
The script code is as follows;
<script>
function findTeleNo(that){
alert("I am an alert box!" + that);
var xhttp;
if (window.XMLHttpRequest) {
// code for modern browsers
xhttp = new XMLHttpRequest();
} else {
// code for old IE browsers
xhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementById("TeleNo").value = this.responseText;
}
}
};
xhttp.open("GET", "findTeleNo.php?q=" + that, true);
xhttp.send();
</script>
The purpose of the script is to take the value selected in the dropdown (variable "that") and submit it to the php file as variable q.
And the PHP file is as follows;
<?php
$MatchCaptain = $_REQUEST["q"];
$teleNo = "";
$db_handle = mysqli_connect(DB_SERVER, DB_USER, DB_PASS );
$database = "matchmanagementDB";
$db_found = mysqli_select_db($db_handle, $database);
if ($db_found) {
$SQL = "SELECT * FROM `playerstb` ORDER BY `Surname` ASC, `FirstName` ASC";
$result = mysqli_query($db_handle, $SQL);
$ufullName = split_name($MatchCaptain);
while ( $db_field = mysqli_fetch_assoc($result) ) {
$uName = $db_field['FirstName'];
$uName = trim($uName);
$Surname = $db_field['Surname'];
$Surname = trim($Surname);
$fullName = $uName." ".$Surname;
if ($fullName == $ufullName )
{
$teleNo = $db_field['TeleNo'];
break;
}
}
}
echo $teleNo;
function split_name($name) {
$name = trim($name);
$last_name = (strpos($name, ' ') === false) ? '' : preg_replace('#.*\s([\w-]*)$#', '$1', $name);
$first_name = trim( preg_replace('#'.$last_name.'#', '', $name ) );
$ufullName = $first_name." ".$last_name;
return $ufullName;
}
?>
The php file requests the q variable from the url and makes it $MatchCaptain.
This will be a name like Joe Bloggs. The next piece of code connects to a MySQL table to extract players first names surnames and telephone numbers. The first names and surnames are concatenated to form the fullname which is compared with the $MatchCaptainWhen a match is made the variable $teleNo is set to the Telephone Number of that player. The echo statement rerurns the value to the script.
The field id I am trying to update is;
<p><b>Telephone Number: </b> <span id="TeleNo"> <?php echo $_SESSION["TeleNo"]; ?></span></p>
The alert in the script function findTeleNo shows me that I have entered the function but nothing happens after that.
Any help as to how I get this working would be grateful.
I have changed my script to
<script>
function findTeleNo(that){
var xhttp;
if (window.XMLHttpRequest) {
// code for modern browsers
xhttp = new XMLHttpRequest();
} else {
// code for old IE browsers
xhttp = new ActiveXObject("Microsoft.XMLHTTP");
}
xhttp.open("GET", "findTeleNo.php?q=" + encodeURIComponent(that), true);
xhttp.send();
xhttp.onreadystatechange = function() {
if (xhttp.readyState === 4) {
if (xhttp.status === 200) {
// OK
alert('response:'+xhttp.responseText);
document.getElementById("TeleNo").innerHTML = this.responseText;
// here you can use the result (cli.responseText)
} else {
// not OK
alert('failure!');
}
}
};
};
</script>
The response shown by alert('response:'+xhttp.responseText); is correct and the line of code
document.getElementById("TeleNo").innerHTML = this.responseText;
does print the response to the web page.

Use Ajax to update data on page which is read from text file with PHP

I want to update data on my webpage using Ajax. This data is read using PHP script
and I want this function to carry out EVERY 5 seconds. For some reason, this is not happening at all.
My JavaScript:
<script>
function refresh(){
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementClassName("scroll").innerHTML = this.responseText;
}
};
xmlhttp.open("GET", "gm.php?q=" + "<?php echo $mf[0]."-".$mf[1].".txt" ?>", true);
// The PHP variables refer to a specific file
xmlhttp.send();
}
setInterval(refresh,5000);
</script>
My gm.php file:
<?php
$q = $_REQUEST["q"];
$mr=fopen($q, "a+");
$line = fgets($mr);
while (!feof($mr)) {
$line = $line.fgets($mr);
} # while ends
fclose($mr);
echo $line. "<br />";
?>
I figured out that my element selector was wrong as I was using get ElementClassName instead of getElementsByClassName. Also, I hadn't given the element index in the class, due to which the element could not be selected.
Another reason was my usage of quotes within the JavaScript string which included the PHP script.
My JavaScript:
<script>
function refresh(){
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200) {
document.getElementsByClassName("scroll")[1].innerHTML = this.responseText;
}
};
xmlhttp.open("GET", "gm.php?q=" + '<?php echo $mf[0]."-".$mf[1].".txt" ?>', true);
// The PHP variables refer to a specific file
xmlhttp.send();
}
setInterval(refresh,5000);
</script>
My gm.php file:
<?php
$q = $_REQUEST["q"];
$mr=fopen($q, "a+");
$line = fgets($mr);
while (!feof($mr)) {
$line = $line.fgets($mr);
} # while ends
fclose($mr);
echo $line. "<br />";
?>

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