Develop Reference

PHP not able to read JSON but writes extra lines in SQL

I have an HMTL form with 3 fields on it, Firstname, Lastname and image upload file. When submit is pressed it calls the following JS script.
//main function to be called on submit
function processData() {
var firstName = document.querySelector('#first-name'),
lastName = document.querySelector('#last-name'),
imageUser = document.querySelector('#image-user');
var formSubmitData = {
'firstName': firstName.value,
'lastName': lastName.value,
'imageUser': imageUser.value
};
var dataString = JSON.stringify(formSubmitData);
if (navigator.onLine) {
sendDataToServer(dataString);
} else {
saveDataLocally(dataString);
}
firstName.value = '';
lastName.value = '';
imageUser.value = '';
}
//called on submit if device is online from processData()
function sendDataToServer(dataString) {
var myRequest = new XMLHttpRequest();
//new code added so data is sent to server
//displays popup message - data sent to server
myRequest.onreadystatechange = function() {
if (myRequest.readyState == 4 && myRequest.status == 200) {
console.log('Sent to server: ' + dataString + '');
window.localStorage.removeItem(dataString);
} else if (myRequest.readyState == 4 && myRequest.status != 200) {
console.log('Server request could not be completed');
saveDataLocally(dataString);
}
}
myRequest.open("POST", "write_test.php", true);
//Send the proper header information along with the request
myRequest.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
myRequest.send(dataString);
alert('Sent: ' + dataString + ''); //remove this line as only for example
}
As you will see it sends a POST request to the php page. The "datastring" is encoded as JSON.
I use the following PHP code to send the data to the SQL server, but all it does is create a blank record with no data but it does create a new record.
<?php
//TRYING NEW CODE TO EXTRACT DATA FROM dataString
$json = json_decode(file_get_contents("php://input"), true);
$data = json_decode($json, true);
echo '<pre>' . print_r($data, true) . '</pre>';
// INSERT into your contact table.
$sql="INSERT INTO contacts (firstName, lastName)VALUES('$firstName','$lastName')";
How do I get it to create records in SQL with data that has been submitted from the form??

I have no final solution as I don't have the form code. Hope you are ready to learn.
I'm worried about user image - don't send any image for testing, but a string (like path) or nothing, please.
js - change for double quotes:
var formSubmitData = {
"firstName" : firstName.value,
"lastName" : lastName.value,
"imageUser" : imageUser.value
};
php - leave only this
<?php
$data = json_decode(file_get_contents("php://input")); // test only version
print_r($data); // test only version
/*
and close the rest as a comment - SQL is fine, don't worry
$data = json_decode(file_get_contents("php://input",true)); // final ver
echo print_r($data, true); // final ver
...
*/
If you receive the right output, delete the trial version and good luck.
If not - go back to var formSubmitData to the values on the right - they are so naked ... without any quotes
And of course, take care of security (injection) and order, set the required at the inputs - you don't need empty submits

POST with Javascript AJAX

I am currently writing some poll software and, even though it works fine, I am having difficulties getting some of my javascript to work. I have a button labelled "Add New Option" which, when clicked, will call the following javascript function:
function newoption()
{
var option = "";
while((option.length < 1)||(option.length > 150))
{
var option = prompt("Please enter the option value... ").trim();
}
var add = confirm("You entered " + option + ", are you sure?");
if(add==1)
{
var code = window.location.href.length;
var poll = prompt("Which poll are you adding this to?", window.location.href.substring(code - 5, code));
var xhttp = new XMLHttpRequest();
xhttp.onreadystatechange = function() {
if (this.readyState == 4 && this.status == 200)
{this.responsetext = option;}};
xhttp.open("POST", "../special/new.php", true);
xhttp.send("poll=" + poll + "&opt=" + option);
}
else
{
alert("OK... try again");
}
}
The page it posts to simply has a function to add the option to the poll which the user supplies the code for (it automatically gets this from the end of the URL) but the problem is that, when I refresh the page, the list of options is not updated which makes me think it isn't being added to the database but the function to add new options works on when the poll is created. Is there something I'm doing wrong?
The code for new.php is:
<?php require("internal/index.php");
$option = string_format($conection, $_POST["opt"], 1)
$poll =(int) $_POST["poll"];
if($poll&&$option)
{
new_poll_option($connection, $poll, $option);
}
?>

From what you wrote I understand that the code works until you refresh the page. That means that you don't check the Ajax response and just insert some HTML which will last until you refresh the page.
You need to look in your database if the items was created. If it is created then maybe you need to delete the browser cache (you can do that from the Network tab in DevTools in Chrome).
If the items was not insert in the database then you need to debug or just echo the message from the insert function that you used.
You can also use a form and not use Ajax if you will refresh the page anyway in a few moments.

Duplicate JavaScript and php problems

I recently notice that I have a duplicate line on the table, when the device is spinning or calling someone on this davay at the time of pressing the 'save' button. On the lines of UserRealTime I see that the interval is a duplicate of 5-6 milliseconds.
How to avoid duplicates using javascript or jQuery. For example, check the connection of the device to the Internet?
ajax.php
<?php
if (isset($_GET['d1']) && isset($_GET['d2']))
{
$conn=connSQL();
$query = "insert into doorname(d1, d2, UserRealTime) values ('".$_GET['d1']."','".$_GET['d2']."', getdate())";
$rs=$conn->execute($query);
$rs->Close();
$conn->Close();
}
?>
JavaScript
<script>
var httpObject = null;
function getHTTPObject()
{
if (window.ActiveXObject)
{
return new ActiveXObject("Microsoft.XMLHTTP");
}
else if(window.XMLHttpRequest)
{
return new XMLHttpRequest();
}
else
{
return null;
}
}
function Inter()
{
httpObject = getHTTPObject();
if (httpObject != null)
{
var d1=document.getElementById('d1').value;
var d2=document.getElementById('d2').value;
if (d1=="" || d2=="")
{
alert("sorry!!!");
}
else
{
httpObject.open("GET", "ajax.php?d1="+d1+"&d2="+d2, true);
httpObject.send(null);
httpObject.onreadystatechange = InterSet;
}
}
}
function InterSet()
{
if(httpObject.readyState == 4)
{
var data=httpObject.responseText;
alert("Good!!!");
}
}
</script>

This way of approach it is not a suggested practice. However, just to work around the problem here is one way of handling general duplicate DB entries.
Generate one random Token on the client side for every successful server side insert. Discard the Token on client side once the server confirms the successful insert. Following is an example:
1) Generate a random Token on the client side, like so
Generate random string/characters in JavaScript
var tokenOnClientSide = makeid();
2) Attach the generated Token to Ajax Params:
httpObject.open("GET", "ajax.php?d1="+d1+"&d2="+d2+"&token="+token, true);
3) Server side: Look if the Token already exists
<?php
if (isset($_GET['d1']) && isset($_GET['d2']) && isset($_GET['token']))
{
$query = sprintf("SELECT * FROM token_table WHERE token = '%s'", $_GET['token']);
$rs=$conn->execute($query);
if (mysql_num_rows($res) == 0) {
// carry on with insert and return success message
.....
// now store the token permanently
$query = "insert into token_table(token, time_of_exec) values ('".$_GET['token']."', getdate())";
$rs=$conn->execute($query);
}
4) Finally, unset the global token on client side
tokenOnClientSide = "";
Hope that one gets a basic idea of handling duplicates.

send content of dynamically changing div to database

I have a Server Send Event working and updating a webpage. I then assign the contents of the div receiving the SSE to a var so as to send it to a php file to insert into a database. The div's data is constantly changing in sseReceiving.php page, but how to send it and it's changing values to the database dynamically. Now it is only sending the div content to the database when the page is re-submitted. How to do it continually?
sseTriggering.php
header('Content-Type: text/event-stream');
header('Cache-Control: no-cache');
//generate random number for demonstration
$new_data = rand(0, 1000);
//echo the new number
//echo "data: New random number:". $new_data. "\n\n";
echo "data:".$new_data."\n\n";;
flush();
sseReceiving.php
<body>
<div id="serverData">Here is where the server sent data will appear</div>
<script type="text/javascript">
//check for browser support
if(typeof(EventSource)!=="undefined") {
//create an object, passing it the name and location of the server side script
var eSource = new EventSource("sseTriggering.php");
//detect message receipt
eSource.onmessage = function(event) {
//write the received data to the page
document.getElementById("serverData").innerHTML = event.data;
var MyDiv = document.getElementById("serverData").innerHTML;
window.location.href = "findpair.php?pair=" + MyDiv;
};
}
</script>
</body>
findpair.php
$pair = $_GET['pair'];
$qX = "UPDATE product SET prod_name = '$pair' WHERE id = 1";
$rrr = mysqli_query ($dbc, $qX) or trigger_error("Query: $q\n<br />MySQL Error: " . mysqli_error($dbc));
I have researched this issue at the links below and some have helped me get it to the stage it is at now.
http://www.coderslexicon.com/the-basics-of-passing-values-from-javascript-to-php-and-back/
send javaScript variable to php variable
Get content of a DIV using JavaScript
Detect element content changes with jQuery
I have also put header('Refresh: 5'); in the php part of the various files and no change.

You should be able to send the request via AJAX for your main function which will allow the sse events to come to your client and then go to your findpair.php function.
if(typeof(EventSource)!=="undefined") {
//create an object, passing it the name and location of the server side script
var eSource = new EventSource("sseTriggering.php");
//detect message receipt
eSource.onmessage = function(event) {
//write the received data to the page
document.getElementById("serverData").innerHTML = event.data;
//Send AJAX request.
var xmlhttp = new XMLHttpRequest();
xmlhttp.onreadystatechange = function() {
if (xmlhttp.readyState == XMLHttpRequest.DONE ) {
if (xmlhttp.status == 200) {
//Do something with 'xmlhttp.responseText' if you want.
}
else if (xmlhttp.status == 400) {
alert('There was an error 400');
} else {
alert('something else other than 200 was returned');
}
}
};
xmlhttp.open("GET", "findpair.php?pair=" + event.data, true);
xmlhttp.send();
};
}
More info here on submitting AJAX requests with javascript.

fetching xml data into a div via ajax and javascript

Building a chat app and I am trying to fetch all logged in user into a div with ID name "chat_members". But nothing shows up in the div and I have verified that the xml file structure is correct but the javascript i'm using alongside ajax isn't just working.
I think the problem is around the area of the code where I'm trying to spool out the xml data in the for loop.
XML data sample:
<member>
<user id="1">Ken Sam</user>
<user id="2">Andy James</user>
</member>
Javascript
<script language="javascript">
// JavaScript Document
var getMember = XmlHttpRequestObject();
var lastMsg = 0;
var mTimer;
function startChat() {
getOnlineMembers();
}
// Checking if XMLHttpRequest object exist in user browser
function XmlHttpRequestObject(){
if(window.XMLHttpRequest){
return new XMLHttpRequest();
}
else if(window.ActiveXObject){
return new ActiveXObject("Microsoft.XMLHTTP");
} else{
//alert("Status: Unable to launch Chat Object. Consider upgrading your browser.");
document.getElementById("ajax_status").innerHTML = "Status: Unable to launch Chat Object. Consider upgrading your browser.";
}
}
function getOnlineMembers(){
if(getMember.readyState == 4 || getMember.readyState == 0){
getMember.open("GET", "get_chat.php?get_member", true);
getMember.onreadystatechange = memberReceivedHandler;
getMember.send(null);
}else{
// if the connection is busy, try again after one second
setTimeout('getOnlineMembers()', 1000);
}
}
function memberReceivedHandler(){
if(getMember.readyState == 4){
if(getMember.status == 200){
var chat_members_div = document.getElementById('chat_members');
var xmldoc = getMember.responseXML;
var members_nodes = xmldoc.getElementsByTagName("member");
var n_members = members_nodes.length;
for (i = 0; i < n_members; i++) {
chat_members_div.innerHTML += '<p>' + members_nodes[i].childNodes.nodeValue + '</p>';
chat_members_div.scrollTop = chat_members_div.scrollHeight;
}
mTimer = setTimeout('getOnlineMembers();',2000); //Refresh our chat members in 2 seconds
}
}
}
</script>
HTML page
<body onLoad="javascript:startChat();">
<!--- START: Div displaying all online members --->
<div id="chat_members">
</div>
<!---END: Div displaying all online members --->
</body>
I'm new to ajax and would really appreciate getting help with this.
Thanks!

To troubleshoot this:
-- Use an HTTP analyzer like HTTP Fiddler. Take a look at the communication -- is your page calling the server and getting the code that you want back, correctly, and not some type of HTTP error?
-- Check your IF statements, and make sure they're bracketed correctly. When I see:
if(getMember.readyState == 4 || getMember.readyState == 0){
I see confusion. It should be:
if( (getMember.readyState == 4) || (getMember.readyState == 0)){
It might not make a difference, but it's good to be absolutely sure.
-- Put some kind of check in your javascript clauses after the IF to make sure program flow is executing properly. If you don't have a debugger, just stick an alert box in there.

You must send the xmlhttp request before checking the response status:
function getOnlineMembers(){
getMember.open("GET", "get_chat.php?get_member", true);
getMember.onreadystatechange = memberReceivedHandler;
getMember.timeout = 1000; //set timeout for xmlhttp request
getMember.ontimeout = memberTimeoutHandler;
getMember.send(null);
}
function memberTimeoutHandler(){
getMember.abort(); //abort the timedout xmlhttprequest
setTimeout(function(){getOnlineMembers()}, 2000);
}
function memberReceivedHandler(){
if(getMember.readyState == 4 && getMember.status == 200){
var chat_members_div = document.getElementById('chat_members');
var xmldoc = getMember.responseXML;
var members_nodes = xmldoc.documentElement.getElementsByTagName("member");
var n_members = members_nodes.length;
for (i = 0; i < n_members; i++) {
chat_members_div.innerHTML += '<p>' + members_nodes[i].childNodes.nodeValue + '</p>';
chat_members_div.scrollTop = chat_members_div.scrollHeight;
}
mTimer = setTimeout('getOnlineMembers();',2000); //Refresh our chat members in 2 seconds
}
}
To prevent caching response you can try:
getMember.open("GET", "get_chat.php?get_member&t=" + Math.random(), true);
Check the responseXML is not empty by:
console.log(responseXML);
Also you might need to select the root node of the xml response before selecting childNodes:
var members_nodes = xmldoc.documentElement.getElementsByTagName("member"); //documentElement selects the root node of the xml document
hope this helps