Communication between JavaScript, PHP and MySQL - javascript

I'm trying to learn JavaScript to code for Cordova.
I read many tutorials, but none of them helped me with the folowing problem.
My cordova app is for testing very simple. Just a textbox and 2 buttons. Both Buttons calls a PHP script on my server. One button sends data to the PHP script to insert the value of the textfield in a MySQL database, the second button calls the same script and should write the values of the database to my cordova app.
Here is my
<?PHP
$response = array();
require_once __DIR__ . '/db_config.php';
$db_link = mysqli_connect (
DB_SERVER,
DB_USER,
DB_PASSWORD,
DB_DATABASE
);
mysqli_set_charset($db_link, 'utf8');
if (!$db_link)
{
die ('keine Verbindung '.mysqli_error());
}
if(isset($_POST['action']) && $_POST['action'] == 'insert'){
$name = $_POST['name'];
$sql = "INSERT INTO test.testTable (name) VALUES ('$name')";
$db_erg = mysqli_query($db_link, $sql);
if (!$db_erg){
echo "error";
}else{
echo "ok";
}
}
if(isset($_POST['action']) && $_POST['action']=='read'){
$sql = "SELECT * FROM testTable";
$db_erg = mysqli_query( $db_link, $sql );
if (!$db_erg )
{
$response["success"] = 0;
$response["message"] = "Oops!";
echo json_encode($response);
die('Ungültige Abfrage: ' . mysqli_error());
}
while ($zeile = mysqli_fetch_array( $db_erg, MYSQL_ASSOC))
{
//$response["success"] = $zeile['pid'];
//$response["message"] = $zeile['name'];
$response[]=$zeile;
}
echo json_encode($response);
mysqli_free_result( $db_erg );
}
?>
and here are my 2 functions in the cordova app:
function getNameFromServer() {
var url = "appcon.php";
var action = 'read';
$.getJSON(url, function (returnedData) {
$.each(returnedData, function (key, value) {
var id = value.pid;
var name = value.name;
$("#listview").append("<li>" + id + " - " + name) + "</li>";
});
});
}
function sendNameToServer() {
console.log("sendNameToServer aufgerufen");
var url2send = "appcon.php";
var name = $("#Name").val()
var dataString = name;
console.log(dataString);
if ($.trim(name).length>0) {
$.ajax({
type: "POST",
url: url2send,
data: { action: 'insert', name: dataString },
crossDomain: true,
cache: false,
beforeSend: function () {
console.log("sendNameToServer beforeSend wurde aufgerufen");
},
success: function (data) {
if (data == "ok") {
alert("Daten eingefuegt");
}
if (data == "error") {
alert("Da ging was schief");
}
}
});
}
}
My Questions/Problems:
The sendNameToServer funtion works in that case, that the data will be inserted in my Database. But I never get the alert (the success: never called).
How can I pass "action = read" to the PHP script in the getNameFromServer() function?
The third question is a bit off topic, but is this art of code "save" or is it simple to manipulate the data between the cordova app and the server? What's the better way or how can I encrypt the transmission?

Here is one part answer to your question.
$.getJSON has a second optional parameter data that can be an object of information you want to pass to your script.
function getNameFromServer() {
$.getJSON("appcon.php", { action: 'read' }, function (returnedData) {
$.each(returnedData, function (key, value) {
var id = value.pid;
var name = value.name;
$("#listview").append("<li>" + id + " - " + name) + "</li>";
});
});
}
Edit: Since you are using $.getJSON(), the request method is a GET, which means you have to use $_GET in your third if statement in your PHP script.
if(isset($_GET['action']) && $_GET['action'] == 'read'){

Related

Ajax doesn't do anything when php connected to database

I'm trying to establish a simple connection between Javascript and my database using ajax and PHP. Javascript is supposed to receive a name from an HTML form, modify it and post it to PHP to check whether the name is already in the database and return true/ false back to javascript for further use.
Everything works fine as long as I don't add the part of code that connects to the database. Calling only the PHP file in Chrome also works and it will correctly print true or false.
As soon as I connect both together, nothing works. Neither success nor error will execute any of the code inside their functions.
JS1 + PHP1: Nothing happens
JS1 + PHP2: Correctly shows result in Alert1 and Alert2
PHP1 alone: Correctly prints either true or false
JS1
var boo = false;
if(str.length > 1) boo = true;
if (boo)
$.ajax ({
url: 's5Check.php',
type: 'post',
data: { str : str },
success: function( result ) {
alert(result); //Alert1
if(result != false){
boo = false;
alert(str + " already exists!"); //Alert2
} else {
boo = true;
alert(str + " doesn't exist!"); //Alert3
}
},
error: function( e ) {
alert("Error: " + e); //Alert4
}
});
PHP1
<?php
if (isset($_POST['str'])) {
$con = mysqli_connect("localhost","root","","dbtest");
$temp = mysqli_real_escape_string($con, $_POST['str']);
$check = "SELECT id FROM handle WHERE name = '$temp'";
$result = $con -> query($check);
if($result->num_rows > 0) {
echo true;
} else{
echo false;
}
} else{
echo "error";
}
?>
PHP2
<?php
echo $_POST['str'];
?>
Thanks.
echo true will output 1. echo false will output nothing. You're not checking for either of these in your success function.
Using JSON is a simple solution to this, and allows for easy enhancement to more complex results.
JS:
$.ajax({
url: 's5Check.php',
type: 'post',
data: {
str: str
},
dataType: 'json',
success: function(result) {
alert(result); //Alert1
if (result === false) {
boo = false;
alert(str + " already exists!"); //Alert2
} else if (result === true) {
boo = true;
alert(str + " doesn't exist!"); //Alert3
} else if (result === "error") {
alert("Error");
} else {
alert("Unknown problem");
}
},
error: function(jqXHR, txtStatus, e) {
alert("Error: " + e); //Alert4
}
});
PHP:
<?php
if (isset($_POST['str'])) {
$con = mysqli_connect("localhost","root","","dbtest");
$check = "SELECT id FROM handle WHERE name = ?";
$stmt = $con->prepare($check);
$stmt->bind_param("s", $_POST['str']);
$result = $stmt->execute();
$response = $result->num_rows > 0;
} else{
$response = "error";
}
echo json_encode($response);
?>

Is there something special about the variables that are passed via AJAX?

I am trying to access a database and delete a review of a user, I have a method that I pass the user's ID and the ID of the review. This method functions properly using both the SQL command as well as when I call hard-coded variables, however, when I pass the code via AJAX my code says it completed successfully but does not actually do anything. Is there something special about the variables that are passed via AJAX?
This is my method:
public function deleteRating($userid, $reviewID)
{
echo "this is idUsers(IdUsers) = ".$userid." this is reviewID (ID)".$reviewID;
$conn = $this->connect("ratings");
$sql = "DELETE FROM ratedmovies WHERE IdUsers=? AND ID=?";
if(!$stmt = $conn->prepare($sql))
{
echo "False";
}
else
{
$stmt->bind_param("ss", $userid, $reviewId);
if(!$stmt->execute())
{
echo "Failed to delete";
}
else
{
echo "Sucessfull Deletion";
}
}
}
This is the code that calls the method:
<?php
session_start();
include "../Model/Includes/autoLoadCont.inc.php";
$reviews = new Review;
$ratingID = json_decode($_POST['ratingID']);
$user = $_SESSION['userId'];
$reviews->deleteRating($user, $ratingID);
?>
and this is the ajax that calls that function:
var deleteBtns = document.querySelectorAll(".deleteRating");
deleteBtns.forEach(function(button)
{
button.addEventListener("click" , function()
{
$.ajax({
type: "POST",
url: "Controller/deleteReview.php",
data: {ratingID:button.id},
success: function(result)
{
alert(result);
}
});
});
button.id;
});

Ajax not submitting $_Post

I have this section of code that is suppose to get the Values of the input fields and then add them to the database. The collection of the values works correctly and the insert into the database works correctly, I am having issue with the data posting. I have narrowed it down to the data: and $__POST area and im not sure what I have done wrong.
JS Script
$("#save_groups").click( function() {
var ids = [];
$.each($('input'), function() {
var id = $(this).attr('value');
//Put ID in array.
ids.push(id);
console.log('IDs'+ids);
});
$.ajax({
type: "POST",
url: "inc/insert.php",
data: {grouparray: ids },
success: function() {
$("#saved").fadeOut('slow');
console.log('Success on ' + ids);
}
});
});
PHP Section
<?php
include ('connect.php');
$grouparray = $_POST['grouparray'];
$user_ID = '9';
$sql = "INSERT INTO wp_fb_manager (user_id, group_id) VALUES ($user_ID, $grouparray)";
$result=mysql_query($sql);
if ($result === TRUE) {
echo "New records created successfully";
} else {
echo "Error: " . $sql . "<br>" . mysql_error();
}
?>
You cannot send an array trough an ajax call.
First, use something like:
var idString = JSON.stringify(ids);
And use it: data: {grouparray: idString },
On the PHP side:
$array = json_decode($_POST['grouparray']);
print_r($array);

Ajax login issues

I'm having issues with an Ajax login function. There was another question similar to mine that I was able to find but it proved no use.
I have no idea what is the issue, this works on another program as well with no issues, hopefully someone can see my mistake
From testing I think the issue is in the "checkLogIn" function because when I run the application the alert within the function shows
Ajax:
$("#checkLogIn").click(function()
{
$.ajax({
type: 'POST',
contentType: 'application/json',
url: rootURL + '/logIn/',
dataType: "json",
data: checkLogIn(),
})
.done(function(data)
{
if(data == false)
{
alert("failure");
}
else
{
alert("Success");
$.mobile.changePage("#page");
}
})
.always(function(){})
.fail(function(){alert("Error");});
});
function checkLogIn()
{
alert();
return JSON.stringify({
"userName": $("#enterUser").val(),
"password": $("#enterPass").val(),
});
}
I'll also include the PHP but the PHP works 100% after testing it.
PHP:
$app->post('/logIn/', 'logIn');
function logIn()
{
//global $hashedPassword;
$request = \Slim\Slim::getInstance()->request();
$q = json_decode($request->getBody());
//$hashedPassword = password_hash($q->password, PASSWORD_BCRYPT);
$sql = "SELECT * FROM users where userName=:userName AND password=:password";
try {
$db = getConnection();
$stmt = $db->prepare($sql);
$stmt->bindParam("userName", $q->userName);
$stmt->bindParam("password", $q->password);
$stmt->execute();
//$row=$stmt->fetch(PDO::FETCH_ASSOC);
//$verify = password_verify($q->password, $row['password']);
$db = null;
//if($verify == true)
//{
// echo "Password is correct";
//}
//else
// echo "Password is incorrect";
echo "Success";
} catch (PDOException $e) {
echo $e->getMessage();
}
}
I have commented out any and all hashing until I can get this working properly
There is no problem with the ajax script. From my assumption you always get Error alert. That is because you added dataType: "json", which means you are requesting the response from the rootURL + '/logIn/' as json Object. But in the php you simply echoing Success as a plain text. That makes the ajax to get into fail function. So, You need to send the response as json. For more details about contentType and datatype in ajax refer this link.
So you need to change echo "Success"; to echo json_encode(array('success'=>true)); in the php file. Now you'll get Success alert. Below I added a good way to handle the json_encoded response in the php file.
$app->post ( '/logIn/', 'logIn' );
function logIn() {
global $hashedPassword;
$request = \Slim\Slim::getInstance ()->request ();
$q = json_decode ( $request->getBody () );
$hashedPassword = password_hash($q->password, PASSWORD_BCRYPT);
$sql = "SELECT * FROM users where userName=:userName";
try {
$db = getConnection ();
$stmt = $db->prepare ( $sql );
$stmt->bindParam ( "userName", $q->userName );
$stmt->execute ();
$row=$stmt->fetch(PDO::FETCH_ASSOC);
$verify = false;
if(isset($row['password']) && !empty($row['password']))
$verify = password_verify($hashedPassword, $row['password']);
$db = null;
$response = array();
$success = false;
if($verify == true)
{
$success = true;
$response[] = "Password is correct";
}
else
{
$success = false;
$response[] = "Password is incorect";
}
echo json_encode(array("success"=>$success,"response"=>$response));
} catch ( PDOException $e ) {
echo $e->getMessage ();
}
}
And I modified the ajax code. There I showed you how to get the response from the json_encoded Object.
$("document").ready(function(){
$("#checkLogIn").click(function()
{
var post_data = JSON.stringify({
"userName": $("#enterUser").val(),
"password": $("#enterPass").val(),
});
$.ajax({
type: 'POST',
contentType: 'application/json',
url: rootURL + '/logIn/',
dataType: "json",
data: post_data,
})
.done(function(data)
{
// data will contain the echoed json_encoded Object. To access that you need to use data.success.
// So it will contain true or false. Based on that you'll write your rest of the code.
if(data.success == false)
{
var response = "";
$.each(data.response, function(index, value){
response += value;
});
alert("Success:"+response);
}
else
{
var response = "";
$.each(data.response, function(index, value){
response += value;
});
alert("Failed:"+response);
$.mobile.changePage("#page");
}
})
.always(function(){})
.fail(function(){alert("Error");});
});
});
Hope it helps.

PHP Ajax returning HTML twice

I have a PHP/Ajax function that returns a list of countries with the given characters in a textbox. Ofcourse Ajax updates this list everytime the textbox gets edited.
Index.PHP calls all the other files, classes and HTML. But when the textbox gets updated, Ajax sends a POST variable to index.PHP because this is where the Search.PHP file with the class name SearchEngine gets called. But because he sends this to the index.php everything keeps getting reloaded and the HTML will be returned twice.
Index.php
<?php
require_once("cgi_bin/connection.php");
require_once("Database_Handler.Class.php");
require_once("HTML_Page.Class.php");
require_once("search.php");
$hostname_conn = "localhost";
$database_conn = "ajax";
$username_conn = "root";
$password_conn = "";
$db = new DatabaseHandler();
$conn = $db->openConnection($hostname_conn, $username_conn, $password_conn, $database_conn);
$IndexPage = new page();
echo $IndexPage->render();
$SearchEngine = new SearchEngine($conn);
?>
Please ignore the poor and unsecure database connection. I am currently transforming all my code to PDO and refining it but that is for later.
Search.PHP
<?php
class SearchEngine{
private $html;
public function __construct($conn){
$this->html = '<li class="result">
<h3>NameReplace</h3>
<a target="_blank" href="ULRReplace"></a>
</li>';
if (isset($_POST["query"])) {
$search_string = $_POST['query'];
}
//$search_string = mysql_real_escape_string($search_string);
if (strlen($search_string) >= 1 && $search_string !== ' ') {
$query = 'SELECT * FROM country WHERE name LIKE "%' . $search_string . '%"';
$result = $conn->prepare($query);
$result->execute();
$result_array = $result->fetchAll();
foreach ($result_array as $result) {
$display_name = preg_replace("/" . $search_string . "/i", "<b>" . $search_string . "</b>", $result['name']);
$display_url = 'sadf';
$output = str_replace('NameReplace', $display_name, $this->html);
$output = str_replace('ULRReplace', $display_url, $output);
echo($output);
}
}
}
}
?>
And as final the Javascript
$(document).ready(function() {
function search() {
var query_value = $('input#search').val();
$('b#search-string').html(query_value);
if(query_value !== ''){
$.ajax({
type: "POST",
url: "index.php", //Referring to index.php because this is where the class SearchEngine is called
data: { query: query_value },
cache: false,
success: function(html){
$("ul#results").html(html);
}
});
}
return false;
}
$("input#search").keyup(function() {
clearTimeout($.data(this, 'timer'));
var search_string = $(this).val();
if (search_string == '') {
$("ul#results").fadeOut();
$('h4#results-text').fadeOut();
}
else {
$("ul#results").fadeIn();
$('h4#results-text').fadeIn();
$(this).data('timer', setTimeout(search, 100));
};
});
});
note: HTML is being returned from the "page" class called inside Index.php
How do i not let everything get called twice?
Thank you,
EDIT: A new file was suggested where i direct the ajax url to AutoComplete.php
AutoComplete.PHP
Please explain what should be in the file and why. I am clueless.
Basically, just add a parameter to your Ajax call to tell the index.php its being called by Ajax, and then wrap an if-statement around the two lines that print out your actual index page:
if(!isset($_REQUEST['calledByAjax']))
{
$IndexPage = new page();
echo $IndexPage->render();
}
and in your Ajax call:
data: { query: query_value, calledByAjax: 'true' },
Or make another php page, like ajaxsearch.php that's the same as your index.php but lacking those two lines, and call that in your Ajax call.
First thing (this is a sample, not tested yet)
autocomplete.php
<?php
$search_string = $_POST['query'];
$query = 'SELECT * FROM country WHERE name LIKE "%' . $search_string . '%"';
$result = $conn->prepare($query);
$result->execute();
$result_array = $result->fetchAll();
foreach ($result_array as $result) {
$display_name = preg_replace("/" . $search_string . "/i", "<b>" . $search_string . "</b>", $result['name']);
$display_url = 'sadf';
$output = str_replace('NameReplace', $display_name, $this->html);
$output = str_replace('ULRReplace', $display_url, $output);
}
echo($output);
?>
autocomplete.js
function search() {
var query_value = $('input#search').val();
$('b#search-string').html(query_value);
if(query_value !== ''){
$.ajax({
type: "POST",
url: "autocomplete.php", //Here change the script for a separated file
data: { query: query_value },
cache: false,
success: function(html){
$("ul#results").html(html);
}
});
}
return false;
}
$("input#search").keyup(function() {
clearTimeout($.data(this, 'timer'));
var search_string = $(this).val();
if (search_string == '') {
$("ul#results").fadeOut();
$('h4#results-text').fadeOut();
} else {
$("ul#results").fadeIn();
$('h4#results-text').fadeIn();
search(); // call the function without setTimeout
}
});
});
Have luck :)

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