JavaScript jQuery post:
var animals = {
animalsArray: [],
tripId: <?php echo $_GET['id']; ?>
};
$('.student-check').each(function() {
animals.animalsArray.push($(this).attr('id'));
});
var sendMe = JSON.stringify(animals);
$.post("saveChanges.php", sendMe, function(response) {
console.log(response);
}, "json");
PHP handler:
echo json_encode(print_r($_POST, true));
// Array
// (
// )
Why is the array empty? I'm posting data but the response returns an empty array.
You are encoding the data as JSON, which isn't a format PHP handles natively for form submissions.
Remove var sendMe = JSON.stringify(animals); and pass animals to $.post instead of sendMe. jQuery will encode it using one of the standard formats supported by HTML forms and PHP.
Alternatively see this question for how to get the raw request body.
Also:
echo json_encode(print_r($_POST, true));
json_encode and print_r are both functions that take a data structure and express it as a string. Use one or the other, not both.
Related
I need to get an array generated from a script php. I have Latitude and Longitude for each user in a database.
I take the values from the db with this code (file.php):
$query = "SELECT Latitude, Longitude FROM USERS";
$result=mysql_query($query);
$array=array();
while ($data = mysql_fetch_array($result)) {
$array[]=$data['Latitude'];
$array[]=$data['Longitude'];
}
echo $array;
and I call with ajax with this code:
$.post('./file.php',
function( result ){
alert(result);
});
but even if in the script php the array is correct (if I echo array[25] I obtain the right value) in Javascript I obtain "Undefined".
How can I get the array in correct way??
thanks!
edit: after encoded with json_encode($array); in php and JSON.parse(result) in javascript seems not working.
In the console I have the array, but I can't access to its values. (Array[0] gave me "undefined").
use this
echo json_encode($array);
on server side
and
var arr=JSON.parse(result);
on client side
As Ruslan Polutsygan mentioned, you cen use
echo json_encode($array);
on the PHP Side.
On the Javascript-Side you can simply add the DataType to the $.post()-Function:
$.post(
'./file.php',
function( result ){
console.log(result);
},
'json'
);
and the result-Parameter is the parsed JSON-Data.
You can also set the correct Content-Type in your PHP Script. Then jQuery should automaticly parse the JSON Data returned from your PHP Script:
header('Content-type: application/json');
See
http://api.jquery.com/jQuery.post/
http://de3.php.net/json_encode
You need to convert the php array to json, try:
echo json_encode($array);
jQuery should be able to see it's json being returned and create a javascript object out of it automatically.
$.post('./file.php', function(result)
{
$.each(result, function()
{
console.log(this.Latitude + ":" + this.Longitude);
});
});
I am making an AJAX GET request using jQuery to a PHP file. I want the PHP script to return a JSON object, however, currently it is returning a JSON string. I realise I can use JSON.parse in the jQuery code, however, any experience I have in making an AJAX call to an API a JSON object is returned. I am trying to do the same with the php script however, it is returning a string as opposed to an object.
Does anyone know what the best practice is here, and if the best practise is to return a JSON object how I would do this using PHP?
Please see the code below:
js
$.get('test.php', function(data){
console.log((data));
});
php
<?php
$jsonAnswer = array('test' => 'true');
echo json_encode($jsonAnswer);
In your PHP file, change the content type to application/json.
JS
$.get('/process.php', function(data) {
console.log(data);
} );
PHP
<?php
header( "Content-type: application/json" );
$jsonAnswer = array('test' => 'true');
echo json_encode($jsonAnswer);
Then your console should read Object {test: "true"} rather than just the JSON string.
Add json to the end of your get function to return json
$.get('test.php', function(data){
console.log((data));
},'json');//here
and/or add this header in php
header('Content-Type: application/json');
more info here
Without modifying PHP script you can do:
$.get( "test.php", function( data ) {
var arr = $.parseJSON(data);
console.log(arr);
alert(arr.test);
});
Hello I tried to transfer variable from ajax to php, but php file keeps throwing me the following:
Undefined index: vals in /Applications/XAMPP/xamppfiles/htdocs/fang_sophie/project/sign in-out/bin/readall2.php
Ajax reads like this:
<script>
var var_data = "Hello World";
$.ajax({ url: 'bin/readall2.php',
data: {'vals' : var_data},
type: 'post',
dataType:'json',
success: function(output) {
alert(output);
},
error: function(request, status, error){
alert("Error: Could not delete");
}
});
</script>
Php reads like this:
<?php
session_start();
$hello = '';
$_SESSION['hello'] = $_POST['vals'];
echo($hello);
?>
Why doesn't it work? Please help :)
One problem here is that you're trying to output JSON dataType:'json', where you don't have JSON to start with. Consult my footnotes also.
You need to use a text data type.
dataType:'text',
By the way, this won't echo anything at all (in the alert), since $hello is empty:
session_start();
$hello = '';
$_SESSION['hello'] = $_POST['vals'];
echo($hello);
You (may) want to echo the session array taken from the POST array, which is the logical thing to do:
echo($_SESSION['hello']);
Reference:
http://api.jquery.com/jquery.ajax/
Foonotes:
If by any chance you may be trying to access that (PHP) file directly, or your entire code is in the same file, then you need to use a conditional statement for it.
I.e.:
session_start();
if(!empty($_POST['vals'])){
$hello = '';
$_SESSION['hello'] = $_POST['vals'];
echo($_SESSION['hello']);
}
That, and/or use two separate files.
In regards to JSON; if you really want/need to use it, then set it back to dataType:'json', but use json_encode() for it and replacing echo($_SESSION['hello']); with and assigning the $hello variable to the session array:
$hello = $_SESSION['hello'];
echo(json_encode($hello));
<?php
//first start session
session_start();
//set header to json and UTF-8 encoding
header('Content-Type: application/json;charset=utf-8');
//check if $_POST['vals'] is set first using isset() to prevent notice
//undefined index
if(isset($_POST['vals'])){
echo "value of vals is: ".$_POST['vals'];
}else{
echo "vals not set";
}
?>
In your ajax request, the format of return is expect to be JSON. and you are returning a string.
You just need to add json_encode in your return line of php:
session_start();
$hello = '';
$_SESSION['hello'] = $_POST['vals'];
echo(json_encode($hello));
The correct answer is you are reading the wrong variable:
$hello = '';
$_SESSION['hello'] = $_POST['vals'];
echo($hello);
It should be:
echo $_SESSION['hello'];
If you want the session data. For the undefined index, var_dump out your $_POST variable: var_dump($_POST);
If the $_POST variables do not match, or you get back an empty array, it was never transmitted to the server.
Original wrong answer:
When JQuery has "processData" flag set to false, it doesn't encode the data and requires the user reads it from the php://input stream.
Unencoded JSON is not sent into POST requests. For the quickest fix, try this:
parse_str(file_get_contents("php://input"), $vars);
// This will fill $vars with any data sent over to PHP.
var_dump($vars);
$vars should now be populated with the data you want. If $vars is empty, you are not transmitting the data.
I am trying to send some json data from js to php, and pass it to mongo by REST.
The following outputs json string (that works fine later if I just put it as string in PHP file, please see snippet below).
JS to send json:
var s = JSON.stringify(send); //s contains previous data in arrays, etc
ic(s);
function ic(s){
var ajaxUrl = './iM.php';
$.getJSON(ajaxUrl,
{da: s},
function(data) {
console.log (data);
});
}
in iM.php:
$s = $_GET["da"]; // <-- doesn't work
//$s = '{"r":"pax","c":1,"w":["kiwi","melon"],"g":["cat","dog"]}'; //<-- works fine
$opts = array(
"http" => array(
"method" => "POST",
"header" => "Content-type: application/json",
"content" => $s,
),
);
$context = stream_context_create($opts);
$result = file_get_contents("https://api.mongolab.com/api/1/databases/$db/collections/$collection?apiKey=$key", false, $context);
var_dump($result); // Dumps the response document
At the firefox debugger, I can see the file is actually being called, however No data is added.
error_log file is created:
failed to open stream: HTTP request failed! HTTP/1.1 400 Bad Request
I also tried urlencode($s) in php, still not working.
$db, $collection and $key are defiend in php, no problem there.
What am I missing?
Basically JSON.stringify(send) function is designed in such way that it will make your json into what you are getting.
JSON.stringify(value[, replacer[, space]])
You should use this function properly. read the docs to know more.
Its basically useful if you have input value as JS array or JS object
which can be converted to single string.
You are getting '{/"r/":/"pax/",/"c/":1 in only case if you are trying to stringify a json which already in string format.
these:
var s = ['1','2','3'];
and
var s = "['1','2','3']";
are totally different things.
If you are sending an array or json object you can even send it directly
using the code above.
for example :
send = {"r":"pax","c":1,"w":["kiwi","melon"],"g":["cat","dog"]};
ic(send);
function ic(s){
var ajaxUrl = 'im.php';
$.getJSON(ajaxUrl,
{da: s},
function(data) {
console.log (data);
});
}
make sure to handle array at php side properly.
Like if you want return json, do:
$s = $_GET["da"]; //this will be array.
var jsonObject = json_encode($s);
or you can stringify it there and then provide.
or else just send string and then use json_decode to make it json in php
I am not able to serialize the JSON object "data", shown below.
<script type="text/javascript">
var myObj = {'first_name':{'answers':{'0':'John'}}};
var postdata = {'data':myObj};
$.post("get_note.php", postdata, function(data){
$('#note').text(data);
});
</script>
Following is the code in file get_note.php:
<?php
print_r($_POST['data']);
?>
This results in the following being printed to the #note element.
Array ( [first_name] => )
The array appears to be empty. I was expecting a multidimensional array in the PHP file. Why is it empty?
On the client, you can serialize by doing JSON.stringify() for pure javascript. On the server, you'll need to do a php json_decode() on the string.
So on the client:
var postdata = {'data':JSON.stringify(myObj)};
and on the server:
$myObj = json_decode(htmlspecialchars_decode($_POST['data']),true);
References:
js JSON.stringify(): http://www.json.org/js.html
php json_decode(): http://php.net/manual/en/function.json-decode.php
You could try sending a serialized JSON array and decrypt it in server side.
To serialize JSON array use this:
var my_json_array = { index: 11 };
JSON.stringify(my_json_array);
Then in server side you can convert (decode) it to PHP array like this:
$json = $_POST["my_json_array"];
$my_array = json_decode($json);
So your code would turn in this:
<script type="text/javascript">
var data = {'first_name':{'answers':{'0':'John'}}};
var postdata = {'data':JSON.stringify(data)};
$.post("get_note.php", postdata, function(data){
$('#note').text(data);
});
</script>
and
<?php
print_r(json_decode($_POST['data']));
?>
How it was said, this solution is good for new browsers (with native JSON support) for older ones this solution won`t work.
More about JSON support in browsers you can read here:
http://en.wikipedia.org/wiki/JSON#Native_encoding_and_decoding_in_browsers