Sending JSON to PHP - php

I'm tring to send a JSON to a PHP page via jQuery, but it doesn't work properly:
json_data = {};
json_data.my_list = new Array ();
$('#table_selected tr').each (function (i) {
json_data.my_list.push ({id:$(this).attr("id")});
});
$.post ("my_page.php", json_data, function (response) {
if (response) alert("success");
else alert("error");
});
<?php
// this is my_page.php
$json = json_decode (stripslashes ($_REQUEST['my_list']), true);
echo var_dump($json);
?>
This returns NULL to my callback, where I'm wrong?

JSON is a string representation of JavaScript objects. You're sending something that looks like this:
{my_list: [{id: 'foo'}, {id: 'bar'}, {id: 'baz'}]}
Which is not JSON. This is JSON:
'{"my_list": [{"id": "foo"}, {"id": "bar"}, {"id": "baz"}]}'
I would recommend using json2.js (more info). This can be facilitated using .serializeArray().

you don't need the echo before var_dump

json_data is a literal with an array inside that you put as parameter to the post, and will be sent as encoded array in the post request to the server.
In my_page.php you may want to look at $_POST array.
UPDATE: Ehm, I re-read your question and I'm not completely sure of what I wrote. What I said applies to GET request, and I believe also to post requests.

Related

Passing JSON object to PHP with jQuery AJAX

I have 3 different JSON objects I want to concatenate and send over to a PHP file with jQuery AJAX. I can retrieve the JSON object in the PHP file, but cannot figure out how to loop through the results.
Here's what I have so far:
//my 3 JSON objects:
var json_obj_1{
"test1_key":"test1_val",
"test2_key":"test2_val",
"test3_key":"test3_val"
}
var json_obj_2{
"test4_key":"test4_val"
}
var json_obj_3{
"json_arr":[
{
"test1":"test2",
"test3":"test4"
}
]
}
//concat these to send over to the PHP file:
var my_json_obj = json_obj_1.concat(json_obj_2);
//I found if I didn't stringify obj_3 they didn't concatenate for some reason
my_json_obj = my_json_obj.concat(JSON.stringify(json_obj_3));
//my_json_obj now looks like this:
{
"test1_key":"test1_val",
"test2_key":"test2_val",
"test3_key":"test3_val"
}
{
test4_key: test4_val
}
{
"json_obj_3":[
{"test1":"test2","test3":"test4"}
]
}
Based on this question: Sending JSON to PHP using ajax, I don't stringify the final JSON object.
Here's the AJAX call to the PHP file:
$.ajax({
url: 'my_php_file.php',
data: {my_json_data: my_json_obj},
type: 'POST',
async: false,
dataType: 'json',
cache:false,
success:function(data, textStatus, jqXHR){
console.log('AJAX SUCCESS');
},
complete : function(data, textStatus, jqXHR){
console.log('AJAX COMPLETE');
}
});
This is what it looks like when retrieved in my PHP file:
echo $_POST['my_json_data'];
//outputs:
{
"test1_key":"test1_val",
"test2_key":"test2_val",
"test3_key":"test3_val"
}
{
test4_key: test4_val
}
{
"json_obj_3":[
{"test1":"test2","test3":"test4"}
]
}
Here's where I run in to problems. I want to be able to loop through this in a foreach. From what I have read (php: loop through json array) I have to decode the JSON object. However when I do this and loop through the results I get: " PHP Warning: Invalid argument supplied for foreach() ".
Even if I stringify the JSON object before sending it over to the PHP file I get the same problem. I have been banging my head against a brick wall for hours with this. Any help will be massively appreciated.
Thanks in advance.
Solved:
I was going wrong when concatenating my JSON objects following this question: Merge two json/javascript arrays in to one array. Instead I just put them together like so:
my_json_obj = '['+json_obj_1+','+json_obj_2+', '+JSON.stringify(json_obj_3)+']';
I then use json_decode in my PHP file which works a treat. http://json.parser.online.fr/ was invaluable in debugging my dodgy JSON. A great tool for JSON beginners.
You should be stringifying the whole object, try the following:
var my_json_obj = json_obj_1;
$.each(json_obj_2, function(key,value){
my_json_obj[key]=value;
});
$.each(json_obj_3, function(key,value){
my_json_obj[key]=value;
});
Ajax request:
data: {my_json_data: JSON.stringify(my_json_obj)},
PHP:
print_r(json_decode($_POST['my_json_data']));
As you say you need to decode the JSON, but your JSON is not well formed so I think the decode function is failing which causes the foreach error. There needs to be a , between objects, there's missing quotes around test4_val and it needs to be inside a singular object/array
You can check your JSON is wellformed at:-
http://json.parser.online.fr/
I think you want it to look more like:-
[{
"test1_key":"test1_val",
"test2_key":"test2_val",
"test3_key":"test3_val"
},
{
"test4_key": "test4_val"
},
{
"json_obj_3":[
{"test1":"test2","test3":"test4"}
]
}]

json_encode returns array as a string when posting data with jquery.get()

Hello I have a problem with my ajax request in jquery.
When I use my get request without sending any data the response is as expected, I receive my array and can access the values:
$.get(
loadUrl,
function(data) {
useReturnData(data);
},
"json"
);
function useReturnData(data){
leftPlayer = data;
alert(leftPlayer[4]);
};
This works as expected and I recieve my value of "528" being my leftPlayer[4] value.
But when I change my request to send a piece of data to php in the request like so:
$.get(
loadUrl,
{ type: "left" })
.done(function(data) {
useReturnData(data);
},
"json"
);
function useReturnData(data){
leftPlayer = data;
alert(leftPlayer[4]);
};
My data received seems to be in string format to javascript.
My alert prints "5" (the 4th character if the array was a string)
When alerting leftPlayer. I find that in the first request in which I send no data the variable is printed as: 355,355,355,355,528,etc...
Whereas in the second request in which I DO send data it prints as:
[355,355,355,355,528,etc...]
Notice the []. It isn't recognised as an array.
The php file it accesses has absolutely no changes in each request, as I am testing at the moment. The data sent isn't even used in the php file at the moment.
Any ideas where I'm going wrong?
I've fixed my problem.
Like what "nnnnnn" said in his comment I'm passing my "json" parameter to the .done() function instead of the $.get() function.
I couldn't seem to get it to correctly view it as JSON though so I used the easiest method:
$.getJSON(
loadUrl,
{ type: "left" },
function(data) {
useReturnData(data);
}
);
function useReturnData(data){
leftPlayer = data;
alert(leftPlayer[4]);
};
Using $.getJSON instead does like what it says and expects JSON to be returned as default.

jQuery AJAX JSON data not sending

I have the below code running to send data as a JSON object
var jdata = JSON.stringify(grid.serialize());
$.ajax({
'type': 'POST',
'url': 'print.php',
'data': jdata, //assuming you have the JSON library linked.
'contentType': "application/json",
'success': function (data) {
alert(data);
},
'error': function (x, y, z) {
alert(x.responseText);
// x.responseText should have what's wrong
}
});
alert(JSON.stringify(grid.serialize()));
Currenty the alert after the ajax function prints
[{"id":"1","col":"1","row":"1","size_y":"1","size_x":"1"},{"id":"2","col":"2","row":"1","size_y":"1","size_x":"1"}]
On the receiving page I am using <?php print_r($_POST) ?> to see what the page is being sent and it keeps outputting
Array
(
)
I must be missing something simple but have been unable to figure out what. Maybe a fresh set of eyes will see a simple mistake I have made.
I think $_POST is only populated if you send the data encoded as x-www-form-urlencoded. So, just assign the JSON string to a key (jQuery takes care of encoding it properly):
'data': {data: jdata}
and remove the 'contentType': "application/json" part.
Then you get the data in PHP with:
$data = json_decode($_POST['data'], true);
Alternatively, get the raw body of the request in PHP and process it: How to retrieve Request Payload
If you are sending JSON to the server, on the back-end grab your JSON using:
json_decode(file_get_contents('php://input'));
It won't be in the $_POST super global.

Parsing PHP/JSON data in Javascript

I'm trying to communicate AJAX, JSON to PHP and then PHP returns some data and I'm trying to parse it with Javascrpt.
From the php, server I return,
echo json_encode($data);
// it outputs ["123","something","and more something"]
and then in client-side,
success : function(data){
//I want the data as following
// data[0] = 123
// data[1] = something
// data[3] = and more something
}
But, it gives as;
data[0] = [
data[1] = "
data[2] = 1
It is reading each character but I want strings from the array, not individual characters. What is happening here? Thanks in advance, I am new to Javascript and JSON, AJAX.
JSON.parse(data) should do the trick.
Set the dataType property of the ajax call to json. Then jQuery will automatically convert your response to object representation.
$.ajax({
url : ...,
data : ...,
dataType : "json",
success : function(json) {
console.log(json);
}
});
Another option is to set headers in PHP so that JQuery understand that you send a JSON object.
header("Content-Type: application/json");
echo json_encode($data);
Check this one... Should Work
success : function(data){
var result = data;
result=result.replace("[","");
result=result.replace("]","");
var arr = new Array();
arr=result.split(",")
alert(arr[0]); //123
alert(arr[1]); //something
alert(arr[2]); //......
}
You did not shown function in which you parse data. But you shoud use
JSON.parse
and if broser does not support JSON then use json polyfill from https://github.com/douglascrockford/JSON-js
dataArray = JSON.parse(dataFomXHR);
I'm not sure if this is what you want but why don't you want php to return it in this format:
{'item1':'123','item2':'something','item3':'and more something'}
Well to achieve this, you'll need to make sure the array you json_encode() is associative.
It should be in the form below
array("item1"=>123,"item2"=>"something","item3"=>"more something");
You could even go ahead to do a stripslashes() in the event that some of the values in the array could be URLs
You could then do a JSON.parse() on the JSON string and access the values
Hop this helps!

Print array from PHP in the jQuery

How can print date and age (in following array) separate by $.ajax()?
php:
$array = array(
'date' => 2011/9/14,
'age' => 48,
);
return $array // this send for ajax call in the jQuery
I want this output by jquery:2011/9/14 & 48
Use $.ajax Methods and setting parameter dataType to JSON for receive data type JSON from PHP file.
Jquery Code:
$.ajax({
url: "getdata.php",
type: "post",
dataType: "json",
success: function(data){
alert("Date:" + data.date + "\n" + "Age:" + data.age);
}
});
if your array data contains string make sure it's closured with quote then make data type JSON with json_encode() function.
PHP Code (getdata.php):
$array= array('date'=>'2011/9/14','age'=>48);
echo json_encode($array);
Echo the encoded array in php page say mypage.php
using
echo json_encode($array);
And use jQuery.getJson in the client side
$.getJSON('mypage.php', function(data) {
alert(data['date']);
alert(data['age']);
});
You need to encode the array as a valid JSON string using the PHP function json_encode. You can then use the jQuery function $.parseJSON to convert it into a JavaScript object. From there you'll be able to do whatever you want with it.
If you do this, you'll end up with an object like:
ajaxDataObj = {
date: '2011/9/14',
age: 48
}
**Edit**
Please see stratton's comment below about using $.getJSON for a more compact solution.
Also, Ben Everard's comment on your original post about using echo rather than return is critical.
You can't just return $array to the browser, the result will be "Array" as string.
YOu have to use return json_encode($array); which returns a string that could be parsed by browser.
If the server-client communication is working alright, then you should do something like this on the client side:
$.ajax({
//configuration...
'success':function(response){
var dateAge = response.date+' & '+response.age;
//put or append the string somewhere.
}
});

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