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Accessing Ajax Response JSON Data in javascript

I use an AJAX request to get the data from the backend when user select an option from a dropdown menu.
$('#adSpace').change(function () {
var sel_opt = $(this).val();
alert(sel_opt);
var location = null;
var width = null;
var height = null;
$.ajax({
type: "GET",
dataType: 'json',
url: "advertisements-controller.php",
data: {
action: "getDimension",
location: sel_opt
},
success: function (response) {
location = response.banner_location;
alert(location);
},
error: function (xhr) {
alert("error");
}
});
});
Now i'm getting the data from backend in JSON format like below:
[{"banner_location":"category_group_sidebar","banner_width":250,"banner_height":225}]
I want to access the values of banner_location, banner_width, banner_height by assigning those to javascript variables but I'm failing to do it.
Any ideas?

Use this
location = response[0].banner_location;

Your response comes in the form of an array: [...]. That means you can access the first array item by using the index. Also if there are multiple objects you can iterate response with forEach or jQuery's each($(response).each).
response[0].banner_location

response is an array of json. In order to access the json you need to firsr access the index of the array which is done by array[indexNumber] then the key of the json.
In your case it will be response[0].banner_location

Ajax array only returns 1 value?

I am new to PHP and Ajax so please bear with me. I've searched around and found some answers but still am having trouble. I have an array of check box input values. If a user checks an item it is added to my array list. An example would be:
listOfPrograms = [chrome, firefox, sqlworkbench]
I want to send this array list to a PHP script on my server. My current Ajax script is as follows:
function ajaxPostToPhp(listOfPorgrams)
{
$.ajax
({
url: 'script.php',
type: 'post',
data: ("listOfPrograms" : listOfPrograms), // I believe this is where my issues lies as I do not know exactly that this is doing. I have read the PHP documentation. I tried converting to JSON and kept getting a 500 error.
success: function(data)
{
console.log(data);
}
});
}
My PHP script is as folllows:
$myArray = $_Request['listOfPrograms'];
echo $myArray;
This returns only 1 item from the array. I tried setting myArray = [] but I get an undefined index.
Thanks for your help! Sorry for such a noob question.

You need to fix a few things:
1- Javascript array:
var listOfPrograms = ['chrome', 'firefox', 'sqlworkbench'];
2- Ajax Data:
function ajaxPostToPhp(listOfPrograms)
{
myListData = {};
myListData['Programs'] = listOfPrograms;
$.ajax({
url: 'script.php',
type: 'post',
data: myListData,
success: function(data)
{
console.log(data);
}
});
}
3- Php Code:
$myArray = $_POST['Programs'];
var_dump($myArray);

You are passing an array as post parameter but they can only be strings. You should convert the array to a JSON string first. An easy function for that purpose is JSON.stringify()
var listOfPrograms = ["chrome", "firefox", "sqlworkbench"]
// I guess you need strings here
function ajaxPostToPhp(listOfPorgrams) {
$.ajax ({
url: 'script.php',
type: 'post',
// Convert listOfPrograms to a string first
data: ("listOfPrograms" : JSON.stringify(listOfPrograms)),
success: function(data) {
console.log(data);
}
});
}

jquery will kindly turn array values in ajax post data to an array for you. the issue is that in php you can't just echo an array. as a commenter stated, your php file needs to look like
$myArray = $_Request['listOfPrograms'];
echo json_encode($myArray);
also you should consider using $_POST over $_REQUEST

how to send data from one web page to another?

I don't how to ask this question but if their are duplicates send me that. Their are several .php files i have made
content.php, show.php and showFilteredResult.php .
content.php sends the start date and end date to the show.php and it returns the the orderIds which are of that date
$(document).ready(function () {
var srt = $("#cal1Date1").val();
var end = $("#cal1Date2").val();
$.ajax({
url: "http://localhost/show.php",
data: {
srt: srt,
end: end
},
type: "POST",
dataType: "json",
complete: function (response) {
$rtndata = response.responseText;
var dat1a = jQuery.parseJSON($rtndata);
var result = dat1a.OrderID;
console.log(result[0]); // send this result
}
});
});
now I want to send this $result with orderids to showFilteredResult.php where then i can make tables etc.

I'd skip the AJAX and just use request parameters (GET or POST).
cal1Date1 and cal1Date2 are input fields I assume. Wrap them in a form and post the values to a PHP form handler that could handle the lookup and display. No need for the AJAX middle-man here.

Just make a similar Ajax request to showFilteredResult.php I would have them in a separate function.
function showFilteredResult($result){
$.ajax({
url:"http://localhost/showFilteredResult.php",
data: {
result:$result
},
type:"POST",
dataType: "json",
complete:function(response){
$rtndata=response.responseText;
var dat1a=jQuery.parseJSON($rtndata);
var result=dat1a.OrderID;
console.log(result[0]);// do something with the data returned from showFilteredResult.php
}
});
}
and from the request that you have just call that funciton like
... $rtndata=response.responseText;
var dat1a=jQuery.parseJSON($rtndata);
var result=dat1a.OrderID;
console.log(result[0]);// send this result
showFilteredResult(result[0]);
}
});

Instead making another request to server , you have another option to do that. Let's say you get orderId from show.php before sending back , right ? Then you can use this orderId to do what u want such as query which u have written in showFilteredResult.php . then return back to client for final result . In that way you can eliminate the unnecessary http request.

How to access the serialized data in PHP file in the following scenario?

How to access the serialized data in a PHP file in following situation?
The code and the serialized data is as follows:
$(document).ready(function() { $(document).on('click', '#delete_url', function (e) {
e.preventDefault();
var items = new Array();
$("input:checked:not(#ckbCheckAll)").each(function() {
items.push($(this).val());
});
var str = $("#user_filter").serialize();
$.ajax({
type: "POST",
url: "manage_users.php?op=delete_bulk_users&items="+items,
data: str,
dataType: 'json',
success: function(data) {
//var message = data.success_message;
var redirect_link = data.href;
alert(redirect_link);
window.location.href = redirect_link;
}
});
});
});
The data I'm getting in after serialize in str is as follows:
op=group_filter&page=1&from_date=11%2F10%2F2000&social_login=&to_date=11%2F10%2F2013&login_criteria=all&user_name=&user_state=&user_email_id=&user_city=
Now the PHP file(manage_users.php) is as follows:
/*The code is actually one of the switch casees*/
prepare_request();
$request = empty( $_GET ) ? $_POST : $_GET ;
$op = $request['op'];
switch( $op ) {
case "delete_bulk_users":
print_r($request);/*For printing the received array of values after form submission
Here I'm not getting serialized data */
}
Thanks in advance.

The serialize function is intended to be used to create a query string for a URL from a collection of inputs (or an entire form), and will out of necessity encode characters such as / (which denotes a directory in a URL). There's no way to tell .serialize() to convert to the "proper" format because it already is.
If you're using the result of .serialize() as part of an AJAX request it's fine to do that like so:
$.ajax({
url: 'yourpage.php',
data: str, // the string returned by calling .serialize()
... // other options go here
}).done(function(response) {
// do something with the response
});
Your server should handle decoding those characters when it receives the request and provide the correct values to you.
If you're using it for something else you could try using the native JavaScript decodeURIComponent function to convert those encoded characters back, like so:
str = decodeURIComponent(str);
Note that calling decodeURIComponent and then trying to use it for an AJAX request won't work.
For more information on URI encoding take a read through the MDN entry for encodeURIComponent.

Send JavaScript object to web server call via jQuery - what is the correct way?

I'm trying to send JSON data to my web server via jQuery and I'm running into an error.
Uncaught TypeError: Cannot use 'in' operator to search for 'context' in {"id":45,"isRead":true}
code I am testing:
var obj = {};
obj.id = 45;
obj.isRead = true;
var data = JSON.stringify(obj);
var url = "/notification/read"
$.ajax(url, data, 'application/json', function() {
// code remove notification from the DOM
});
});
Is there a better or more correct way to do this? Not sure if I'm getting the params right on the $.ajax call either.
UPDATE
code I got to work
var obj = {
id: 45,
isRead: true
};
var json = JSON.stringify(obj);
var url = "/notification/read"
$.ajax({ url: url,
type:'POST',
contentType: 'application/json',
data: json,
success: function(data, textStatus) {
// do stuff
}
});
My server was expecting JSON data POSTed as application/json. So was I wrong in thinking I needed all these variables? without these it was sent as a GET and was application/x-www-form-urlencoded. Without the stringify it also didn't work.

You are passing too many arguments to the ajax function: http://api.jquery.com/jQuery.ajax/
Also, the JSON.stringify call is not necessary, jQuery will take care of that for you.
var obj = {
'id':45,
'isRead':true
};
$.ajax({
url: "/notification/read",
data: obj,
success: function(data, textStatus){
/* code here */
}
});

$.ajax(url, obj);
You need to send an object as second param
{success: success, data: data}

Documentation is here:
http://api.jquery.com/jQuery.ajax/
You have to pass parameters as one object, not multiple ones