I am trying to parse a response of a string which is a json string. In another page of my web app following code is working fine. but its not working for my current page i am working with. Following is the code:
$.ajax({
type: 'POST',
url: 'http://mywebapp.com/sendnames',
data: {},
success: function(result) {
alert('result: '+result);
var obj = jQuery.parseJSON(result);
alert('obj: '+obj);
// doing rest of stuff
}
});
first alert comes and shows right result. result is:
[
"Richard",
"Eric",
"John"
]
but second alert does not come.
i checked it, its a valid json. why can not i parse this json with jQuery.parseJSON(). Thanks in advance.
Try to add return type: dataType : json
$.ajax({
type: 'POST',
url: 'http://mywebapp.com/sendnames',
data: {},
dataType:'json',
success: function(result) {
console.log('result: '+result);
// doing rest of stuff
}
});
"json":
Evaluates the response as JSON and returns a JavaScript object. In jQuery 1.4 the JSON data is parsed in a strict manner; any malformed JSON is rejected and a parse error is thrown. (See json.org for more information on proper JSON formatting.)
"jsonp": Loads in a JSON block using JSONP. Adds an extra "?callback=?" to the end of your URL to specify the callback. Disables caching by appending a query string parameter, "_=[TIMESTAMP]", to the URL unless the cache option is set to true.
http://api.jquery.com/jQuery.ajax/
Replace $.ajax by $.getJSON. This is guaranteed to trigger $.parseJSON internally, so result will already be the desired JS object.
$.getJSON({
type: 'POST',
url: 'http://mywebapp.com/sendnames',
data: {},
success: function(obj) {
alert('obj: '+obj);
// doing rest of stuff
}
});
Try with adding dataType:'text', it will return string as result. and your code will run as you expect.
See the accepted answer here
You're parsing an object. You parse strings, not objects;
jQuery.parseJSON only takes strings.
Because $.ajax already parsed the data, result is Javascript object not a string. parseJSON expects a string parameter.
FROM DOCS (more on .ajax() data types here):
The json type parses the fetched data file as a JavaScript object and
returns the constructed object as the result data. To do so, it uses
jQuery.parseJSON() when the browser supports it; otherwise it uses a
Function constructor
.
Related
"This" is what I retrieve from a server:
after an ajax call in jQuery:
$.ajax({
type: "POST",
url: URL + "/webservices/WS.asmx/MyFunction",
data: JSON.stringify({ "ID": ID }),
contentType: 'application/json; charset=utf-8',
success: function (json) {
},
error: function (jqxhr, text, error) {
}
});
and I want to iterate the items inside data (which is an array). Tried with:
for (i in json.data) {
var feed = json.data[i];
console.log(feed.message);
}
but it prints nothing. Where am I wrong?
If what you've shown is really what you're getting in your success method, you have an object with a property, d, which contains a JSON string. You can parse it like this:
success: function(response) {
var data = $.parseJSON(response.d).data;
// use the data, which is an array
}
From your comment below:
But why I need to use $.parseJSON? Can't just manage it with the request? dataType for example, but still not works.
You don't need dataType, it would appear the server is returning a correct MIME type and so jQuery is already handling the first level of parsing (deserialization) correctly.
Whatever is sending you the data appears to be sending it double-encoded: First it encodes the array, then creates an object and assigns the array to it as a data property, serializes that object to JSON, then puts that string on a d property of another object, and serializes that. So although jQuery is automatically handling the first parsing (deserializing) step for you, it doesn't know about the need for the second one. I suspect you can fix this at the server level; you might want to post a separate question asking how to do that.
From your further comment:
It retuns from a .NET webservice method. I download the JSON from Facebook, after a call. And I store it inside a json variable. Then I just return it as string. I think webservice serialize that already serialized json, right?
Ah, so that's what's going wrong. You have three options:
Keep doing what you're doing and do the explicit $.parseJSON call above.
Do whatever you need to do in your web method to tell it that you're going to send back raw JSON and it shouldn't encode it; in that case, jQuery will have already parsed it for you by the time you receive it in success and you can drop the parseJSON call.
Parse the string you get from Facebook, then put the resulting array in the structure that your web method returns. Then (again) jQuery will parse it for you and you can use response.d.data directly without further parsing.
As #T.J.Crowder has pointed out your problem is related to the way you serialize your data on your backend, which is not a good practice to send the json as a string, in a real json object.
you should do it like:
success: function (json) {
var jsonObject = JSON.parse(json.d);
//then iterate through it
for(var i=0;i<jsonObject.data.length;i++){
var feed = jsonObject.data[i];
console.log(feed);
}
},
The point is using for(var key in jsonObject.data), is not safe in JavaScript, because additional prototype properties would show up in your keys.
Try using
for (var i in json.d.data) {
var feed = json.d.data[i];
console.log(i+" "+feed);
}
where
i = Key &
feed = value
I assume json is an object not string and already converted to json object. Also used json.d.data not json.data
use var in for loop and print feed not feed.message:
for (var i in json.d.data) {
var feed = json.d.data[i];
console.log(feed);
}
because I can not see {feed:{message:''}} there
I have a php returning some json in response to a POST request made via an ajax function.
In my php function I format the data like this:
//json return
$return["answers"] = json_encode($result);
echo json_encode($return);
This returns the following string:
answers: "[{"aa":"Purple","0":"Purple","ab":"Blue","1":"Blue","ac":"Red","2":"Red","ad":"Yellow","3":"Yellow"}]"
And this is where I am trying to catch it to use the data:
$.ajax({
type: "POST",
url: "http://ldsmatch.com/pieces/functions/question.functions.php",
dataType : 'JSON',
data: dataString,
success: function(data) {
alert(data.answers[0]["aa"]);
}
});
I've been trying to just alert the data so I can visualize it before setting up the vars I need, but am having some trouble formatting it correctly so it is usable.
If I alert data.answers[0] then it just shows me the first character in the string, which is a bracket [ and if i subsequently change the number it will go through each character in the returned string.
I have tried other variations, such as:
data.answers[0]["aa"] (this returns 'undefined' in the alert)
data.answers["aa"] (this returns 'undefined' in the alert)
data.answers[0] (this returns the first character of the string)
I feel like I'm close, but missing something. Any guidance appreciated.
edit:
thanks for all the suggestions. I removed the second json_encode and was able to parse with data.answers[0].aa
success: function(data) {
var json = $.parseJSON(data);
alert(json.answers[0]["aa"]);
}
Use parseJson like this
var json = $.parseJSON(data);
$(json).each(function(i,val){
$.each(val,function(k,v){
console.log(k+" : "+ v);
});
});
What if you remove double-encoding on PHP side? You've got an object with JSON string instead of object with first property being object itself, or you may explicitly decode "answers" property on client side as it was suggested above.
Trying to pass a array using ajax call.
info = [];
info[0] = 'hi';
info[1] = 'hello';
$.ajax({
type: "POST",
data: {info: info, "action": "getPatientRecords"},
url: "/mobiledoc/jsp/ccmr/webPortal/carePlanning/servicePatientmilestoneModal.jsp",
success: function(msg) {
$('.answer').html(msg);
}
});
However when i try to catch it on the server side using :
request.getParameter("info"); //Displays null**
Also, if i wish to send an array of arrays ? is it possible?
I tried using serialize however my IE throws error that serialize : object doesnt support this property i Did include jquery lib.
You can use JSON.stringify(info) to create a JSON representation of the object/array (including an array of arrays). On the server side you should be able to get the string via getParameter and then unserialize it from JSON to create constructs JSP can use.
Yes,It is Possible to send arrays.
var info_to_send = ['hi','hello'];
$.ajax({
type: "POST",
data: {info: info_to_send, "action": "getPatientRecords"},
url: "/mobiledoc/jsp/ccmr/webPortal/carePlanning/servicePatientmilestoneModal.jsp",
success: function(msg) {
$('.answer').html(msg);
}
});
You can only provide strings in a request url.
You could encode the array like so:
info = JSON.stringify(info);
// results in "['hi', 'hello']"
Then send it to the server, also JSON parse on the server.
You will need to go to http://www.json.org/ to get a Java implementation of JSON parsing.
I am receiving following data from server
"[{\"role_id\":\"1\",\"name\":\"administrator\",\"created_by_user_id\":\"2\",\"time_created_on\":null,\"is_user_based\":\"0\"},{\"role_id\":\"2\",\"name\":\"manager\",\"created_by_user_id\":null,\"time_created_on\":null,\"is_user_based\":\"0\"}]"
which is simply an array of two objects . Even after setting 'dataType' to json I am not receiving native javascript array inside my success callback function but if I use
$.ajaxSetup({
url:'/public/admin/role/list',
dataType:'json'
});
$.ajax({
success:function(data) {
alert(data[0].name); // alert box pop up as 'undefined '
var data = $.parseJSON(data);
alert(data[0].name) ; //works
}
});
Don't escape the ". They're required for JSON parsing.
[{"role_id":"1","name":"administrator","created_by_user_id":"2","time_created_on":null,"is_user_based":"0"},{"role_id":"2","name":"manager","created_by_user_id":null,"time_created_on":null,"is_user_based":"0"}]
You have a trailing comma when setting dataType in your ajaxSetup method:
dataType:'json',
^
Also I hope those \ in the JSON you have shown here are not part of the actual response from the server. The response should look like this:
[{"role_id":"1","name":"administrator","created_by_user_id":"2","time_created_on":null,"is_user_based":"0"},{"role_id":"2","name":"manager","created_by_user_id":null,"time_created_on":null,"is_user_based":"0"}]
Hi iv got this error on my ajax function using json on retrieving data. It wont return any data. Here's my code below
$.ajax({
url: "php/getCategory.php?action=getyear",
cache: false,
dataType: "json",
success: function(data){
$.each(data.items, function(i,item){
$("#catYear").append('<option value="'+item.id+'">'+item.name+'</option>');
});
}
});
When i try to remove dataType: "json" it will pass into success: function. I think the problem is on my json. I also echo the output of my getCategory.php and i think their is no problem on it. Below is the output of my php json_encode.
{items:[{"id":"1","name":"2010"},{"id":"2","name":"2011"}]}
Thanks!
from jquery documentation :
Important: As of jQuery 1.4, if the JSON file contains a syntax error, the request will usually fail silently. Avoid frequent hand-editing of JSON data for this reason. JSON is a data-interchange format with syntax rules that are stricter than those of JavaScript's object literal notation. For example, all strings represented in JSON, whether they are properties or values, must be enclosed in double-quotes. For details on the JSON format, see http://json.org/.
so jour json string has element items which is not double quoted try something like that :
{"items":[{"id":"1","name":"2010"},{"id":"2","name":"2011"}]}