I'm new to JSON/AJAX and
I've some problems with displaying data out of a JSON-object I've got from a server..
The url "http://localhost:8387/rest/resourcestatus.json" represents this object, which I would like to display via HTML/Javascript.. This object stores some monitoring information:
{"groupStatus":[
{"id":"AL Process","time":1332755316976,"level":0,"warningIds":[],"errorIds":[]},
{"id":"AL:instance1","time":1332919465317,"level":0,"warningIds":[],"errorIds":[]},
{"id":"AL:instance2","time":1332919465317,"level":1,"warningIds":["documentarea.locked"],"errorIds":[]},
{"id":"SL","time":1331208543687,"level":0,"warningIds":[],"errorIds":[]}
]}
Since the requested url is different from my domain I can't create a typical XMLHttpRequest.. So I found out that there's an AJAX cross-domain request which can be realised via jQuerys "getJSON()" method.
I want to display the ids and their level in a table.
Any solution to achieve this?
i think you are referring to JSONP. see jQuery.ajax Ex:
var url = 'http://localhost:8387/rest/resourcestatus.json';
$.getJSON(url+'?callback=?', function(data)
{
//data is
/*{
"groupStatus":
[
{"id":"AL Process","time":1332755316976,"level":0,"warningIds":[],"errorIds":[]},
{"id":"AL:instance1","time":1332919465317,"level":0,"warningIds":[],"errorIds":[]},
{"id":"AL:instance2","time":1332919465317,"level":1,"warningIds":["documentarea.locked"],"errorIds":[]},
{"id":"SL","time":1331208543687,"level":0,"warningIds":[],"errorIds":[]}
]
}*/
});
on the server side you will need to wrap the response into a JavaScript function: response = Request["callback"] +"("+ response+")";
the result will look like this:
?({"groupStatus":[{"id":"AL ....})
So the browser will actually load a valid java script code.
The callback function of $.getJSON contains the result of the AJAX call in it's argument.
$.getJSON('http://localhost:8387/rest/resourcestatus.json', function(data) {
$(data.groupStatus).each(function() {
// do something with $(this).id
});
});
Related
I'm trying to load a JSON file by link and then align data (like title, date etc) to variables so I can use them. Right now, I don't care about variables. I just want to alert() them but something seems like I'm doing it wrong, alert returns nothing!
I use JSfidle to run the code. The code is this:
var JSON_unparsed = $.getJSON('http://www.14deftera.gr/feeds/posts/default?orderby=published&alt=json') ;
var JSON = JSON.parse(JSON_unparsed) ;
alert(JSON.feed.entry[0].title.$t) ;
The URL I want to parse is: http://www.14deftera.gr/feeds/posts/default?orderby=published&alt=json
and here you can see the JSON how is structured if that can help you:
You can use JSONP for this:
Update, for better understanding how to work with returned JSON.
var id, title;
$.ajax({
url: 'http://www.14deftera.gr/feeds/posts/default?orderby=published&alt=json',
jsonp: "callback",
dataType: "jsonp"
}).done(function(r){
// r is returned JSON
for(var i in r)
// for ex ID is this
id = r[i].id.$t;
// and title
title = r[i].title.$t;
// and so on, check the json, I mean check the browser console by hitting F12, below code will print the whole JSON
console.log(r[i]);
});
Codepen link: http://codepen.io/m-dehghani/pen/grXrrp?editors=0010
In addition to adeneo's reply, in your code, JSON_unparsed variable is holding something called (differed or promise object), this object might be holding the data inside it,but you are using the wrong way to pull it out. in order for you to get it out, you need to call (.done()) function, see the below:
var JSON_unparsed = $.getJSON('http://www.14deftera.gr/feeds/posts/default?orderby=published&alt=json').done(function(json){
console.log(json);
console.log(json.feed.entry[0].title.$t);
});
aside from that, if you got an error with something like this:
XMLHttpRequest cannot load http://www.14deftera.gr/feeds/posts/default?orderby=published&alt=json&_=1459788714707. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://stackoverflow.com' is therefore not allowed access.
it means that you are not allowed to call this API/URL from your current domain.
One more thing, if you are using getJSON method, there is no need to parse the returned data, jquery will parse it for you
How do I extract the data below. I only want to print out the value number after "networkdiff" in this API.
This is the URL for the API from a different website:
http://21.luckyminers.com/index.php?page=api&action=getpoolstatus&api_key=8dba7050f9fea1e6a554bbcf4c3de5096795b253b45525c53562b72938771c41
I want the code to automatically retrieve the data from the URL above, and display the value after "networkdiff" to display on my other webpage.
Here's my code so far that I will put in my own webpage:
<HTML>
<body>
<script>
I don't know what I should put in this script part.
</script>
</body>
</html>
Below is the data the URL showed up as:
{
"getpoolstatus":{
"version":"1.0.0",
"runtime":10.684967041016,
"data":{
"pool_name":"21 Coin Pool # Luckyminers.com",
"hashrate":0,
"efficiency":97.79,
"workers":0,
"currentnetworkblock":0,
"nextnetworkblock":1,
"lastblock":40544,
"networkdiff":1,
"esttime":0,
"estshares":4096,
"timesincelast":1240429,
"nethashrate":0
}
}
}
Since the data is coming from an external domain, you can't use Ajax to get the data, unless the server enabled CORS. This doesn't seem to be the case, but it seems to support JSONP:
<script>
function processResponse(data) {
console.log(data);
}
</script>
<script src="http://21.luckyminers.com/index.php?page=api&...&callback=processResponse></script>
The callback=parseResponse makes the server return JS consisting of a function call to processResponse. How to access the information you actually want is explained in Access / process (nested) objects, arrays or JSON.
You need to include JSON.js in your web page to use JSON function in javascript. Here is the URL for download
https://github.com/douglascrockford/JSON-js
And then you can use beloe code to parse the JOSN string into javascript object.
var objectJSON = JSON.parse(jsonStr);
You can alse used stringify fucntion to the viceversa.
In which way you call the JSON?
You can call it with a callback function (working example), including it as a script:
updateResult=function()
{
var s=document.createElement('script');
s.src=domain+"/index.php?page=api&callback=showResult&action=getpoolstatus&api_key="+api_key;
document.body.appendChild(s);
}
You must have the callback defined like:
showResult=function(data)
{
document.getElementById('result').innerText=data.getpoolstatus.data.networkdiff;
}
If you call it with JQuery and get the JSON object, you can define the callback in the argument like the following example, but you must have same-origin (your script must run with the same domain (21.luckyminers.com in this case):
$.getJSON(
domain+"/index.php?page=api&action=getpoolstatus&api_key="+api_key,
function(data)
{
document.getElementById('result').innerText=data.getpoolstatus.data.networkdiff;
}
);
But in any case, be careful. Where did you get the API key? If you put it on a client-side script (like JavaScript) anybody can read the key, and with that key maybe do some damage… :S
This question already has answers here:
Ways to circumvent the same-origin policy
(8 answers)
Closed 9 years ago.
I am trying to fetch a data file from a URL given by the user, but I don't know how to do. Actually, I can get data from my server successfully. Here is my code:
$("button#btn-demo").click(function() {
$.get('/file', {
'filename' : 'vase.rti',
},
function(json) {
var data = window.atob(json);
// load HSH raw file
floatPixels = loadHSH(data);
render();
});
});
It can fetch the binary data from my server, parse the file and render it into an image. But now I want it work without any server, which means users can give a URL and javascript can get the file and render it. I know it's about the cross-site request. Can you tell me about it and how to realize it?
Thanks in advance!
assuming your URL is the address of a valid XML document this example will go grab it. if the URL is on a different domain than the one that's holding your scripts you will need to use a server side scripting language to got out and grab the resource (XML doc at URL value) and return it your domain. in PHP it would be ...
<?php echo file_get_contents( $_GET['u'] );
where $_GET['u'] is a URL value from your USER. let's call our PHP script proxy.php. now our JavaScript will call our proxy.php and concatenate the URL value to the end which will allow us to pass the URL value to the PHP script.
addy = $("#idOfInputFieldhere").val();
$.ajax({
url: 'proxy.php?u='+addy, /* we pass the user input url value here */
dataType:'xml',
async:false,
success:function(data){
console.log(data); /* returns the data in the XML to the browser console */
}
});
you'll need to use the js debugger console in chrome to view data. at this point you'd want to pull out data in a loop and use find() http://api.jquery.com/?s=find%28%29
I'm not very familiar with jQuery, but as I know, due to the same origin policy, the browser won't let any JavaScript code to make an AJAX request to a domain other than its own. So in order to retrieve some data (specially JSON formatted), you can add a <script> element to your page dynamically and set its src property to the address of the data provider. Something like this:
<script src='otherdomain.com/give_me_data.json'/>
This only works if you need to access some static data (like the url above) or you have access to the server side code. Because in this scenario, the server side code should return an string like:
callbackFunction({data1: 'value1', data2: 'value2', ...});
As the browser fetches the item specified in src property, tries to run it (because it know it's a script). So if the server sends a function call as a response, the function would be called immediately after all data has been fetched.
You can implement the server side in such a way that it accepts the name of the callback function as a parameter, loads requested data and generates an appropriate output that consists of a function call with loaded data as a json parameter.
Here's some simple Javascript:
(function($){
var ajax_callback = function(data) { window.location.hash = data.h1; };
$('.clickable').live('click', function() {
$.post('server.fcgi', {}, ajax_callback, 'json');
}
);
})(jQuery);
The server is a c++ binary (yes, i know) that spits out (through fast_cgi) the string:
{"h1":"newhash"}.
The expected behavior is that the URL should change.
Instead, nothing happens and Firebug complains that 'data' is "null"!.
Any help would be greatly appreciated!
Will.
When the following code enters "ajax_callback", it says that "data" is "null"!.
But the server is a c++ binary that is confirmed to return the JSON string {"h1":"newhash"}.
Anyone have an idea why JQuery seems unable to accept the JSON data when calling the ajax_callback?
I did have similar problem as you have mentioned when using $.POST().
There are two things if you are using jquery $.post method. You need to add an extra bracket before defined data type ("JSON") as shown below. I don't know why but it works, it will return data.
$.post('server.fcgi', {}, ajax_callback,{}, 'json');
The second thing is that you will need to parse JSON data using $.parseJSON(data) in side the callback function.
One more thing to make sure that the url to fetch JSON, the page document type should be defined as JSON in the header.
I have given an example below.
$.post("url/path/here/to/json", {}, function(data){
if(data){ // just in case the called program had a problem
var obj = $.parseJSON(data);
.... do everything else using the Obj->
}
},{},"json");
This will work.
However I recommend to you to use another Jquery function specially implemented for JSON, that is called
$.getJSON();
Here is the url for more information
And I am suggesting you to use the following method instead of the one described by you.
$(document).ready(function(){
$('.clickable').live('click', function() {
$.getJSON('server.fcgi', function(data){
window.location.hash = data.h1;
});
}
);
});
Make sure the server also returns the correct HTTP headers before the payload. E.g.:
HTTP/1.0 200 OK
Content-Type: application/json
Content-Length: ...
...
{"h1":"bla"}
From your description, I could not quite make out if all it did was printf("{\"h1\":\"bla\"}"); or not.
To check the actual result, use a command line tool like HEAD, GET, wget, curl, or even nc. If you are not able to use one of those, you might get some clues from the Net panel in Firebug and the like.
Probably not the answer you want to hear, but I assume you're using jQuery 1.4.2? I noticed that this does work as expected in 1.3.2 so you might want to consider using that instead. :(
I have an ExtJS based application. When editing an object, an ExtJS window appears with a number of tabs. Three of these tabs have Ext GridPanels, each showing a different type of data. Currently each GridPanel has it's own JsonStore, meaning four total AJAX requests to the server -- one for the javascript to create the window, and one for each of the JsonStores. Is there any way all three JsonStores could read from one AJAX call? I can easily combine all the JSON data, each one currently has a different root property.
Edit: This is Ext 2.2, not Ext 3.
The javascript object created from the JSON response is available in yourStore.reader.jsonData when the store's load event is fired. For example:
yourStore.on('load', function(firstStore) {
var data = firstStore.reader.jsonData;
otherStore.loadData(data);
thirdStore.loadData(data);
}
EDIT:
To clarify, each store would need a separate root property (which you are already doing) so they'd each get the data intended.
{
"firstRoot": [...],
"secondRoot": [...],
"thirdRoot": [...]
}
You could get the JSON directly with an AjaxRequest, and then pass it to the loadData() method of each JSONStore.
You may be able to do this using Ext.Direct, where you can make multiple requests during a single connection.
Maybe HTTP caching can help you out. Combine your json data, make sure your JsonStores are using GET, and watch Firebug to be sure the 2nd and 3rd requests are not going to the server. You may need to set a far-future expires header in that json response, which may be no good if you expect that data to change often.
Another fantastic way is to use Ext.Data.Connection() as shown below :
var conn = new Ext.data.Connection();
conn.request({
url: '/myserver/allInOneAjaxCall',
method: 'POST',
params: {
// if you wish too
},
success: function(responseObj) {
var json = Ext.decode(responseObj.responseText);
yourStore1.loadData(json.dataForStore1);
yourStore2.loadData(json.dataForStore2);
},
failure: function(responseObj) {
var message = Ext.decode(responseObj.responseText).message;
alert(message);
}
});
It worked for me.