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How do I save external JSON data to a JavaScript variable? [duplicate]

I have this JSON file I generate in the server I want to make accessible on the client as the page is viewable. Basically what I want to achieve is:
I have the following tag declared in my html document:
<script id="test" type="application/json" src="http://myresources/stuf.json">
The file referred in its source has JSON data. As I've seen, data has been downloaded, just like it happens with the scripts.
Now, how do I access it in Javascript? I've tried accessing the script tag, with and without jQuery, using a multitude of methods to try to get my JSON data, but somehow this doesn't work. Getting its innerHTML would have worked had the json data been written inline in the script. Which it wasn't and isn't what I'm trying to achieve.
Remote JSON Request after page loads is also not an option, in case you want to suggest that.

You can't load JSON like that, sorry.
I know you're thinking "why I can't I just use src here? I've seen stuff like this...":
<script id="myJson" type="application/json">
{
name: 'Foo'
}
</script>
<script type="text/javascript">
$(function() {
var x = JSON.parse($('#myJson').html());
alert(x.name); //Foo
});
</script>
... well to put it simply, that was just the script tag being "abused" as a data holder. You can do that with all sorts of data. For example, a lot of templating engines leverage script tags to hold templates.
You have a short list of options to load your JSON from a remote file:
Use $.get('your.json') or some other such AJAX method.
Write a file that sets a global variable to your json. (seems hokey).
Pull it into an invisible iframe, then scrape the contents of that after it's loaded (I call this "1997 mode")
Consult a voodoo priest.
Final point:
Remote JSON Request after page loads is also not an option, in case you want to suggest that.
... that doesn't make sense. The difference between an AJAX request and a request sent by the browser while processing your <script src=""> is essentially nothing. They'll both be doing a GET on the resource. HTTP doesn't care if it's done because of a script tag or an AJAX call, and neither will your server.

Another solution would be to make use of a server-side scripting language and to simply include json-data inline. Here's an example that uses PHP:
<script id="data" type="application/json"><?php include('stuff.json'); ?></script>
<script>
var jsonData = JSON.parse(document.getElementById('data').textContent)
</script>
The above example uses an extra script tag with type application/json. An even simpler solution is to include the JSON directly into the JavaScript:
<script>var jsonData = <?php include('stuff.json');?>;</script>
The advantage of the solution with the extra tag is that JavaScript code and JSON data are kept separated from each other.

It would appear this is not possible, or at least not supported.
From the HTML5 specification:
When used to include data blocks (as opposed to scripts), the data must be embedded inline, the format of the data must be given using the type attribute, the src attribute must not be specified, and the contents of the script element must conform to the requirements defined for the format used.

While it's not currently possible with the script tag, it is possible with an iframe if it's from the same domain.
<iframe
id="mySpecialId"
src="/my/link/to/some.json"
onload="(()=>{if(!window.jsonData){window.jsonData={}}try{window.jsonData[this.id]=JSON.parse(this.contentWindow.document.body.textContent.trim())}catch(e){console.warn(e)}this.remove();})();"
onerror="((err)=>console.warn(err))();"
style="display: none;"
></iframe>
To use the above, simply replace the id and src attribute with what you need. The id (which we'll assume in this situation is equal to mySpecialId) will be used to store the data in window.jsonData["mySpecialId"].
In other words, for every iframe that has an id and uses the onload script will have that data synchronously loaded into the window.jsonData object under the id specified.
I did this for fun and to show that it's "possible' but I do not recommend that it be used.
Here is an alternative that uses a callback instead.
<script>
function someCallback(data){
/** do something with data */
console.log(data);
}
function jsonOnLoad(callback){
const raw = this.contentWindow.document.body.textContent.trim();
try {
const data = JSON.parse(raw);
/** do something with data */
callback(data);
}catch(e){
console.warn(e.message);
}
this.remove();
}
</script>
<!-- I frame with src pointing to json file on server, onload we apply "this" to have the iframe context, display none as we don't want to show the iframe -->
<iframe src="your/link/to/some.json" onload="jsonOnLoad.apply(this, someCallback)" style="display: none;"></iframe>
Tested in chrome and should work in firefox. Unsure about IE or Safari.

I agree with Ben. You cannot load/import the simple JSON file.
But if you absolutely want to do that and have flexibility to update json file, you can
my-json.js
var myJSON = {
id: "12ws",
name: "smith"
}
index.html
<head>
<script src="my-json.js"></script>
</head>
<body onload="document.getElementById('json-holder').innerHTML = JSON.stringify(myJSON);">
<div id="json-holder"></div>
</body>

place something like this in your script file json-content.js
var mainjson = { your json data}
then call it from script tag
<script src="json-content.js"></script>
then you can use it in next script
<script>
console.log(mainjson)
</script>

Check this answer: https://stackoverflow.com/a/7346598/1764509
$.getJSON("test.json", function(json) {
console.log(json); // this will show the info it in firebug console
});

If you need to load JSON from another domain:
http://en.wikipedia.org/wiki/JSONP
However be aware of potential XSSI attacks:
https://www.scip.ch/en/?labs.20160414
If it's the same domain so just use Ajax.

Another alternative to use the exact json within javascript. As it is Javascript Object Notation you can just create your object directly with the json notation. If you store this in a .js file you can use the object in your application. This was a useful option for me when I had some static json data that I wanted to cache in a file separately from the rest of my app.
//Just hard code json directly within JS
//here I create an object CLC that represents the json!
$scope.CLC = {
"ContentLayouts": [
{
"ContentLayoutID": 1,
"ContentLayoutTitle": "Right",
"ContentLayoutImageUrl": "/Wasabi/Common/gfx/layout/right.png",
"ContentLayoutIndex": 0,
"IsDefault": true
},
{
"ContentLayoutID": 2,
"ContentLayoutTitle": "Bottom",
"ContentLayoutImageUrl": "/Wasabi/Common/gfx/layout/bottom.png",
"ContentLayoutIndex": 1,
"IsDefault": false
},
{
"ContentLayoutID": 3,
"ContentLayoutTitle": "Top",
"ContentLayoutImageUrl": "/Wasabi/Common/gfx/layout/top.png",
"ContentLayoutIndex": 2,
"IsDefault": false
}
]
};

While not being supported, there is an common alternative to get json into javascript. You state that "remote json request" it is not an option but you may want to consider it since it may be the best solution there is.
If the src attribute was supported, it would be doing a remote json request, so I don't see why you would want to avoid that while actively seeking to do it in an almost same fashion.
Solution :
<script>
async function loadJson(){
const res = await fetch('content.json');
const json = await res.json();
}
loadJson();
</script>
Advantages
allows caching, make sure your hosting/server sets that up properly
on chrome, after profiling using the performance tab, I noticed that it has the smallest CPU footprint compared to : inline JS, inline JSON, external JS.

Different types of methods to read JSON

I want to load JSON when the page is loading. I found two methods but what is the difference between following two methods to read JSON.
<script type="text/javascript" src="assets/json/mainpage.json"></script>
//code for what to do with this
another method is
$.getJSON("assets/json/mainpage.json")

You did not find two different methods.
The first version is not how it works.
You can load a JavaScript object that is using object notation using a script tag, so
<script type="text/javascript" src="assets/json/mainpage.js"></script>
could contain
var myJSObject = { "key":"value" };
whereas the second method will call something that returns (static or generated) content like
{ "key":"value" }
For example
$.getJSON("assets/json/mainpage.php");
would call a server process that would do
header("content-type: application/json");
echo '{ "key":"value" }';

If the assets/json/mainpage.json returns a pure JSON, the first method is totally wrong because the tag <script> is intended to serve some sort of scripting language, and a JSON is not a scripting language. It's not impossible to see something like this method, though. If the assets/json/mainpage.json supports JSON padding, mainly knows as JSONP, the following snippet is completely valid:
<script type="text/javascript" src="assets/json/mainpage.json?callback=fn"></script>
You can keep the .json extension (or any extension you like) as long as the server returns the result as a Content-Type: javascript/text on the response header and wraps the result in the callback function. Note that the value of the callback param must be a name of a function that is globally accessible.
The second method is the same as doing an ajax call to the JSON and parsing its content. This is the one you should use, between the two. Although it's kind of useless without a callback or promise for response.
$.getJSON("assets/json/mainpage.json").done(function(res) { /* handle response */ });
Hope it helps.

Using jQuery to parse a JSONP where source uses a variable instead of a function

I am trying to parse some data from a source that is formatted like this:
var = jsonReturnData = {}
instead of this:
jsonReturnData({})
If I read the file using a script tag like this:
<script src="http://foundationphp.com/phpclinic/podata.php?startDate=20150301&endDate=20150302&raw"></script>
I have no problem reading the data, but if I try to do any sort of JSON or JSONP call from within jQuery, I either get an error or no access to the data depending on how I do it.
$.getJSON('http://foundationphp.com/phpclinic/podata.php?startDate=20150301&endDate=20150321&raw', function(data) {
console.log(jsonReturnData);
});
I need to be able to load the data dynamically when someone chooses some dates. Here's a sample of the interface working, but with no access to the JSON file. The data that you see is being read by the script method.
http://iviewsource.com/exercises/codeclinic/01/

fetch data from a url in javascript [duplicate]

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.

Problems with displaying JSON data I got from a server

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
});
});