# Issue with loadJSON

**URL:** <https://discourse.processing.org/t/issue-with-loadjson/7682>\
**Category:** Coding Questions\
**Created:** [January 20, 2019, 5:27pm UTC](https://discourse.processing.org/t/issue-with-loadjson/7682 "2019-01-20T17:27:15Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![aliser](https://avatars.discourse-cdn.com/v4/letter/a/eb9ed0/32.png) [@aliser](https://discourse.processing.org/u/aliser)\
**Post date:** [January 20, 2019, 5:27pm UTC](https://discourse.processing.org/t/issue-with-loadjson/7682/1 "2019-01-20T17:27:15Z")

</div>

How to use it for example with wikipedia api? On the request

`loadJSON("https://en.wikipedia.org/w/api.php?action=opensearch&search=unicorn, gotData, 'jsonp')`

I get a response in the form

`Uncaught (in promise) TypeError: Cannot read property 'get' of undefined at VM70 p5.min.js:10`

---

<div class="post-metadata">

**Author:** ![kll](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/kll/32/964_2.png) [@kll](https://discourse.processing.org/u/kll)\
**Post date:** [January 21, 2019, 2:35am UTC](https://discourse.processing.org/t/issue-with-loadjson/7682/2 "2019-01-21T02:35:51Z")

</div>

hi @aliser,

-a- would be better to have the full code  
or the link to the  
[https://editor.p5js.org/kll/sketches/Ywk8WgbK7](https://editor.p5js.org/kll/sketches/Ywk8WgbK7)

-b- so what is known is that there is a current problem about  
CORS  
means when you call to / from a https site  
you see possibly no response,  
but in ( context menue // right mouse click ) Inspect tab CONSOLE see

```auto
Failed to load 
https://en.wikipedia.org/w/api.php?action=query&list=search&srsearch=p5js&utf8=&format=json: 
No 'Access-Control-Allow-Origin' header is present on the requested resource. 
Origin 'https://editor.p5js.org' is therefore not allowed access. 
If an opaque response serves your needs, 
set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

```

you can play in above linked sketch  
using url1 ( works ) or url2 ( wiki give error )  
while a call in browser

```auto
https://en.wikipedia.org/w/api.php?action=query&list=search&srsearch=p5js&utf8=&format=json

```

usually works here.

---

<div class="post-metadata">

**Author:** ![aliser](https://avatars.discourse-cdn.com/v4/letter/a/eb9ed0/32.png) [@aliser](https://discourse.processing.org/u/aliser)\
**Post date:** [January 21, 2019, 7:15am UTC](https://discourse.processing.org/t/issue-with-loadjson/7682/3 "2019-01-21T07:15:16Z")

</div>

So ‘Access-Control-Allow-Origin’ is a server thing and we have to ask for permission or something like that and add to request ‘origin=\*’. And there is a another option which uses xmlhttprequest.

Code:  
[https://editor.p5js.org/aliser/sketches/q\_7DhSwYt](https://editor.p5js.org/aliser/sketches/q_7DhSwYt)

---

<div class="post-metadata">

**Author:** ![GoToLoop](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/gotoloop/32/86_2.png) [@GoToLoop](https://discourse.processing.org/u/GoToLoop)\
**Post date:** [January 21, 2019, 7:21am UTC](https://discourse.processing.org/t/issue-with-loadjson/7682/4 "2019-01-21T07:21:20Z")

</div>

As @aliser has just mentioned, we need `'origin=*'` for CORS, according to Wikipedia API’s docs: 🗒  
[MediaWiki.org/wiki/API:Cross-site\_requests](http://MediaWiki.org/wiki/API:Cross-site_requests)

Here’s my own demo sketch for it: 🕶

> **[JSON Wikipedia CORS Origin](https://Bl.ocks.org/GoSubRoutine/f13a55e7cfaabea6aa6bdf028c1f2f1e)**
>
> GoSubRoutine’s Block f13a55e7cfaabea6aa6bdf028c1f2f1e

```javascript
/**
 * JSON Wikipedia CORS Origin (v1.1.2)
 * GoToLoop (2019-Jan-21)
 *
 * https://Discourse.Processing.org/t/issue-with-loadjson/7682/4
 * https://Bl.ocks.org/GoSubRoutine/f13a55e7cfaabea6aa6bdf028c1f2f1e
 */

"use strict";

const HTTP = 'https://', SITE = 'en.Wikipedia.org',
      FOLD = '/w/', FILE = 'api.php',
      ASK = '?', AND = '&',
      ORI = 'origin=*',
      ACT = 'action=opensearch',
      WORD = 'search=unicorn',
      LINK = HTTP + SITE + FOLD + FILE + ASK + ORI + AND + ACT + AND + WORD,
      LIST = 'ol', ITEM = 'li', BLANK = '_blank', COLOR = 'Red';

let jsonArray;

function preload() {
  print(LINK);
  jsonArray = loadJSON(LINK, print);
}

function setup() {
  noCanvas(), noLoop();
  console.table(jsonArray);

  const list = createElement(LIST)
          .style('color', COLOR)
          .style('font-weight: bold')
          .style('font-size: 1.2em');

  for (const url of jsonArray[3])
    createElement(ITEM).child(createA(url, url, BLANK)).parent(list);
    //createElement(ITEM, url.link(url)).parent(list);
}

```