loadJSON() changes order of JSON entries

Scriptable
1

Hello,

I just discovered Scriptable and I’m loving it, thank you!

I made a scripted based on the macstories example. When I select a dictionary inside an array it changes the order of the entries.
The following code should recreate my issue:

let url = "https://macstories.net/feed/json"
let req = new Request(url)
let json = await req.loadJSON()
console.log(json["items"][0])

In the original JSON the order is: “id”, “url”, “title”, “content_html” …
but using loadJSON() the order is: “author”, “id”, “content_html”, “title”…

For my use the order is important because I have one event per entry in chronological order.

Thanks in advance,
Régis

2

Technically the object order is not necessarily maintained, but where a parser can maintain it, it can be useful. But for transportability, you would ideally design in any sorting you require.

As an aside, here’s a good article that talks about the topic and provides good supporting arguments for the retention of ordering.

Whilst I’m all for defensive and transportable coding, it is of course a very useful feature to have if the code is only ever being run in the one place. Simplicity is always a winner.

1 Like
3

as long as the “items” order is not being changed, how does that matter? When you are looping the items. items[0].id is always going to be items[0].id no?

4

So the OP wants to loop through the key/value pairs.

I believe the design point is to use the key in a “direct access” way, rather than sequentially.

Or did I misunderstand?

5

That is what I had to realise the hard way. Thanks for the article.

The problem is that I don’t necessarily know the keys, in my case they are random dates:

[
 {
   "Category": "Store open",
   "2018-08-26": "false",
   "2018-09-07": "false",
   "2018-09-23": "false",
   "2018-10-21": "true",
   "2018-11-04": "true",
   "2018-11-18": "false",
   "2018-12-02": "true",
   "2018-12-16": "false",
   "2019-01-20": "false",
   "2019-02-03": "true",
   "2019-02-17": "false"
 },
 {
   "Category": "In charge",
   "2018-08-26": "Orcas",
   "2018-09-07": "WaWaLa.18",
   "2018-09-23": "Tiger",
   "2018-10-21": "Polarwölfe",
   "2018-11-04": "Erdmännchen",
   "2018-11-18": "Seelöwen",
   "2018-12-02": "Geckos",
   "2018-12-16": "?",
   "2019-01-20": "Eisbahn",
   "2019-02-03": "Seeadler",
   "2019-02-17": "Scouts"
 }
]

The easiest solution I can think of, is to change my json structure.

6

You can loop thru the keys in an Json object

const keys = Object.keys(someJsonObject)
for (const key of keys) {
  console.log(“key”, key);
   console.log(“value”, someJsonObject[key]);
}

In your previous example your json object is an array of objects then you will need to first loop through the array elements

for (const item of arrayObject) {
  const keys = Object.keys(item)
  for (const key of keys) {
    console.log(“key”, key);
     console.log(“value”, someJsonObject[key]);
  }
}
1 Like
7

I believe you can embed arrays in JSON. That might be order preserving.

8

Yes - it is stated in the RFC 7159 (JSON) specification that arrays are considered ordered.

image
ECED8F8D-45FF-49FB-93C9-49E49CDB6A20.jpeg1242×1908 720 KB

9

It comes down to JSON Objects in Javascript are not ordered lists like Array are. The way you get data out of a JSON object is based on a key name, not a position index like Arrays.

–Scott.

1 Like
10

It also occurred to me that the keys could be “tree-like” with the top level key being a year.

Doesn’t solve the underlying issue but might be a better organisation. Something for the OP to consider.