How to write JSON to multi-level global?

[Сергей Каменев]

Hi!

Is there a ready-made M function that stores a json string as a multi-level global?

Sergey

[Rod Dorman]

In article <9a0729bf-3f91-4fe9...@googlegroups.com>,

�еÑ гей Ð аменев <suka...@gmail.com> wrote:
>Is there a ready-made M function that stores a json string as a
>multi-level global?

There's no Standard M function that would do that.

What implementation are you running on?

--
-- Rod --
rodd(at)polylogics(dot)com

[Сергей Каменев]

I use YottaDB.
Any M function that works well will suit me

[K.S. Bhaskar]

There are any number of M functions to store and retrive JSON in M global variables. Ask your favorite search engine (I used DuckDuckGo) and if you don't find links to several routines, ask again here.

Regards
– Bhaskar

[Jens]

K.S. Bhaskar schrieb am Dienstag, 2. November 2021 um 03:26:09 UTC+1:
> On Monday, November 1, 2021 at 3:25:37 PM UTC-4, suka...@gmail.com wrote:
> > I use YottaDB.
> > Any M function that works well will suit me

The function at

https://github.com/lparenteau/DataBallet/blob/master/r/json.m

worked good for me...

Jens

[Сергей Каменев]

Thank you, Jens!

The code is pretty clear.

I found a thread with a few more options, but they are less clear.

https://groups.google.com/g/comp.lang.mumps/c/2-Figm7Uqbw

Sergey

[rtweed]

See the mgweb_server repository at https://github.com/robtweed/mgweb-server

You can use the routines in this repo standalone. Specifically see:

https://github.com/robtweed/mgweb-server/blob/master/DEV-PATTERN.md#json-handling-made-easy

These routines for mapping arrays to/from JSON are tried and tested...and free/open source.

[rtweed]

BTW the fact that there is a one-to-one correspondence between JSON (and XML) and M Globals is the heart of this set of documents:

https://github.com/robtweed/global_storage

and is the basis of the Node.js abstraction of Global Storage into persistent JSON/JavaScript Objects known as QEWD-JSdb:

https://github.com/robtweed/qewd-jsdb

[Sam Habiel]

You can try this too: https://github.com/shabiel/M-Web-Server/blob/master/doc/important-utilities.md#json

[Valeriu Gontia]

четверг, 4 ноября 2021 г. в 21:19:56 UTC+2, Sam Habiel:

Hello Sam !
Why, if numbers appear in a node, I get a different result ???

In the same example:
S X ("myObj", "booleanT") = "true"
S X ("myObj", "booleanF") = "false"
S X ("myObj", "numeric") = 3.1416
S X ("myObj", "nullValue") = "null"
S X ("myObj", "array", 1) = "one"
S X ("myObj", "array", 2) = "two"
S X ("myObj", "array", 3) = "three"
S X ("myObj", "subObject", "fieldA") = "hello"
S X ("myObj", "subObject", "fieldB") = "world"
JSON (1) = "{" myObj ": {" array ": [" one "," two "," three "]," booleanF ": false," booleanT ": true," nullValue ": null," numeric ":"
JSON (2) = "3.1416," subObject ": {" fieldA ":" hello "," fieldB ":" world "}}}"

In my case:
XX (501, "array", 1) = "one"
XX (501, "array", 2) = "two"
XX (501, "array", 3) = "three"
XX (501, "booleanF") = "false"
XX (501, "booleanT") = "true"
XX (501, "nullValue") = "null"
XX (501, "numeric") = 3.1416
XX (501, "subObject", "fieldA") = "hello"
XX (501, "subObject", "fieldB") = "world"
JSON (1) = "{[{" array ": [" one "," two "," three "]," booleanF ": false," booleanT ": true," nullValue ": null," numeric ": 3.1416 , "
JSON (2) = "" subObject ": {" fieldA ":" hello "," fieldB ":" world "}}]}"

It happens to me that the nodes of globals contain only numbers
(codes) ...

[Sam Habiel]

The encoder behaves differently if you start with a number (it assumes you want an array) vs not (it will assume that you want an object).

--Sam

[Valeriu Gontia]

четверг, 11 ноября 2021 г. в 16:49:31 UTC+2, Sam Habiel:

I'm testing a Rob Tweed encoder
Get a different result:
s aa = $$ arrayToJSON ^% zewdJSON ("XX")
aa="{"501":{"array":["one","two","three"],"booleanF":false,"booleanT":true,"nullValue":"null","numeric":3.1416,"subObject":{"fieldA":"hello","fieldB":"world"}}}"

[Valeriu Gontia]

четверг, 11 ноября 2021 г. в 20:17:39 UTC+2, Valeriu Gontia:

I get the same results Rob Tweed and Winfried Bantel encoder:
XX(501,8924)="true"
XX(501,8925)="false"
XX(501,8926)=3.1416
XX(501,8927)="null"
XX(501,8928,1)="one"
XX(501,8928,2)="two"
XX(501,8928,3)="three"
XX(501,8929,222)="hello"
XX(501,8929,333)="world"
aa="{"501":{"8924":true,"8925":false,"8926":3.1416,"8927":"null","8928":["one","two","three"],"8929":{"222":"hello","333":"world"}}}"
bb="{"501":{"8924":"true","8925":"false","8926":3.1416,"8927":"null","8928":{"1":"one","2":"two","3":"three"},"8929":{"222":"hello","333":"world"}}}"

Sam, i like your approach of splitting the JSON into a one-dimensional array. Ultimately, I can pass a large amount of data to the client in a loop. But this doesn't fit the structure of my globals.
As I showed above, this suits me for my globals. But, here the function returns a string that does not exceed 32 KB, that is, i am limited in transferring data to the client.

[rtweed]

What were you expecting the JSON representation of your Global contents to be? My encoder is producing exactly what I'd have expected

Rob

[Valeriu Gontia]

пятница, 12 ноября 2021 г. в 15:14:40 UTC+2, rtweed:

> What were you expecting the JSON representation of your Global contents to be? My encoder is producing exactly what I'd have expected
>
> Rob

There are cases in old M implementations when it is necessary to return more than 32 kb to the JSON client
Your decoder is fine, but it returns the maximum line error.
CADRE> d arrayToJSON^%zmgwebUtils ("^CAD")

... ... ... s json = json_value_ ","
^
<MAXSTRING> walkArray + 51 ^% zmgwebUtils

CADRE 15d5>

Sam has everything OK, but the structure is not like yours.
CADRE> d encode ^%zwebjsonEncode ("^CAD","JSON")

CADRE>

[rtweed]

You can always reconfigure your M system to increase the maximum size allowed for data. Of course there's also the maximum combined global subscript length issue that can limit JSON to/from global mapping. A good alternative is to use the DOM APIs to map JSON. These are implemented in my EWD source code (see my EWD repo on Github) and in QEWD (implemented as JavaScript APIs). See:

https://github.com/robtweed/global_storage/blob/master/XML_DB.md
https://github.com/robtweed/qewd-jsdb/blob/master/DOM.md (the last sections deal with JSON mapping using the DOM)

Rob