GlobalToJSON-XL-Academic

GlobalToJSON-XL-Academic

This package offers a utility to export an XLarge Global into a JSON object file and to show or import it again.
In a previous example, this all was processed in memory. But if this is a large Global you may either
experience <MAXSTRING> or an <STORE> error if the generated JSON structure exceeds available memory.

Academic refers to the structure created.

• each node of the Global including the top node is represented as a JSON object
• {"node":<node name>,"val":<value stored>,"sub":[<JSON array of subscript objects>]}
• value and subscript are optional but one of them always exists for a valid node
• the JSON object for the lowest level subscript has only value but no further subscript.

So this is basically a 1:1 image of your global and it's exported to a file (default: gbl.json)
In addition to the export, a show method displays the generated file.
The tricky part is the import from file. It is a customize JSON parser as all others just
operate in memory. this fails with a reasonable-sized Global
(eg. ^oddDEF with ~ 1.7 million nodes takes ~ 78MB JSON file.)

How to Test it

This is the pre-loaded Global ^dc.MultiD for testing.

There are 3 methods available

• ClassMethod export(gref As %String = "^%", file = "gbl.json") As %String
  file = 0 >>> display to terminal
• ClassMethod show(file = "gbl.json") As %String
• ClassMethod import( file = "gbl.json", test = 0) As %String
  test = 1 >>> load into a PPG

Open IRIS terminal or console session

USER>write ##class(dc.GblToJSON.XLA).export("^dc.MultiD")
File gbl.json created
USER>write ##class(dc.GblToJSON.XLA).export("^dc.MultiD",0)

{"node":"^dc.MultiD"

,"val":5

,"sub":[

{"node":1

,"val":"$lb("Braam,Ted Q.",51353)"

,"sub":[

{"node":"mJSON"

,"val":"{}"

}

---  truncated ---
USER>>write ##class(dc.GblToJSON.XLA).show()

{"node":"^dc.MultiD"

,"val":5

,"sub":[

{"node":1

,"val":"$lb("Braam,Ted Q.",51353)"

---  truncated ---

validated JSON object

Now we want to verify the load function as a test into a PPG

USER>write ##class(dc.GblToJSON.XLA).import(,1)
Global ^||dc.MultiD loaded
USER>zwrite ^||dc.MultiD

^||dc.MultiD=5

^||dc.MultiD(1)=$lb("Braam,Ted Q.",51353)

^||dc.MultiD(1,"mJSON")="{}"

^||dc.MultiD(2)=$lb("Klingman,Uma C.",62459)

^||dc.MultiD(2,2,"Multi","a")=1

^||dc.MultiD(2,2,"Multi","rob",1)="rcc"

^||dc.MultiD(2,2,"Multi","rob",2)=2222

^||dc.MultiD(2,"Multi","a")=1

^||dc.MultiD(2,"Multi","rob",1)="rcc"

^||dc.MultiD(2,"Multi","rob",2)=2222

^||dc.MultiD(2,"mJSON")="{""A"":""ahahah"",""Rob"":""VIP"",""Rob2"":1111,""Rob3"":true}"

^||dc.MultiD(3)=$lb("Goldman,Kenny H.",45831)

^||dc.MultiD(3,"mJSON")="{}"

^||dc.MultiD(4)=$lb("","")

^||dc.MultiD(4,"mJSON")="{""rcc"":122}"

^||dc.MultiD(5)=$lb("","")

^||dc.MultiD(5,"mJSON")="{}"
USER>

q.a.d.

Article in DC

Video