How to properly build and append a json file from variables - json

Question

I'm practising programming an application that takes user input and then outputs it to a json file.
I found a how to that explains how to do it. For the sake of length, I'm leaving out the input code and just including the json builder.
ASSIGN
uComp = "testCompany"
uEmail = "testEmail"
uName = "testName"
uAdd = "Additional"
.
DEFINE VARIABLE myObj AS JsonObject NO-UNDO.
DEFINE VARIABLE myData AS JsonObject NO-UNDO.
DEFINE VARIABLE dataParams AS JsonObject NO-UNDO.
DEFINE VARIABLE lResult AS LONGCHAR NO-UNDO
VIEW-AS EDITOR LARGE SIZE 60 BY 16.
DEFINE VARIABLE lJArray AS JsonArray NO-UNDO.
DEFINE VARIABLE lAnotherArray AS JsonArray NO-UNDO.
OUTPUT TO "output path.json".
myObj = NEW JsonObject().
dataParams = NEW JsonObject().
myObj:Add("id", "01").
dataParams:Add("Company_name", uComp).
dataParams:Add("uEmail", uEmail).
dataParams:add("uName", uName).
dataParams:add("AddInfo", uAdd).
lJArray = NEW JsonArray().
lJArray:Add(dataParams).
myObj:Add("data", lJArray).
myObj:Write(lResult, TRUE).
DISPLAY lResult.
That part works fine, but my output is like so:
lResult-----------------------------------------------------
{
"id": "01",
"data": [
{
"Company_name": "testCompany",
"uEmail": "testEmail",
"uName": "testName",
"AddInfo": "Additional"
}
]
}
how do I prevent the
lResult-----------
from being added to the file.
Secondly, I want to add additional information to the file when the code runs again so that the output will become.
{
"id": "01",
"data": [
{
"Company_name": "testCompany",
"uEmail": "testEmail",
"uName": "testName",
"AddInfo": "Additional"
},
{
"Company_name": "testCompany",
"uEmail": "testEmail",
"uName": "testName",
"AddInfo": "Additional"
}
]
}
What is the correct way to target a point in the file and add additional objects?
I though it might be something along the lines of an
append
property.

Answer 1

I would leave the complete JSON I/O to the JSON parser in the language. So instead of the append, I'd read in the file into a JSON object and add the additional objects/properties in memory and write back to a file.
Just an output with append won't produce value JSON. This should work:
FILE-INFORMATION:FILE-NAME = "myfile.json" .
IF FILE-INFORMATION:FULL-PATHNAME > "":U THEN DO:
myObj = CAST ((NEW ObjectModelParser()):ParseFile(FILE-INFORMATION:FULL-PATHNAME),
JsonObject) .
lJArray = myObj:GetJsonArray("data") .
END.
ELSE DO:
myObj = NEW JsonObject().
myObj:Add("id", "01").
lJArray = NEW JsonArray().
myObj:Add("data", lJArray).
END.
dataParams = NEW JsonObject().
dataParams:Add("Company_name", uComp).
dataParams:Add("uEmail", uEmail).
dataParams:add("uName", uName).
dataParams:add("AddInfo", uAdd).
lJArray:Add(dataParams).
myObj:WriteFile("myfile.json", TRUE).

Answer 2

how do I prevent the
lResult-----------
from being added to the file.
I suspect it's because the variable has a VIEW-AS phrase on the definition. But using the JsonObject as an object and calling the WriteFile method is the (far) better approach.