mORMot Open Source

tfopc

Member

Registered: 2024-01-08

Posts: 50

FlattenFromNestedObjects only nesting one(root) level

Hi ab,

i played around with the new yaml parser (thanks, zen010101 and ab for the addition)

i try to do some helper to migrate yaml/json -> ini-files and back.

For saving json/yaml in the ini need to flatten the nested objects...

So i catched this ...

Doc.InitJson('{"a":{"b":1,"c":1},d:3}');
Doc.FlattenFromNestedObjects('.');
CheckEqual(Doc.ToJson, '{"a.b":1,"a.c":1,"d":3}');

I assume that “FlattenFromNestedObjects” completely flattens the nested structures.

So that this test would succeed.

Doc.InitJson('{"a":{"b":{"bb":2},"c":1},d:3}');
Doc.FlattenFromNestedObjects('.');
CheckEqual(Doc.ToJson, '{"a.b.bb":2,"a.c":1,"d":3}');

But at the moment it only nesting the root - level:

{"a":{"b":{"bb":2},"c":1},d:3} -> {"a.b":{"bb":2},"a.c":1,"d":3}

So this test also fails.

Doc.InitJson('{"a":{"b":{"bb":2},"c":1},d:3}');
Doc.FlattenFromNestedObjects('.');
CheckNotEqual(Doc.ToJson, '{"a.b":{"bb":2},"a.c":1,"d":3}');

Is this expected?

Thank you.

Tobias

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 15,475

Website

Re: FlattenFromNestedObjects only nesting one(root) level

Yes, it only flatten the root level.
It was on purpose, because it was designed and used in a specific case  of a generic single level key/value property dictionary context.

For INI, you don't need to 'flatten' the nested objects.
You could use dedicated sections per object.
This is what mORMot IniToObject() does - and TSynJsonFileSettings.

tfopc

Member

Registered: 2024-01-08

Posts: 50

Re: FlattenFromNestedObjects only nesting one(root) level

Hi, ab

a simple "FlattenFromNestedObjects" defined like this, will do the job

function TDocVariantData.FlattenFullFromNestedObjects(aSepChar: AnsiChar = '.';
      aNestedArrayStartIndex: PtrInt = -1): boolean;
begin
   result := FlattenFromNestedObjects(aSepChar,aNestedArrayStartIndex);
   if result then
      while FlattenFromNestedObjects(aSepChar,aNestedArrayStartIndex) do;
end;

Use case is for example to save a nested json as csv.

Maybe it can also be integrated in FlattenFromNestedObjects via an additional optional param (flattenfull:boolean=false)

Feel free to integrate it.
Of course a simple "while doc.FlattenFromNestedObjects do;" also do the job in application code.

ab

Administrator

From: France

Registered: 2010-06-21

Posts: 15,475

Website

Re: FlattenFromNestedObjects only nesting one(root) level

Documented as such:
https://github.com/synopse/mORMot2/commit/13cd97f66