Flatten nested Json objects with JQ

Question

I am creating a script to transform JSON objects to "string" files (for translation purposes). the idea is to transform:

{
 "TRANSLATION1": "text1",
 "TRANSLATION2": "text2"
}

into

"TRANSLATION1" = "text1";
"TRANSLATION2" = "text2";

That was done with : jq -r 'to_entries|map("\"\(.key)\"=\(.value|tojson);")|.[]'

Nice!

Now, my problem is with nested objects:

{
 "TRANSLATION1": "text1",
 "TRANSLATION2": "text2",
 "TRANSLATION3": {
 "SUBTRANS1": "subtranslation1",
 "SUBTRANS2": "subtranslation2",
 }
}

I would like to have as result:

"TRANSLATION1" = "text1";
"TRANSLATION2" = "text2";
"TRANSLATION3.SUBTRANS1" = "subtranslation1";
"TRANSLATION3.SUBTRANS2" = "subtranslation2";

Can anyone help?! I have been scratching my head for hours now...

Answer 1

One approach would be to use tostream:

tostream
| select(length==2)
| (.[0] | join(".")) as $k
| .[1] as $v
| "\"\($k)\" = \"\($v)\";"

When used with the -r command-line option, this will produce the desired results, assuming the input is valid JSON.

Checking the key assumption [*]

It might be worth making explicit that the output format may not be very useful if any key name contains a period, so it might be worth checking that this is indeed the case, e.g. as follows:

[.. | objects | keys_unsorted[]]
| map(select(index(".")))
| unique[]

If your jq does not have tostream

paths as $path
| getpath($path) 
| strings
| "\"\($path|join("."))\" = \"\(.)\";"

_{[*] pun intended}

• millerf: Hahaha...Glad to see some jokes on this website... I was missing it :)
• millerf: thanks a lot it has been very useful. FYI, JSON objects are all well formatted, and there is no key with a '.'
• millerf: Now I need to do the reverse, form "string format to JSON, with recreating the objects. I'll ping you if I don't succeed. Thanks again.