autogenerated json path

Hi,
im first time using json data type and i want to autogenerate it, because
im creating crawler which uses postgresql.

This is static example for one site where path should be automatically
generate
SELECT
file_name
,json_data#>>'{1,children,1,children,5,children,3,children,0,children,22,children,0,children,1,children,0,content}'
from src_data
where file_name ~ 'monitor.hr';

in case that i want to add into table another sites and their paths, i
would like to write query which automaticaly changes paths.
SELECT
file_name
,json_data#>>'{''||r.json_path ||''}'
,r.json_path
from src_data d,rules r
where file_name like r.file_name_prefix||'%';

is there any way to write this without writing functions which would slow
process?

--
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Viktor Bojović