Merge or update a JSONGrammar

from __future__ import annotations

import contextlib
from copy import deepcopy

from gemseo.core.grammars.errors import InvalidDataError
from gemseo.core.grammars.json_grammar import JSONGrammar

Create the JSON grammars

The first grammar has the elements name1 and name2 that shall be integers. The second grammar has the elements name2 and name3 that shall be strings.

grammar_1 = JSONGrammar("grammar_1")
grammar_1.update_from_file("grammar_1.json")

grammar_2 = JSONGrammar("grammar_2")
grammar_2.update_from_file("grammar_2.json")

Keep a pristine copy of the first grammar such that we can experiment more than once on it.

grammar_1_copy = deepcopy(grammar_1)

Update without merge

By default, the update method acts like for a dictionary, i.e. an already existing key has its value overriden. Here the value for the element name2 is now string.

grammar_1.update(grammar_2)
grammar_1

Grammar name: grammar_1

• Required elements:
• Optional elements:
  • name1:
    • Type: integer
    • Default: N/A
  • name2:
    • Type: string
    • Default: N/A
  • name3:
    • Type: string
    • Default: N/A

On validation, the allowed type is only the one from the second grammar.

with contextlib.suppress(InvalidDataError):
    grammar_1.validate({"name2": 0})

grammar_1.validate({"name2": "a string"})

ERROR - 16:23:05: Grammar grammar_1: validation failed.
ERROR - 16:23:05: error: data.name2 must be string

Update with merge

First use the initial grammar from its copy.

grammar_1 = grammar_1_copy

When merging elements, an already existing element of the grammar will have both the old and the new value.

grammar_1.update(grammar_2, merge=True)
grammar_1

Grammar name: grammar_1

• Required elements:
• Optional elements:
  • name1:
    • Type: integer
    • Default: N/A
  • name2:
    • Type: ['integer', 'string']
    • Default: N/A
  • name3:
    • Type: string
    • Default: N/A

On validation, the allowed types can be any of the types from the original grammars, here either integer or string.

grammar_1.validate({"name2": 0})
grammar_1.validate({"name2": "a string"})