Option for making fields required by default when writing a schema

[Yzen90]

Hello, would it be possible to add an option to make fields required by default when generating a JSON schema?

Something like this:

struct MyObject {
  struct Child {
      string a_field;
  } child;
};

// Set `child` and `a_field` as required in the generated schema:
auto schema = glz::write_json_schema<MyObject, glz::opts{.require_all_fields = true}>();

Thanks

[stephenberry]

This would be an excellent compile time option. I have plans to greatly improve the compile time option handling in Glaze, so I will probably wait until that is completed before adding this feature, as every new option currently makes template errors harder to read. I'll create an issue from this discussion to add this in the future.

[stephenberry]

This feature is was merged some time ago. You can use glz::opts{.error_on_missing_keys = true} when calling write_json_schema to mark all non-nullable fields as required in the generated schema.

Example

#include <glaze/glaze.hpp>

struct Address
{
   std::string street{};
   std::string city{};
   std::optional<std::string> apartment{}; // nullable - will NOT be required
};

struct Person
{
   std::string name{};
   int age{};
   std::optional<std::string> nickname{}; // nullable - will NOT be required
   Address address{};
};

int main()
{
   // Generate schema with all non-nullable fields marked as required
   auto schema = glz::write_json_schema<Person, glz::opts{.error_on_missing_keys = true}>().value_or("error");

   std::cout << glz::prettify_json(schema) << '\n';
}

Output

{
   "type": ["object"],
   "properties": {
      "name": { "$ref": "#/$defs/std::string" },
      "age": { "$ref": "#/$defs/int32_t" },
      "nickname": { "$ref": "#/$defs/std::optional<std::string>" },
      "address": { "$ref": "#/$defs/Address" }
   },
   "additionalProperties": false,
   "$defs": {
      "std::string": { "type": ["string"] },
      "int32_t": { "type": ["integer"], "minimum": -2147483648, "maximum": 2147483647 },
      "std::optional<std::string>": { "type": ["string", "null"] },
      "Address": {
         "type": ["object"],
         "properties": {
            "street": { "$ref": "#/$defs/std::string" },
            "city": { "$ref": "#/$defs/std::string" },
            "apartment": { "$ref": "#/$defs/std::optional<std::string>" }
         },
         "additionalProperties": false,
         "required": ["street", "city"]
      }
   },
   "required": ["name", "age", "address"],
   "title": "Person"
}

This works recursively for nested objects as well.