Feature request: automatically add nested defaults about python-fastjsonschema HOT 7 OPEN

Not automatically, but you can always define default on the foo object as well, that is:

schema = {
    "type": "object",
    "properties": {
        "foo": {
            "type": "object",
            "default": {"bar": "bar"},
            "properties": {
                "bar": {
                    "type": "string",
                    "default": "bar"
                }
            }
        },
    },
    "required": [],
    "additionalProperties": False
}

Doing this automatically might be quite expensive call, and also surprising. Sometimes you might not want the default to be set automatically for foo, but once foo is defined, you want to just ensure it contains required properties.

Would this suggestion work for you?

If not, I might have an idea to provide some special value (fastjsonschema.NESTED_DEFAULT, for example), that could indicate that an algorithm should make an object and fill child defaults too. But it deviates from the specification, so would rather avoid it unless necessary.

from python-fastjsonschema.

I ended up doing what you suggested, but I don't love it as a solution. I think it violates DRY -- if we update the underlying schema for bar, we also need to update foo, and this may be easy to forget or mess up for more complicated schema types. I'm concerned that these sorts of errors are also uniquely tricky to track down, since defaults are rarely the first thing a dev may think to check

That said, I agree that the spec is not fleshed out here -- anything related to default behavior feels surprising and unexpected for some set of usecases

from python-fastjsonschema.

I agree that it can violite DRY. But at the same time it is more explicit I would say.

What would you say on my suggestion above? It could look like this:

schema = {
    "type": "object",
    "properties": {
        "foo": {
            "type": "object",
            "default": {"bar": fastjsonschema.NESTED_DEFAULT},
            "properties": {
                "bar": {
                    "type": "string",
                    "default": "bar"
                }
            }
        },
    },
    "required": [],
    "additionalProperties": False
}

from python-fastjsonschema.

While it would be very expensive, maybe it would be nice, if fastjsonschema provides an additional function add_defaults_recursively (as you can see I am just GREAT at naming things...), that recursively adds defaults but must be called explicitly by the user so they know what they are signing up for.

In case you, @horejsek are interested, I could cook up a PR, but probably not before next week.

from python-fastjsonschema.

Also: I just realized that if I have an array of objects and the object contains properties with defaults, these ARE added.

Is the general rule the following?

EDIT: Oh, obviously not as the thread topic shows. But apparently in arrays nested defaults are set.

"The topmost layer of defaults is added"?

from python-fastjsonschema.