Default value of field dependent on drop down not being updated

[IanTurtle]

Prerequisites

• I have searched the existing issues
• I understand that providing a SSCCE example is tremendously useful to the maintainers.
• I have read the documentation
• Ideally, I'm providing a sample JSFiddle or a shared playground link demonstrating the issue.

What theme are you using?

core

Version

Playground

Current Behavior

In a form with two fields, where one is a dropdown of different options and a second is dependent on the other. The second field changes values depending on the option second. If you then select a different option from the dropdown menu, the value of the second field does not change to the different value.

Expected Behavior

In a form with two fields, where one is a dropdown of different options and a second is dependent on the other. The second field changes values depending on the option second. If you then select a different option from the dropdown menu, the value of the second field would change to the different value.

Steps To Reproduce

In the React JSON Schema playground, create a form using the following payload

{
    "title": "Optional Components",
    "required": [
      "component"
    ],
    "properties": {
      "component": {
        "title": "Component",
        "type": "object",
        "properties": {
          "component": {
            "title": "Component",
            "type": "string",
            "enum": [
              "value1",
              "value2"
            ]
          }
        },
        "required": [
          "component"
        ],
        "dependencies": {
          "component": {
            "oneOf": [
              {
                "properties": {
                  "component": {
                    "enum": [
                      "value1"
                    ]
                  },
                  "template": {
                    "type": "string",
                    "default": "abc"
                  }
                }
              },
              {
                "properties": {
                  "component": {
                    "enum": [
                      "value2"
                    ]
                  },
                  "template": {
                    "type": "string",
                    "default": "def"
                  }
                }
              }
            ]
          }
        }
      }
    }
  }

Select value1 from the Component menu and notice the value of the template field is abc

Then select value2 from the Component menu and notice the value of the template field is abc (and not the expected def)

Environment

Playground

Anything else?

Playground link here

[lucaswiman]

I'm running into similar issues. I think the cause is here:

react-jsonschema-form/packages/utils/src/schema/getDefaultFormState.ts

Lines 106 to 141 in b63ec99

	if (isObject(defaults) && isObject(schema.default)) {
	// For object defaults, only override parent defaults that are defined in
	// schema.default.
	defaults = mergeObjects(
	defaults!,
	schema.default as GenericObjectType
	) as T;
	} else if (DEFAULT_KEY in schema) {
	defaults = schema.default as unknown as T;
	} else if (REF_KEY in schema) {
	// Use referenced schema defaults for this node.
	const refSchema = findSchemaDefinition<S>(schema[REF_KEY]!, rootSchema);
	return computeDefaults<T, S>(
	validator,
	refSchema,
	defaults,
	rootSchema,
	formData as T,
	includeUndefinedValues
	);
	} else if (DEPENDENCIES_KEY in schema) {
	const resolvedSchema = resolveDependencies(
	validator,
	schema,
	rootSchema,
	formData
	);
	return computeDefaults<T, S>(
	validator,
	resolvedSchema,
	defaults,
	rootSchema,
	formData as T,
	includeUndefinedValues
	);
	} else if (isFixedItems(schema)) {

When computing the defaults, once one set of defaults is determined, it only recurses down to non-dependent properties.

[lucaswiman]

Looking into this a bit more, it's less clear to me that this is a bug. FormData would need to record the source of every field (set from a default or entered data). Slightly altering the example playground with "enum": ["abc"] or "const": "abc" yields the desired behavior (see playground link).

[lucaswiman]

The example I've been looking at is here, with a recursive definition with dependencies.

To reproduce on that playground:

• Select attr -> foo
• Then update node_type -> Not
• Child node_type does not default to "AtttributeNode"

A related schema (which should be semantically equivalent) puts the default on the node_type property (link). Here following the same procedure refuses to update the invalid child.node_type value in formData (even though the default is displayed in the UI element), and doesn't display the attr element.

[heath-freenome]

I'm wondering if this is a very complicated example of #2944 in that our oneOf code isn't properly selecting the correct one-of