Objects

Object properties

Objects are defined with a type equal to object and properties specified in the properties keyword.

const schema = {
  "title": "My title",
  "description": "My description",
  "type": "object",
  "properties": {
    "name": {
      "type": "string"
    },
    "age": {
      "type": "number"
    }
  }
};

render((
  <Form schema={schema} />
), document.getElementById("app"));

Required properties

You can specify which properties are required using the required attribute:

const schema = {
  "title": "My title",
  "description": "My description",
  "type": "object",
  "properties": {
    "name": {
      "type": "string"
    },
    "age": {
      "type": "number"
    }
  },
  "required": ["name"]
};

render((
  <Form schema={schema} />
), document.getElementById("app"));

Specifying property order

Since the order of object properties in Javascript and JSON is not guaranteed, the uiSchema object spec allows you to define the order in which properties are rendered using the ui:order property:

const schema = {
  type: "object",
  properties: {
    foo: {type: "string"},
    bar: {type: "string"}
  }
};

const uiSchema = {
  "ui:order": ["bar", "foo"]
};

render((
  <Form schema={schema}
        uiSchema={uiSchema} />
), document.getElementById("app"));

If a guaranteed fixed order is only important for some fields, you can insert a wildcard "*" item in your ui:order definition. All fields that are not referenced explicitly anywhere in the list will be rendered at that point:

const uiSchema = {
  "ui:order": ["bar", "*"]
};

Additional properties

The additionalProperties keyword allows the user to add properties with arbitrary key names. Set this keyword equal to a schema object:

const schema = {
  "type": "object",
  "properties": {
    "name": {
      "type": "string"
    }
  },
  "additionalProperties": {
    "type": "number",
    "enum": [1, 2, 3]
  }
};

render((
  <Form schema={schema} />
), document.getElementById("app"));

In this way, an add button for new properties is shown by default.

You can also define uiSchema options for additionalProperties by setting the additionalProperties attribute in the uiSchema.

expandable option

You can turn support for additionalProperties off with the expandable option in uiSchema:

const uiSchema = {
  "ui:options":  {
    expandable: false
  }
};