Arrays

Arrays are defined with a type equal to array, and array items' schemas are specified in the items keyword.

Arrays of a single field

Arrays of a single field type can be specified as follows:

const schema = {
  type: "array",
  items: {
    type: "string"
  }
};

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

Arrays of objects

Arrays of objects can be specified as follows:

const schema = {
  type: "array",
  items: {
    type: "object",
    properties: {
        name: {
            type: "string"
        }
    }
  }
};

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

uiSchema for array items

To specify a uiSchema that applies to array items, specify the uiSchema value within the items property:

const schema = {
  type: "array",
  items: {
    type: "string"
  }
};

const uiSchema = {
  items: {
    "ui:widget": "textarea"
  }
};

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

The additionalItems keyword

The additionalItems keyword allows the user to add additional items of a given schema. For example:

const schema = {
  type: "array",
  items: {
    type: "string"
  },
  additionalItems: {
    type: "boolean"
  }
};

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

Array item options

orderable option

Array items are orderable by default, and react-jsonschema-form renders move up/down buttons alongside them. The uiSchema orderable options allows you to disable ordering:

const schema = {
  type: "array",
  items: {
    type: "string"
  }
};

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

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

addable option

If either items or additionalItems contains a schema object, an add button for new items is shown by default. You can turn this off with the addable option in uiSchema:

const schema = {
  type: "array",
  items: {
    type: "string"
  }
};

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

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

removable option

A remove button is shown by default for an item if items contains a schema object, or the item is an additionalItems instance. You can turn this off with the removable option in uiSchema:

const schema = {
  type: "array",
  items: {
    type: "string"
  }
};

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

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

Multiple-choice list

The default behavior for array fields is a list of text inputs with add/remove buttons. There are two alternative widgets for picking multiple elements from a list of choices. Typically this applies when a schema has an enum list for the items property of an array field, and the uniqueItems property set to true.

Example:

const schema = {
  type: "array",
  title: "A multiple-choice list",
  items: {
    type: "string",
    enum: ["foo", "bar", "fuzz", "qux"],
  },
  uniqueItems: true
};

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

By default, this will render a multiple select box. If you prefer a list of checkboxes, just set the uiSchema ui:widget directive to checkboxes for that field:

const schema = {
  type: "array",
  title: "A multiple-choice list",
  items: {
    type: "string",
    enum: ["foo", "bar", "fuzz", "qux"],
  },
  uniqueItems: true
};

const uiSchema = {
  "ui:widget": "checkboxes"
};

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

Specifying the minimum or maximum number of items

Note that when an array property is marked as required, an empty array is considered valid. If the array needs to be populated, you can specify the minimum number of items using the minItems property.

Example:

const schema = {
  type: "array",
  minItems: 2,
  title: "A multiple-choice list",
  items: {
    type: "string",
    enum: ["foo", "bar", "fuzz", "qux"],
  },
  uniqueItems: true
};

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

You can also specify the maximum number of items in an array using the maxItems property.

Inline checkboxes

By default, checkboxes are stacked. If you prefer them inline, set the inline property to true:

const schema = {
  type: "array",
  minItems: 2,
  title: "A multiple-choice list",
  items: {
    type: "string",
    enum: ["foo", "bar", "fuzz", "qux"],
  },
  uniqueItems: true
};

const uiSchema = {
  "ui:widget": "checkboxes",
  "ui:options": {
    inline: true
  }
};

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