radio

A radio field allows a list of options where a user can select one value.

Module field definition

// Configuring the `animalType` field in a module's `fields.add` subsection:
animalType: {
  label: 'Type of animal',
  type: 'radio',
  choices: [
    {
      label: 'Mammals 🦧',
      value: 'mammals'
    },
    {
      label: 'Fish 🐠',
      value: 'fish'
    },
    {
      label: 'Birds 🦜',
      value: 'birds'
    },
    {
      label: 'Reptiles 🦎',
      value: 'reptiles'
    },
    {
      label: 'Amphibians 🐸',
      value: 'amphibians'
    }
 ]
}

Settings

Required

Property	Type	Default	Description
choices	Array/String	n/a	An array of options that the editor can select from, or a method name that returns them. See below.
label	String	n/a	Sets the visible label for the field in the UI
type	String	n/a	Specifies the field type (radio for this type)

Optional

Property	Type	Default	Description
def	Varies	n/a	The default value for the field. Must be from the defined choices' values.
following	String/Array	n/a	The name of a field or an array of field names that can be used to generate dynamic choices for this field.
help	String	n/a	Help text for the content editor
htmlHelp	String	n/a	Help text with support for HTML markup
if	Object	{}	Conditions to meet before the field is active. See the guide for details.
requiredIf	Object	{}	Conditions to meet before the field is required. See the guide for details.
hidden	Boolean	false	If true, the field is hidden
required	Boolean	false	If true, the field is mandatory
readOnly	Boolean	false	If true, prevents the user from editing the field value

following

The following option is used when adding field choices that depend on the value of another field in the schema by passing a string representing a method name to the choices option. It should be set to the name of a field or an array of field names that will be used to dynamically create choices based on the value of those named field(s).

If this field is nested in an array or object field and is following a field in the parent object, then the name of the field should be prefixed with a <, e.g. following: '<title'. This hoisting also works if the field is following a field in the parent object from a grand-child array or object that is nested within a child array or object using <<. This pattern can be extended for additional levels of nesting.

The value(s) of the followed field(s) will be used to create an object with properties composed of the followed schema name for each key, and the current value of that field as value. This object will be passed to the dynamic choices method (see below). Note that the property key in the object is the same as the value passed to the following field, including any prepended <.

choices configuration

The choices setting in checkboxes, radio, or select fields configures the options that a user will see in the interface and the values that the server will allow in validation. The choices value is an array of objects with label and value properties, or a string ending with () representing a method(self) in your module. See below for more details.

• value is used in the field's database value
• label is the more human-readable version used in interfaces

Populating choices dynamically

What if the choices aren't known in advance or are dependent on the value of another schema field? Then you can fetch them dynamically.

First, set the choices option to the name of a method in your module. Pass the name of the method you'll implement on the server side as a string ending in (). e.g. choices: 'getChoices()' — do not pass a function.

Second, implement that method in your module so that it takes (req, data, following) arguments and return an array of choices in the usual format. You may use an async function, or return a promise that will resolve to the array. That means you can reach out to APIs using modules like axios or node-fetch, or make Apostrophe database queries.

The data argument is an object containing the parent's docId for further inspection by your function and is falsey if the document hasn't been published.

The following argument is an object containing the schema fields being followed as keys and the value of those fields as values. Note that the key will match the field name(s) in the following field array exactly. So if you are passing a parental schema field value in an object or array schema field, you need to include the prefixing < along with the name. See the following property description.

When your choices method is async, while calls to the method are debounced to keep the rate of calls reasonable, is usually a good idea to perform at least short-term caching in order to limit the impact on performance when editing.

module.exports = {
  extend: '@apostrophecms/piece-type',
  options: {
    label: 'Example'
  },
  fields: {
    add: {
      // other schema fields
      region: {
        type: 'select',
        label: 'Region',
        choices: [
          { label: 'North America', value: 'na' },
          { label: 'Europe', value: 'eu' }
        ]
      },
      cities: {
        type: 'radio',
        label: 'Favorite City',
        following: [ 'region' ],
        choices: 'getCities()'
      }
    }
  },
  methods(self) {
    return {
      // this method can be async
      getCities(req, { docId }, { region }) {
        // Define city choices based on the selected region
        const cityChoices = {
          na: [
            { label: 'New York', value: 'newYork' },
            { label: 'Los Angeles', value: 'losAngeles' },
            { label: 'Chicago', value: 'chicago' }
          ],
          eu: [
            { label: 'Paris', value: 'paris' },
            { label: 'Berlin', value: 'berlin' },
            { label: 'London', value: 'london' }
          ]
        };
        // Return the array of choices for the selected region
        return cityChoices[region] || [];
      }
    };
  }
};

Use in templates

Radio field data is stored as the string value property of the selected choice.

{{ data.piece.animalType }}