Skill Settings

Skill settings provide the ability for users to configure a Skill using the command line or a web-based interface.

This is often used to:

  • Change default behaviors - such as the sound used for users alarms.
  • Authenticate with external services - such as Spotify
  • Enter longer data as text rather than by voice - such as the IP address of the users Home Assistant server.

Skill settings are completely optional.

Using settings in your Skill

Settings can be managed via command line, shipped by images or managed via a backend if ovos-core us configured to use one

When settings are fetched from the backend server, they are saved into a settings.json file. This file is automatically created when a Skill is loaded even if the Skill does not have any settings. Your Skill then accesses the settings from this file. Nowadays the file is located in the Skill's XDG_CONFIG_DIR (usually ~/config/mycroft/skills/<skillname>), however if a settings.json file already exists in the Skill's root directory (the deprecated location) that location is used for compatibility.

Reading settings

Skill settings are available on the MycroftSkill class and inherit from a Python Dict. This means that you can use it just like you would any other Python dictionary.

To access the show_time variable from our example above we would use the Dict.get method:

self.settings.get('show_time')

If the setting we are trying to access is not available, the get method will return None. Instead of assigning this to a variable and then testing for None, we can provide a default value as the second argument to the get method.

self.settings.get('show_time', False)

In this example, if the settings have not been received, or the show_time setting has not been assigned, it will return the default value False.

A few warnings

We recommend using the Dict.get method above rather than accessing the setting directly with:

self.settings['show_time']

Directly referencing the value may throw a KeyError if the setting has not yet been fetched from the server.

It is also important to note that the settings dictionary will not be available in your Skills __init__ method as this is setting up your Skills Class. You should instead use an initialize method which is called after the Skill is fully constructed and registered with the system.

Handling settings changes

OVOS will check for updates to a users settings regularly, both locally and on the configured backend.

To perform some action when settings are updated, you can register a callback function in your Skill.

def initialize(self):
  self.settings_change_callback = self.on_settings_changed
  self.on_settings_changed()

def on_settings_changed(self):
  show_time = self.settings.get('show_time', False)
  self.trigger_time_display(show_time)

In the example above, we have registered the on_settings_changed method to be our callback function. We have then immediately called the method to perform the relevant actions when the Skill is being initialized even though the Skills settings have not changed.

In the on_settings_changed method we have assigned the value of the show_time setting to a local variable. Then we have passed it as an argument to another method in our Skill that will trigger the display of the time based on its value.

Writing to settings

Your Skill can reassign a setting locally. To do this we assign a value like you would with any other dictionary key.

self.settings['show_time'] = True

The new value for the show_time setting will persist until a new setting is assigned locally by the Skill, or remotely if the user configured a backend

Define settings UI for a Skill

To define our Skills settings UI we use a settingsmeta.json or settingsmeta.yaml file. This file must be in the root directory of the Skill and must follow a specific structure.

Once settings have been defined using a settingsmeta file, they will be presented to the user in the configured backend or helper application

Example settingsmeta file

To see it in action, lets look at a simple example from the Date-Time Skill. First using the JSON syntax as a settingsmeta.json file:

{
    "skillMetadata": {
        "sections": [
            {
                "name": "Display",
                "fields": [
                    {
                        "name": "show_time",
                        "type": "checkbox",
                        "label": "Show digital clock when idle",
                        "value": "true"
                    }
                ]
            }
        ]
    }
}

Now, here is the same settings, as it would be defined with YAML in a settingsmeta.yaml file:

skillMetadata:
   sections:
      - name: Display
        fields:
          - name: show_time
            type: checkbox
            label: Show digital clock when idle
            value: "true"

Notice that the value of false is surrounded by "quotation marks". This is because OVOS expects a string of "true" or "false" rather than a Boolean.

Both of these files would result in the same settings block.

It is up to your personal preference which syntax you choose.

Structure of the settingsmeta file

Whilst the syntax differs, the structure of these two filetypes is the same. This starts at the top level of the file by defining a skillMetadata object. This object must contain one or more sections elements.

Sections

Each section represents a group of settings that logically sit together. This enables us to display the settings more clearly in the web interface for users.

In the simple example above we have just one section. However the Spotify Skill settings contains two sections. The first is for Spotify Account authentication, and the second section contains settings to define your default playback device.

Each section must contain a name attribute that is used as the heading for that section, and an Array of fields.

Fields

Each section has one or more fields. Each field is a setting available to the user. Each field takes four properties:

  • name (String)

    The name of the field is used by the Skill to get and set the value of the field. It will not usually be displayed to the user, unless the label property has not been set. * type (Enum)

    The data type of this field. The supported types are:

    • text: any kind of text
    • email: text validated as an email address
    • checkbox: boolean, True or False
    • number: text validated as a number
    • password: text hidden from view by default
    • select: a drop-down menu of options
    • label: special field to display text for information purposes only. No name or value is required for a label field.
    • label (String)

    The text to be displayed above the setting field. * value (String)

    The initial value of the field.

Examples for each type of field are provided in JSON and YAML at the end of this page.

SettingsMeta Examples

Label Field

skillMetadata:
   sections:
      - name: Label Field Example
        fields:
          - type: label
            label: This is descriptive text.

Text Field

skillMetadata:
   sections:
      - name: Text Field Example
        fields:
          - name: my_string
            type: text
            label: Enter any text
            value:

Email

skillMetadata:
   sections:
      - name: Email Field Example
        fields:
          - name: my_email_address
            type: email
            label: Enter your email address
            value:

Checkbox

skillMetadata:
   sections:
      - name: Checkbox Field Example
        fields:
          - name: my_boolean
            type: checkbox
            label: This is an example checkbox. It creates a Boolean value.
            value: "false"

Number

skillMetadata:
   sections:
      - name: Number Field Example
        fields:
          - name: my_number
            type: number
            label: Enter any number
            value: 7

Password

skillMetadata:
   sections:
      - name: Password Field Example
        fields:
          - name: my_password
            type: password
            label: Enter your password
            value:

Select

skillMetadata:
   sections:
      - name: Select Field Example
        fields:
          - name: my_selected_option
            type: select
            label: Select an option
            options: Option 1|option_one;Option 2|option_two;Option 3|option_three
            value: option_one