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Function Reference

The functions section of a function library manifest defines the functions the library exposes. It's a map where each key is a function name and each value describes that function's parameters, return type, and execution characteristics.

Example

The following example declares a function that capitalizes text:

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Function fields

A function has the following fields:

Field	Required	Description
`parameters`	No	Array of parameter definitions. Maximum 10. Defaults to no parameters.
`returns`	No	Return type definition. Defaults to void.
`async`	No	Whether the function returns a Promise. Defaults to `false`.
`displayName`	No	Name of the function shown in the editor.
`description`	No	Function description.

Parameter fields

Each entry in parameters describes one argument the function accepts:

Field	Required	Description
`dataType`	Yes	The type of value the parameter accepts.
`displayName`	No	Name of the parameter shown in the editor.
`description`	No	Parameter description.
`optional`	No	Whether the parameter is optional. Only trailing parameters can be optional because JavaScript arguments are positional. Defaults to `false`.
`defaultValue`	No	Default the editor shows as a hint. Not passed at runtime, so your implementation must handle the missing value. Used only when `optional` is `true`.
`arrayItems`	When `dataType` is `arrayItems`	Defines what elements in the array look like.
`data`	When `dataType` is `data`	Defines the fields inside the nested object.
`function`	When `dataType` is `function`	Defines the parameters and return type of a callback parameter.
`textEnum`	When `dataType` is `textEnum`	List of allowed string options.
`link`	When `dataType` is `link`	Configuration for the link parameter, such as supported link types.

Optional parameters

Set optional to true to make a parameter optional. Only trailing parameters can be optional because JavaScript arguments are positional. Use defaultValue to give the editor a hint to display for the missing value.

The following example declares roundNumber with an optional parameter and a default value:

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Arrays

For array parameters, set dataType to 'arrayItems'. Then define the array elements under arrayItems.item.

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Nested objects

For complex object parameters, set dataType to 'data'. Then define each field of the object under data.items.

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Text enums

For a fixed set of string options, set dataType to 'textEnum' and list the choices under textEnum.options.

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Callback parameters

A parameter can itself be a function. Set its dataType to 'function', then describe the callback's parameters and return type under function.

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Link parameters

For a parameter that accepts a navigation link, set dataType to 'link'. The optional link field restricts which kinds of links are allowed. For the available fields, see Link.

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Return type fields

The returns field describes a function's return value:

Field	Required	Description
`dataType`	Yes	The type of value this function returns.
`displayName`	No	Name of the return value shown in the editor.
`description`	No	Description of the return value.
`arrayItems`	When `dataType` is `arrayItems`	Defines what elements in the returned array look like.
`data`	When `dataType` is `data`	Defines the fields inside the returned nested object.
`function`	When `dataType` is `function`	Defines the parameters and return type of the returned callback.
`textEnum`	When `dataType` is `textEnum`	List of allowed string options.
`link`	When `dataType` is `link`	Configuration for the returned link, such as supported link types.

Void functions

If a function doesn't return a value, omit returns.

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Async functions

Set async to true for a function whose implementation returns a Promise. The returns field describes the resolved value's type, not the Promise.

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