> For the complete documentation index, see [llms.txt](https://docs.klai.studio/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.klai.studio/v1/reference/actions-processor/actions_overview/function-1.md).

# function

Run JavaScript in an action.

#### Function Action Object

| Key      | Description                                                                      |
| -------- | -------------------------------------------------------------------------------- |
| action   | `'function'`                                                                     |
| function | `string` javascript to be run. This JS is converted into a function and executed |

**Note:** The `function` key can also be used in any other action that originates from the client. This means actions generated in a hook call do not get the function run when arriving at the server.

Javascript is placed on a single JSON value line, you must separate commands with a semicolon. Proper JSON escaping will always need to be applied.

#### Uses:

Functions are great for injecting small logic into any work flow.

* build a custom string and edit the `url` value for a `path` action

**Contexts** `function` code executes with slightly different context to other Java Script in BetterForms.

| To Get        | Reference This | Description                                                                                                                                                     |
| ------------- | -------------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| window        | `window`       | The Browser JS window object, good for environmental control                                                                                                    |
| formSchema    | `formSchema`   | Containing other sub objects like ~~model~~ etc                                                                                                                 |
| model         | `model`        | This is the uppermost model object regardless of sub objects like accordions etc.                                                                               |
| app           | `app`          | This will access the global `app` data model                                                                                                                    |
| action object | `action`       | The whole `action` object that contains this function. eg: `action.options.path` Some BetterForms Elements will merge additional options into the`options` key. |

| as of ver 0.7.302 |                           |
| ----------------- | ------------------------- |
| Site app          | app (site app data model) |

```
**Example**
// This will change the nameFirst value to Jerome
[
  {
    "action": "function",
    "function": "debugger; formSchema.model.nameFirst = 'Jerome' "
    "options": {
      // ... additional params etc you may want.
    }
  }
]
```

Code Style

Function results returned with a `return` statement are ignored.

**Contexts** `function` code executes with the context of the currently active form, if you have a modal displayed, then code runs in that modal's context.