runUtilityHook

Calls the scoped onUtility server hook.

runUtilityHook is a browser-side action that packages a payload and sends it to FileMaker through formsService.onUtility.

Action Shape

Key	Type	Description
action	runUtilityHook
options	object	Additional values passed into the `hookPackage` that FileMaker receives
options.hookSetName	string (optional)	If passed, this overrides the page's default scoped hook set name. This is useful when you want to trigger the onUtility server hook from one page but route it through another scoped hook set. It is also useful for global named actions, because they are not associated with a specific form. Helper File >Ver 0.1.2
options.model	object	Optional custom outgoing model payload. If supplied, it replaces the normal outgoing page model for this hook call.
options.modelFilterKeys	array	Optional list of model keys to keep from the current page model before sending the hook payload.
options.query	object	Optional query override. If omitted, BetterForms sends the current page query parameters.

{
  "action": "runUtilityHook",
  "options": {
    "type": "save",
    "someKey": "some passed info"
  }
}

In the example above, type is just an arbitrary key you can inspect in FileMaker to branch between different onUtility behaviors for the same page or hook set.

You can inspect the full action object in FileMaker under hookPackage.

Payload Behavior

By default, BetterForms starts from the current page schema/model payload.

If the page does not have Send full schema in utility hooks enabled, BetterForms trims the outgoing payload and keeps only a lightweight form object with the current hookSetName.

For payload-size details, see Reducing Payload Size.

Response Behavior

When FileMaker returns from onUtility, BetterForms can apply:

• returned actions
• returned model
• returned app
• returned pages / form updates

Returned actions are inserted back into the active action thread.

Model Merge Rules

If the response includes result.model:

• BetterForms defaults to merge behavior unless state.modelUpdateMode is explicitly set
• options.model and options.modelFilterKeys also mark the request for merge behavior
• explicit state.modelUpdateMode = "replace" is required when you want a full model replacement

This preserves client-only reactive keys while still letting FileMaker update the page model.

App Sync

If a returned model key is configured with appSync, BetterForms keeps the page model and app model aligned.

When both the returned app object and returned model object provide the same appSync key, the returned app value wins for the final synced value.

Hook Boundary

runUtilityHook is an action, not a hook by itself:

• the action runs in the browser
• BetterForms packages the payload
• the server-side onUtility hook runs in FileMaker

If you want browser-side workflows such as onFormLoad or onAppLoad, see Lifecycle Hooks.