Lifecycle Hooks

Lifecycle hooks are client-side workflow entry points, not FileMaker server hooks.

Use them when you want BetterForms to run named actions automatically at specific moments in the browser lifecycle.

For FileMaker developers, the key rule is:

• if BetterForms is calling your FileMaker script, that is a server hook

• if BetterForms is automatically running a named action in the browser, that is a lifecycle hook

At A Glance

Lifecycle Hook	Scope	When it runs
onAppLoad	App-wide	After the app/site loads in the browser
onFormLoad	Page-specific	After a page/form has loaded in the browser
onBeforeMount	Component	Before a custom component renders
onMount	Component	After a custom component renders to the DOM
onUpdated	Component	After a custom component updates
onBeforeDestroy	Component	Before a custom component is removed
onDestroyed	Component	After a custom component is removed

onAppLoad

onAppLoad is a global named action that runs after the app/site has loaded.

Typical uses:

• initialize app-wide browser-side state

• set up PWA behavior

• load UI libraries or feature flags

• run startup actions after a refresh

Notes:

• This is a client-side workflow, not a FileMaker server call.

• It is typically defined in app-level named actions.

• If needed, an onAppLoad workflow can still call the server by including runUtilityHook.

onFormLoad

onFormLoad is a page-level named action that runs after a form/page loads.

Typical uses:

• trigger browser-side setup for a page

• consume a token from the URL and run an auth flow

• kick off a page-specific action sequence after load

• run a runUtilityHook as part of the load sequence when the page needs server data

Notes:

• If actions are returned from onFormRequest, those are queued before onFormLoad.

• onFormLoad is a very common place to run auth-related actions like authVerify or token-based authLogin.

Component Lifecycle Hooks

Custom components support their own lifecycle hooks through component named actions.

onBeforeMount

Runs before the component renders and is useful for blocking setup work such as:

• loading external libraries

• preparing configuration

• doing work that must finish before the component displays

onMount

Runs after the component is rendered to the DOM.

Use it for:

• DOM-dependent initialization

• third-party library startup

• attaching behavior to rendered elements

onUpdated

Runs after component data changes and the component updates.

Use it for:

• syncing a library instance with new data

• updating UI integrations after state changes

onBeforeDestroy

Runs before the component is removed.

Use it for:

• cleanup work

• stopping listeners

• tearing down library instances

onDestroyed

Runs after the component is removed.

Use it for any final cleanup that should happen after teardown.

About onError

You may also see onError mentioned in some specialized frontend-tool or integration contexts.

For this docs section, treat it carefully:

• onError is not documented here as a general app-wide lifecycle hook in the same way as onAppLoad or onFormLoad

• when a specific feature provides its own onError callback or handler, document it with that feature

This avoids mixing generic lifecycle hooks with feature-specific error callbacks.

If your goal is app-level error behavior rather than a lifecycle trigger, see the existing error-handling references:

• BetterForms Error Pages API for app-level errorHandlers and custom /error page behavior

• function for function-action error handling and code 10501

Relationship To Server Hooks

Lifecycle hooks do not replace server hooks.

Instead, they often work together:

1. a lifecycle hook starts a browser-side workflow

2. that workflow may call runUtilityHook

3. the server hook runs in FileMaker

4. BetterForms resumes the client-side action flow

Related Pages

• Script Hooks

• Common Hooks

• Scoped Hooks

• BetterForms Error Pages API

• Named Actions (Action Scripts)

• Creating Components with Third-Party Libraries