PoC: move onRequest from prehandler to get and post handlers

Author: Andrew-Folga

docs/PLUGIN_OPTIONS.md

@@ -84,9 +84,8 @@ If provided, the `onRequest` plugin option will be invoked on each request to an
 ```ts
 export type OnRequestCallback = (
   request: AnyFormRequest,
-  params: FormParams,
-  definition: FormDefinition,
-  metadata: FormMetadata
+  h: ResponseToolkit,
+  context: FormContext
 ) => void
 ```
 
@@ -96,12 +95,13 @@ Here's an example of how it could be used to secure access to forms:
 await server.register({
   plugin,
   options: {
-    onRequest: (request , params, definition, metadata) => {
-        const { auth } = request
+    onRequest: (request , h, context) => {
+      const redirectUrl = mapStatusToUrl(applicationStatus, grantCode)
+      if (request.path === redirectUrl) {
+        return h.continue
+      }
 
-        if (!auth.isAuthenticated) {
-          throw Boom.unauthorized()
-        }
+      return h.redirect(redirectUrl).takeover()
       }
   }
 })

src/server/plugins/engine/plugin.ts

@@ -34,7 +34,8 @@ export const plugin = {
       saveAndExit,
       nunjucks: nunjucksOptions,
       viewContext,
-      preparePageEventRequestOptions
+      preparePageEventRequestOptions,
+      onRequest
     } = options
 
     const cacheService =
@@ -83,7 +84,8 @@ export const plugin = {
       ...getQuestionRoutes(
         getRouteOptions,
         postRouteOptions,
-        preparePageEventRequestOptions
+        preparePageEventRequestOptions,
+        onRequest
       ),
       ...getRepeaterSummaryRoutes(getRouteOptions, postRouteOptions),
       ...getRepeaterItemDeleteRoutes(getRouteOptions, postRouteOptions),

src/server/plugins/engine/routes/index.ts

@@ -23,6 +23,7 @@ import * as defaultServices from '~/src/server/plugins/engine/services/index.js'
 import {
   type AnyFormRequest,
   type FormContext,
+  type OnRequestCallback,
   type PluginOptions
 } from '~/src/server/plugins/engine/types.js'
 import {
@@ -33,6 +34,7 @@ import {
 export async function redirectOrMakeHandler(
   request: AnyFormRequest,
   h: FormResponseToolkit,
+  onRequest: OnRequestCallback | undefined,
   makeHandler: (
     page: PageControllerClass,
     context: FormContext
@@ -69,6 +71,14 @@ export async function redirectOrMakeHandler(
   const relevantPath = page.getRelevantPath(request, context)
   const summaryPath = page.getSummaryPath()
 
+  // Call the onRequest callback if it has been supplied
+  if (onRequest) {
+    const result = await onRequest(request, h as ResponseToolkit, context)
+    if (result) {
+      return result // no need to check for `isTakeover`, TypeScript is happy
+    }
+  }
+
   // Return handler for relevant pages or preview URL direct access
   if (relevantPath.startsWith(page.path) || context.isForceAccess) {
     return makeHandler(page, context)
@@ -89,7 +99,7 @@ export function makeLoadFormPreHandler(server: Server, options: PluginOptions) {
   // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition -- hapi types are wrong
   const prefix = server.realm.modifiers.route.prefix ?? ''
 
-  const { services = defaultServices, controllers, onRequest } = options
+  const { services = defaultServices, controllers } = options
 
   const { formsService } = services
 
@@ -166,11 +176,6 @@ export function makeLoadFormPreHandler(server: Server, options: PluginOptions) {
       server.app.models.set(key, item)
     }
 
-    // Call the onRequest callback if it has been supplied
-    if (onRequest) {
-      onRequest(request, params, item.model.def, metadata)
-    }
-
     // Assign the model to the request data
     // for use in the downstream handler
     request.app.model = item.model

src/server/plugins/engine/routes/questions.ts

@@ -26,6 +26,7 @@ import {
 import {
   type AnyFormRequest,
   type FormContext,
+  type OnRequestCallback,
   type PreparePageEventRequestOptions
 } from '~/src/server/plugins/engine/types.js'
 import {
@@ -74,7 +75,8 @@ async function handleHttpEvent(
 }
 
 export function makeGetHandler(
-  preparePageEventRequestOptions?: PreparePageEventRequestOptions
+  preparePageEventRequestOptions?: PreparePageEventRequestOptions,
+  onRequest?: OnRequestCallback
 ) {
   return function getHandler(request: FormRequest, h: FormResponseToolkit) {
     const { params } = request
@@ -83,75 +85,86 @@ export function makeGetHandler(
       return dispatchHandler(request, h)
     }
 
-    return redirectOrMakeHandler(request, h, async (page, context) => {
-      // Check for a page onLoad HTTP event and if one exists,
-      // call it and assign the response to the context data
-      const { events } = page
-      const { model } = request.app
+    return redirectOrMakeHandler(
+      request,
+      h,
+      onRequest,
+      async (page, context) => {
+        // Check for a page onLoad HTTP event and if one exists,
+        // call it and assign the response to the context data
+        const { events } = page
+        const { model } = request.app
 
-      if (!model) {
-        throw Boom.notFound(`No model found for /${params.path}`)
-      }
+        if (!model) {
+          throw Boom.notFound(`No model found for /${params.path}`)
+        }
 
-      if (events?.onLoad && events.onLoad.type === 'http') {
-        await handleHttpEvent(
-          request,
-          page,
-          context,
-          events.onLoad,
-          model,
-          preparePageEventRequestOptions
-        )
-      }
+        if (events?.onLoad && events.onLoad.type === 'http') {
+          await handleHttpEvent(
+            request,
+            page,
+            context,
+            events.onLoad,
+            model,
+            preparePageEventRequestOptions
+          )
+        }
 
-      return page.makeGetRouteHandler()(request, context, h)
-    })
+        return page.makeGetRouteHandler()(request, context, h)
+      }
+    )
   }
 }
 
 export function makePostHandler(
-  preparePageEventRequestOptions?: PreparePageEventRequestOptions
+  preparePageEventRequestOptions?: PreparePageEventRequestOptions,
+  onRequest?: OnRequestCallback
 ) {
   return function postHandler(
     request: FormRequestPayload,
     h: FormResponseToolkit
   ) {
     const { query } = request
 
-    return redirectOrMakeHandler(request, h, async (page, context) => {
-      const { pageDef } = page
-      const { isForceAccess } = context
-      const { model } = request.app
-      const { events } = page
+    return redirectOrMakeHandler(
+      request,
+      h,
+      onRequest,
+      async (page, context) => {
+        const { pageDef } = page
+        const { isForceAccess } = context
+        const { model } = request.app
+        const { events } = page
 
-      // Redirect to GET for preview URL direct access
-      if (isForceAccess && !hasFormComponents(pageDef)) {
-        return proceed(request, h, redirectPath(page.href, query))
-      }
+        // Redirect to GET for preview URL direct access
+        if (isForceAccess && !hasFormComponents(pageDef)) {
+          return proceed(request, h, redirectPath(page.href, query))
+        }
 
-      if (!model) {
-        throw Boom.notFound(`No model found for /${request.params.path}`)
-      }
+        if (!model) {
+          throw Boom.notFound(`No model found for /${request.params.path}`)
+        }
 
-      const response = await page.makePostRouteHandler()(request, context, h)
+        const response = await page.makePostRouteHandler()(request, context, h)
 
-      if (
-        events?.onSave &&
-        events.onSave.type === 'http' &&
-        isSuccessful(response)
-      ) {
-        await handleHttpEvent(
-          request,
-          page,
-          context,
-          events.onSave,
-          model,
-          preparePageEventRequestOptions
-        )
-      }
+        if (
+          events?.onSave &&
+          events.onSave.type === 'http' &&
+          isSuccessful(response)
+        ) {
+          await handleHttpEvent(
+            request,
+            page,
+            context,
+            events.onSave,
+            model,
+            preparePageEventRequestOptions
+          )
+        }
 
-      return response
-    })
+        return response
+      }
+    )
   }
 }
 
@@ -164,13 +177,14 @@ function isSuccessful(response: ResponseObject): boolean {
 export function getRoutes(
   getRouteOptions: RouteOptions<FormRequestRefs>,
   postRouteOptions: RouteOptions<FormRequestPayloadRefs>,
-  preparePageEventRequestOptions?: PreparePageEventRequestOptions
+  preparePageEventRequestOptions?: PreparePageEventRequestOptions,
+  onRequest?: OnRequestCallback
 ): (ServerRoute<FormRequestRefs> | ServerRoute<FormRequestPayloadRefs>)[] {
   return [
     {
       method: 'get',
       path: '/{slug}',
-      handler: makeGetHandler(preparePageEventRequestOptions),
+      handler: makeGetHandler(preparePageEventRequestOptions, onRequest),
       options: {
         ...getRouteOptions,
         validate: {
@@ -197,7 +211,7 @@ export function getRoutes(
     {
       method: 'get',
       path: '/{slug}/{path}/{itemId?}',
-      handler: makeGetHandler(preparePageEventRequestOptions),
+      handler: makeGetHandler(preparePageEventRequestOptions, onRequest),
       options: {
         ...getRouteOptions,
         validate: {
@@ -212,7 +226,7 @@ export function getRoutes(
     {
       method: 'get',
       path: '/preview/{state}/{slug}/{path}/{itemId?}',
-      handler: makeGetHandler(preparePageEventRequestOptions),
+      handler: makeGetHandler(preparePageEventRequestOptions, onRequest),
       options: {
         ...getRouteOptions,
         validate: {
@@ -228,7 +242,7 @@ export function getRoutes(
     {
       method: 'post',
       path: '/{slug}/{path}/{itemId?}',
-      handler: makePostHandler(preparePageEventRequestOptions),
+      handler: makePostHandler(preparePageEventRequestOptions, onRequest),
       options: {
         ...postRouteOptions,
         validate: {
@@ -250,7 +264,7 @@ export function getRoutes(
     {
       method: 'post',
       path: '/preview/{state}/{slug}/{path}/{itemId?}',
-      handler: makePostHandler(preparePageEventRequestOptions),
+      handler: makePostHandler(preparePageEventRequestOptions, onRequest),
       options: {
         ...postRouteOptions,
         validate: {