feat: improve error message for invalid API url

Resolves https://kolaente.dev/vikunja/frontend/issues/3680

src/components/misc/ready.vue

@@ -48,13 +48,14 @@ import Message from '@/components/misc/message.vue'
 import CustomTransition from '@/components/misc/CustomTransition.vue'
 import NoAuthWrapper from '@/components/misc/no-auth-wrapper.vue'
 
-import {ERROR_NO_API_URL} from '@/helpers/checkAndSetApiUrl'
+import {ERROR_NO_API_URL, InvalidApiUrlProvidedError, NoApiUrlProvidedError} from '@/helpers/checkAndSetApiUrl'
 import {useOnline} from '@/composables/useOnline'
 
 import {getAuthForRoute} from '@/router'
 
 import {useBaseStore} from '@/stores/base'
 import {useAuthStore} from '@/stores/auth'
+import {useI18n} from 'vue-i18n'
 
 const router = useRouter()
 const route = useRoute()
@@ -68,6 +69,8 @@ const online = useOnline()
 const error = ref('')
 const showLoading = computed(() => !ready.value && error.value === '')
 
+const {t} = useI18n()
+
 async function load() {
 	try {
 		await baseStore.loadApp()
@@ -77,7 +80,15 @@ async function load() {
 			await router.push(redirectTo)
 		}
 	} catch (e: unknown) {
-		error.value = String(e)
+		if (e instanceof NoApiUrlProvidedError) {
+			error.value = ERROR_NO_API_URL
+			return
+		}
+		if (e instanceof InvalidApiUrlProvidedError) {
+			error.value = t('apiConfig.error')
+			return
+		}
+		error.value = String(e.message)
 	}
 }
 

src/helpers/checkAndSetApiUrl.ts

@@ -4,8 +4,27 @@ const API_DEFAULT_PORT = '3456'
 
 export const ERROR_NO_API_URL = 'noApiUrlProvided'
 
+export class NoApiUrlProvidedError extends Error {
+	constructor() {
+		super()
+		this.message = 'No API URL provided'
+		this.name = 'NoApiUrlProvidedError'
+	}
+}
+
+export class InvalidApiUrlProvidedError extends Error {
+	constructor() {
+		super()
+		this.message = 'The provided API URL is invalid.'
+		this.name = 'InvalidApiUrlProvidedError'
+	}
+}
+
+export const checkAndSetApiUrl = (url: string | undefined | null): Promise<string> => {
+	if (url === '' || url === null || typeof url === 'undefined') {
+		throw new NoApiUrlProvidedError()
+	}
 
-export const checkAndSetApiUrl = (url: string): Promise<string> => {
 	if (url.startsWith('/')) {
 		url = window.location.host + url
 	}
@@ -17,8 +36,14 @@ export const checkAndSetApiUrl = (url: string): Promise<string> => {
 	) {
 		url = `${window.location.protocol}//${url}`
 	}
+	
+	let urlToCheck: URL
+	try {
+		urlToCheck = new URL(url)
+	} catch (e) {
+		throw new InvalidApiUrlProvidedError()
+	}
 
-	const urlToCheck: URL = new URL(url)
 	const origUrlToCheck = urlToCheck
 
 	const oldUrl = window.API_URL
@@ -86,6 +111,6 @@ export const checkAndSetApiUrl = (url: string): Promise<string> => {
 				return window.API_URL
 			}
 
-			throw new Error(ERROR_NO_API_URL)
+			throw new InvalidApiUrlProvidedError()
 		})
 }

src/i18n/lang/en.json

@@ -916,7 +916,7 @@
     "urlPlaceholder": "eg. https://localhost:3456",
     "change": "change",
     "use": "Using Vikunja installation at {0}",
-    "error": "Could not find or use Vikunja installation at \"{domain}\". Please try a different url.",
+    "error": "Could not find or use Vikunja installation at \"{domain}\". Please check if the url has the correct format and you can reach it when accessing it directly and try again.",
     "success": "Using Vikunja installation at \"{domain}\".",
     "urlRequired": "A url is required."
   },