Migrate code to composition api.

src/composables/useApi.js

@@ -0,0 +1,36 @@
+import { getPreferenceBoolean, getPreferenceString } from "./usePreferences.js";
+
+export function fetchJson(url, params, options) {
+    if (params) {
+        url = new URL(url);
+        for (var param in params) url.searchParams.set(param, params[param]);
+    }
+    return fetch(url, options).then(response => {
+        return response.json();
+    });
+}
+
+export function hashCode(s) {
+    return s.split("").reduce(function (a, b) {
+        a = (a << 5) - a + b.charCodeAt(0);
+        return a & a;
+    }, 0);
+}
+
+export function apiUrl() {
+    return getPreferenceString("instance", import.meta.env.VITE_PIPED_API);
+}
+
+export function authApiUrl() {
+    if (getPreferenceBoolean("authInstance", false)) {
+        return getPreferenceString("auth_instance_url", apiUrl());
+    } else return apiUrl();
+}
+
+export function getAuthToken() {
+    return getPreferenceString("authToken" + hashCode(authApiUrl()));
+}
+
+export function isAuthenticated() {
+    return getAuthToken() !== undefined;
+}