storage
Local Storage
Persistent key-value storage on device
Overview
Native storage that persists across sessions
Store data locally on the device using native SharedPreferences. Data persists even after app restart, unlike WebView localStorage which can be cleared.
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More Reliable Than localStorage
Native storage is more persistent than browser localStorage which can be cleared by the system.
setItem()
Save data
shift2appjs.setItem(key, value)
Stores a value with the specified key. Values are stored as strings.
Parameters
key
String - Unique identifier for the data
value
String - Data to store (use JSON.stringify for objects)
Returns
void
// Store simple value
shift2appjs.setItem("username", "john_doe");
// Store object
const user = { id: 123, name: "John", email: "john@example.com" };
shift2appjs.setItem("user_data", JSON.stringify(user));
// Store settings
shift2appjs.setItem("dark_mode", "true");
shift2appjs.setItem("notification_enabled", "true");getItem()
Retrieve data
shift2appjs.getItem(key)
Retrieves the value stored with the specified key.
Parameters
key
String - Key to look up
Returns
String - The stored value, or empty string if not found
// Get simple value
const username = shift2appjs.getItem("username");
// Get and parse object
const userData = shift2appjs.getItem("user_data");
if (userData) {
const user = JSON.parse(userData);
console.log("Welcome back,", user.name);
}
// Check boolean setting
const darkMode = shift2appjs.getItem("dark_mode") === "true";
if (darkMode) {
document.body.classList.add("dark");
}removeItem()
Delete data
shift2appjs.removeItem(key)
Removes the value stored with the specified key.
Parameters
key
String - Key to remove
Returns
void
// Remove on logout
function logout() {
shift2appjs.removeItem("user_data");
shift2appjs.removeItem("auth_token");
window.location.href = "/login";
}shift2appjs.clearStorage()
Removes all stored data.
Returns
void
// Clear all data
function resetApp() {
if (confirm("This will clear all your data. Continue?")) {
shift2appjs.clearStorage();
window.location.reload();
}
}getAllKeys()
List all stored keys
shift2appjs.getAllKeys()
Returns an array of all stored keys.
Returns
String - JSON array of keys
// List all keys
const keys = JSON.parse(shift2appjs.getAllKeys());
console.log("Stored keys:", keys);
// Example output: ["username", "user_data", "dark_mode"]Complete Example: User Preferences
// Preferences manager
const Preferences = {
get(key, defaultValue = null) {
if (typeof shift2appjs === "undefined") {
return localStorage.getItem(key) || defaultValue;
}
const value = shift2appjs.getItem(key);
return value || defaultValue;
},
set(key, value) {
if (typeof shift2appjs === "undefined") {
localStorage.setItem(key, value);
} else {
shift2appjs.setItem(key, value);
}
},
getObject(key, defaultValue = {}) {
const json = this.get(key);
try {
return json ? JSON.parse(json) : defaultValue;
} catch {
return defaultValue;
}
},
setObject(key, value) {
this.set(key, JSON.stringify(value));
}
};
// Usage
Preferences.set("theme", "dark");
Preferences.setObject("user", { id: 1, name: "John" });
const theme = Preferences.get("theme", "light");
const user = Preferences.getObject("user");