RSX_STORAGE(1)                    RSpade Manual                    RSX_STORAGE(1)

NAME
    Rsx_Storage - Scoped browser storage helper with automatic fallback

SYNOPSIS
    // Session storage (cleared on tab close)
    Rsx_Storage.session_set(key, value)
    Rsx_Storage.session_get(key)
    Rsx_Storage.session_remove(key)

    // Local storage (persists across sessions)
    Rsx_Storage.local_set(key, value)
    Rsx_Storage.local_get(key)
    Rsx_Storage.local_remove(key)

DESCRIPTION
    Rsx_Storage provides safe, scoped access to browser sessionStorage and
    localStorage with automatic handling of unavailable storage, quota exceeded
    errors, and scope invalidation.

    Key features:
    - Automatic scoping by session, user, site, and build version
    - Graceful degradation when storage unavailable (returns null)
    - Automatic quota management (clears and retries when full)
    - Scope validation (clears stale data on scope change)
    - Developer-friendly key format for easy inspection

SCOPING SYSTEM
    All storage keys are automatically scoped to prevent data leakage between:
    - Different sessions (window.rsxapp.session_hash - hashed, non-reversible)
    - Different users (window.rsxapp.user.id)
    - Different sites (window.rsxapp.site.id)
    - Different builds (window.rsxapp.build_key)

    The scope is calculated by combining these values into a suffix:
        session_hash_user_id_site_id_build_key

    This scope is stored in the special key `_rsx_scope_key`. On page load, if
    this key doesn't exist or doesn't match the current scope, all RSpade keys
    are cleared and the new scope is stored.

    The session_hash is a server-generated HMAC hash of the session cookie using
    the application's encryption key, making it non-reversible while maintaining
    consistency per session.

    Example scope suffix:
        a1b2c3d4e5f6_42_1_v2.1.0
        └─ session ──┘ │  │ └─ build
                      user │
                          site

KEY FORMAT
    Keys are stored with an `rsx::` namespace prefix, followed by the developer
    key, followed by the scope suffix:

        rsx::developer_key::scope_suffix

    Example:
        rsx::flash_queue::abc123def456_42_1_v2.1.0

    The `rsx::` prefix serves two purposes:
    1. Identifies RSpade keys for safe selective clearing (scope changes, quota)
    2. Prevents collisions with other JavaScript libraries

    This format allows developers to easily identify keys in browser developer
    tools while maintaining proper scoping and coexistence with third-party
    libraries. When inspecting storage, you'll see the `rsx::` prefix, your
    original key name, and the scope suffix.

STORAGE AVAILABILITY
    Rsx_Storage automatically detects if sessionStorage or localStorage are
    available. Storage may be unavailable due to:

    - Private browsing mode (some browsers block storage)
    - Browser security settings
    - Storage quota set to 0
    - Browser bugs or incompatibilities

    When storage is unavailable:
    - set() operations are silently ignored (no error)
    - get() operations return null
    - remove() operations are silently ignored

    This allows the application to continue functioning even when storage is
    unavailable, as long as the stored data is non-critical.

SIZE LIMIT
    Individual values larger than 1 MB are automatically rejected and not stored.

    When attempting to store data > 1 MB:
    - Operation is silently skipped (no error thrown)
    - Console warning logged with actual size
    - get() will return null for that key

    This prevents quota issues and ensures browser storage remains performant.
    If you need to store large data, consider:
    - Storing server-side in database
    - Using IndexedDB for large client-side data
    - Splitting data into smaller chunks

QUOTA EXCEEDED HANDLING
    When a set() operation fails due to quota exceeded (storage full), Rsx_Storage
    automatically:

    1. Clears only RSpade keys (keys starting with `rsx::`)
    2. Preserves other libraries' data
    3. Restores the _rsx_scope_key
    4. Retries the set() operation once

    If the retry also fails, the error is logged and the operation is abandoned.

    This ensures the application continues functioning even when storage is full,
    and minimizes impact on other JavaScript libraries sharing the same storage.
    Only RSpade's previously stored data will be lost.

SCOPE INVALIDATION
    Storage is automatically validated before every write operation. When the scope
    changes, only RSpade keys (starting with `rsx::`) are cleared, preserving other
    libraries' data.

    Scope changes occur when:

    - User logs in/out (user ID changes)
    - User switches sites (site ID changes)
    - Application is updated (build key changes)
    - Session changes (rsx cookie changes)

    This prevents stale data from one context bleeding into another context.

    Example: User A logs in, stores preferences, logs out. User B logs in on the
    same browser. User B sees clean RSpade storage, not User A's data. Other
    libraries' data (e.g., analytics cookies, third-party preferences) remains
    intact.

VOLATILE STORAGE WARNING
    Browser storage is VOLATILE and can be cleared at any time. Never store data
    critical to application functionality.

    Storage can be lost due to:
    - User clearing browser data
    - Private browsing mode restrictions
    - Quota exceeded errors (automatic clear + retry)
    - Scope changes (logout, build update, session change)
    - Browser storage unavailable
    - Storage corruption or browser bugs

    ONLY store data that is:
    - Cached for performance (can be re-fetched)
    - UI convenience state (non-essential)
    - Transient messages (flash alerts, notifications)

    If data is REQUIRED for the application to function correctly, store it
    server-side in the database or PHP session.

EXAMPLES
    Cache API response data (sessionStorage)
        // Store cached data
        const users = await fetch_users();
        Rsx_Storage.session_set('cached_users', users);

        // Retrieve cached data
        let users = Rsx_Storage.session_get('cached_users');
        if (!users) {
            users = await fetch_users();
            Rsx_Storage.session_set('cached_users', users);
        }

    Persist UI preferences (localStorage)
        // Save theme preference
        Rsx_Storage.local_set('theme', 'dark');

        // Load theme preference
        const theme = Rsx_Storage.local_get('theme') || 'light';
        apply_theme(theme);

    Store flash alert queue (sessionStorage)
        // Queue persists across page navigation
        Rsx_Storage.session_set('flash_queue', messages);

        // Restore queue on next page
        const messages = Rsx_Storage.session_get('flash_queue') || [];

    Complex data structures
        // Automatically JSON serialized
        Rsx_Storage.local_set('user_prefs', {
            theme: 'dark',
            sidebar_collapsed: true,
            recent_items: [1, 2, 3]
        });

        // Automatically JSON parsed
        const prefs = Rsx_Storage.local_get('user_prefs');
        console.log(prefs.theme); // 'dark'

    Handling unavailable storage
        // Always check for null (storage unavailable or key not found)
        const cached = Rsx_Storage.session_get('data');
        if (cached) {
            use_cached_data(cached);
        } else {
            fetch_fresh_data();
        }

    Removing stale data
        // Clean up when no longer needed
        Rsx_Storage.session_remove('temp_data');

SESSIONSTORAGE VS LOCALSTORAGE
    sessionStorage:
    - Cleared when tab/window closes
    - Not shared across tabs/windows
    - Use for: temporary data, current session state, flash messages

    localStorage:
    - Persists across browser sessions
    - Shared across all tabs/windows of same origin
    - Use for: user preferences, cached data, long-term UI state

    Both are scoped identically by Rsx_Storage (cookie, user, site, build).

MIGRATION FROM NATIVE STORAGE
    If you're currently using sessionStorage/localStorage directly:

    Before:
        sessionStorage.setItem('my_key', JSON.stringify(data));
        const data = JSON.parse(sessionStorage.getItem('my_key'));
        sessionStorage.removeItem('my_key');

    After:
        Rsx_Storage.session_set('my_key', data);
        const data = Rsx_Storage.session_get('my_key');
        Rsx_Storage.session_remove('my_key');

    Benefits:
    - No manual JSON.stringify/parse
    - Automatic scoping (prevents data leakage)
    - Graceful handling of unavailable storage
    - Automatic quota management
    - Scope validation

DEBUGGING
    Inspect storage in browser developer tools:

    1. Open Developer Tools (F12)
    2. Navigate to Application tab (Chrome) or Storage tab (Firefox)
    3. Expand Session Storage or Local Storage
    4. Look for keys matching: rsx::your_key::scope_suffix

    The _rsx_scope_key shows the current active scope.
    All RSpade keys are prefixed with `rsx::` for easy identification.

    Console logging:
    - Scope changes: "[Rsx_Storage] Scope changed, clearing RSpade keys only"
    - First use: "[Rsx_Storage] Initializing scope (first use)"
    - Quota exceeded: "[Rsx_Storage] Quota exceeded, clearing RSpade keys"
    - Keys cleared: "[Rsx_Storage] Cleared X RSpade keys"
    - Errors: "[Rsx_Storage] Failed to..."

FILE LOCATION
    /system/app/RSpade/Core/Js/Rsx_Storage.js

SEE ALSO
    Flash Alert system (uses Rsx_Storage for queue persistence)
    php artisan rsx:man flash_alert

RSPADE                           January 2025                    RSX_STORAGE(1)