Session and Instance Storage

The storage API provides mechanisms to persist key-value pairs either at the session scope (shared across all instances/tabs of a session) or the instance scope (isolated to the current browser tab/page). Both storage layers are thread-safe and allow concurrent access from multiple goroutines.

---

Session Storage

Session-scoped storage persists for the lifetime of a session and is shared across all browser tabs or instances belonging to that session.

SessionSave

Stores a key-value pair in session storage.

func SessionSave(ctx context.Context, key any, value any) any

• key: any type, identifier for the stored value.
  
• value: any type, value to persist.
  
• Returns the previous value under the key or nil

Example:

// Store user preferences globally across the session
type Preferences struct {
    Theme    string
    Language string
}

oldPrefs, ok := doors.SessionSave(ctx, "prefs", Preferences{
    Theme:    "dark",
    Language: "en",
}).(Preferences)

---

SessionLoad

Retrieves a value from session storage by its key.

func SessionLoad(ctx context.Context, key any) any

• Returns the stored value, or nil if no value exists.
  

Example:

// Load user preferences
prefs, ok := doors.SessionLoad(ctx, "prefs").(Preferences)
if !ok {
    return
}
applyTheme(prefs.Theme)

---

SessionRemove

Deletes a key-value pair from session storage.

func SessionRemove(ctx context.Context, key any) any

• If the key does not exist, no action is taken.
  
• Returns the removed value or nil.

Example:

// Remove user preferences
doors.SessionRemove(ctx, "prefs")

---

Instance Storage

Instance-scoped storage persists only for the lifetime of the current instance (a single browser tab or page). Each instance has its own isolated storage.

InstanceSave

Stores a key-value pair in instance storage.

func InstanceSave(ctx context.Context, key any, value any) any

• key: any type, identifier for the stored value.
  
• value: any type, value to persist.
  
• Returns previous value under the key or nil

Example:

// Store preferences only for this tab
type Preferences struct {
    Theme    string
    Language string
}

saved := doors.InstanceSave(ctx, "prefs", Preferences{
    Theme:    "dark",
    Language: "en",
})

---

InstanceLoad

Retrieves a value from instance storage by its key.

func InstanceLoad(ctx context.Context, key any) any

• Returns the stored value, or nil if the key does not exist.
  
• The result must be type-asserted to its original type.
  

Example:

// Load preferences specific to this tab
if prefs, ok := doors.InstanceLoad(ctx, "prefs").(Preferences); ok {
    applyTheme(prefs.Theme)
}

---

InstanceRemove

Deletes a key-value pair from instance storage.

func InstanceRemove(ctx context.Context, key any) any

• Returns the removed value or nil

Example:

// Remove preferences for this tab
doors.InstanceRemove(ctx, "prefs")

---

Notes

• Thread-safety: Both storage layers are safe for concurrent use across goroutines.
  
• Persistence:
  
  • Session storage persists for the session’s lifetime and synchronizes across all instances
  • Instance storage persists only for the current browser tab/page and is isolated from others.
    
• Type safety: Values retrieved must be explicitly type-asserted.