nsIWeakReference

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« XPCOM API Reference

Contents 1 Summary 2 Methods 3 Remarks 4 History 5 See also

[edit] Summary

The nsIWeakReference interface represents a proxy for an XPCOM object. It allows a consumer to hold an indirect, non-owning reference to an XPCOM object.

See Weak reference for a more detailed description.

#include "nsIWeakReference.h"

[scriptable, uuid=(9188bc85-f92e-11d2-81ef-0060083a0bcf)]
interface nsIWeakReference : nsISupports { ... };

[edit] Methods

QueryReferent

The QueryReferent method queries an interface on the referent if it exists, and like nsISupports::QueryInterface, produces an owning reference to the desired interface.

[edit] Remarks

An instance of nsIWeakReference is a proxy object that cooperates with its referent to give clients a non-owning, non-dangling reference. Clients own the nsIWeakReference instance. The QueryReferent method provides a (hopefully short-lived) owning reference on demand, through which clients can get useful access to the referent, while it still exists.

QueryReferent may fail if the referent no longer exists.

[edit] History

This interface was frozen for Mozilla 0.9.9. See bug 48726 for details.

[edit] See also

QueryReferent, nsISupports::QueryInterface, nsISupportsWeakReference