@loopback/docs

--- lang: en title: 'API docs: core.lifecycleobserverregistry' keywords: LoopBack 4.0, LoopBack 4, Node.js, TypeScript, OpenAPI sidebar: lb4_sidebar editurl: https://github.com/loopbackio/loopback-next/tree/master/packages/core permalink: /doc/en/lb4/apidocs.core.lifecycleobserverregistry.html ---  [Home](./index.md) > [@loopback/core](./core.md) > [LifeCycleObserverRegistry](./core.lifecycleobserverregistry.md) ## LifeCycleObserverRegistry class A context-based registry for life cycle observers **Signature:** ```typescript export declare class LifeCycleObserverRegistry implements LifeCycleObserver ``` **Implements:** [LifeCycleObserver](./core.lifecycleobserver.md) ## Constructors <table><thead><tr><th> Constructor </th><th> Modifiers </th><th> Description </th></tr></thead> <tbody><tr><td markdown="1"> [(constructor)(context, observersView, options)](./core.lifecycleobserverregistry._constructor_.md) </td><td markdown="1"> </td><td markdown="1"> Constructs a new instance of the `LifeCycleObserverRegistry` class </td></tr> </tbody></table> ## Properties <table><thead><tr><th> Property </th><th> Modifiers </th><th> Type </th><th> Description </th></tr></thead> <tbody><tr><td markdown="1"> [context](./core.lifecycleobserverregistry.context.md) </td><td markdown="1"> `protected` `readonly` </td><td markdown="1"> [Context](./context.context.md) </td><td markdown="1"> </td></tr> <tr><td markdown="1"> [observersView](./core.lifecycleobserverregistry.observersview.md) </td><td markdown="1"> `protected` `readonly` </td><td markdown="1"> [ContextView](./context.contextview.md)<[LifeCycleObserver](./core.lifecycleobserver.md)> </td><td markdown="1"> </td></tr> <tr><td markdown="1"> [options](./core.lifecycleobserverregistry.options.md) </td><td markdown="1"> `protected` `readonly` </td><td markdown="1"> [LifeCycleObserverOptions](./core.lifecycleobserveroptions.md) </td><td markdown="1"> </td></tr> </tbody></table> ## Methods <table><thead><tr><th> Method </th><th> Modifiers </th><th> Description </th></tr></thead> <tbody><tr><td markdown="1"> [getObserverGroup(binding)](./core.lifecycleobserverregistry.getobservergroup.md) </td><td markdown="1"> `protected` </td><td markdown="1"> Get the group for a given life cycle observer binding </td></tr> <tr><td markdown="1"> [getObserverGroupsByOrder()](./core.lifecycleobserverregistry.getobservergroupsbyorder.md) </td><td markdown="1"> </td><td markdown="1"> Get observer groups ordered by the group </td></tr> <tr><td markdown="1"> [init()](./core.lifecycleobserverregistry.init.md) </td><td markdown="1"> </td><td markdown="1"> Notify all life cycle observers by group of `init` </td></tr> <tr><td markdown="1"> [invokeObserver(observer, event)](./core.lifecycleobserverregistry.invokeobserver.md) </td><td markdown="1"> `protected` </td><td markdown="1"> Invoke an observer for the given event </td></tr> <tr><td markdown="1"> [notifyGroups(events, groups, reverse)](./core.lifecycleobserverregistry.notifygroups.md) </td><td markdown="1"> `protected` </td><td markdown="1"> Emit events to the observer groups </td></tr> <tr><td markdown="1"> [notifyObservers(observers, bindings, event)](./core.lifecycleobserverregistry.notifyobservers.md) </td><td markdown="1"> `protected` </td><td markdown="1"> Notify an observer group of the given event </td></tr> <tr><td markdown="1"> [setOrderedGroups(groups)](./core.lifecycleobserverregistry.setorderedgroups.md) </td><td markdown="1"> </td><td markdown="1"> </td></tr> <tr><td markdown="1"> [sortObserverBindingsByGroup(bindings)](./core.lifecycleobserverregistry.sortobserverbindingsbygroup.md) </td><td markdown="1"> `protected` </td><td markdown="1"> Sort the life cycle observer bindings so that we can start/stop them in the right order. By default, we can start other observers before servers and stop them in the reverse order </td></tr> <tr><td markdown="1"> [start()](./core.lifecycleobserverregistry.start.md) </td><td markdown="1"> </td><td markdown="1"> Notify all life cycle observers by group of `start` </td></tr> <tr><td markdown="1"> [stop()](./core.lifecycleobserverregistry.stop.md) </td><td markdown="1"> </td><td markdown="1"> Notify all life cycle observers by group of `stop` </td></tr> </tbody></table>