github.com/dubbogo/gost@v1.14.0/gof/observer/event_listener.go (about)

     1  /*
     2   * Licensed to the Apache Software Foundation (ASF) under one or more
     3   * contributor license agreements.  See the NOTICE file distributed with
     4   * this work for additional information regarding copyright ownership.
     5   * The ASF licenses this file to You under the Apache License, Version 2.0
     6   * (the "License"); you may not use this file except in compliance with
     7   * the License.  You may obtain a copy of the License at
     8   *
     9   *     http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the License for the specific language governing permissions and
    15   * limitations under the License.
    16   */
    17  
    18  package observer
    19  
    20  import (
    21  	"reflect"
    22  )
    23  
    24  import (
    25  	gxsort "github.com/dubbogo/gost/sort"
    26  )
    27  
    28  // EventListener is an new interface used to align with dubbo 2.7.5
    29  // It contains the Prioritized means that the listener has its priority
    30  // Usually the priority of your custom implementation should be between [100, 9000]
    31  // the number outside the range will be though as system reserve number
    32  // usually implementation should be singleton
    33  type EventListener interface {
    34  	gxsort.Prioritizer
    35  	// OnEvent handle this event
    36  	OnEvent(e Event) error
    37  	// GetEventType listen which event type
    38  	GetEventType() reflect.Type
    39  }
    40  
    41  // ConditionalEventListener only handle the event which it can handle
    42  type ConditionalEventListener interface {
    43  	EventListener
    44  	// Accept will make the decision whether it should handle this event
    45  	Accept(e Event) bool
    46  }
    47  
    48  type ChangedNotify interface {
    49  	Notify(e Event)
    50  }