feat: Custom handling for Feathers events

Closes #221

This adds the `handleEvents` properties, which let you fine-tune the event handling process per event.

```js
handleEvents: {
  created(item, { model, models }) {
    return true // truthy adds the record
  },
  patched(item, { model, models }) {
    return true // truthy adds the record
  },
  updated(item, { model, models }) {
    return true // truthy adds the record
  },
  removed(item, { model, models }) {
    return true // truthy removes the record from the store
  },
}
```

Thanks to @barata for the great idea!

Author: marshallswain

src/service-module/make-service-plugin.ts

@@ -3,7 +3,11 @@ eslint
 @typescript-eslint/explicit-function-return-type: 0,
 @typescript-eslint/no-explicit-any: 0
 */
-import { FeathersVuexOptions, MakeServicePluginOptions } from './types'
+import {
+  FeathersVuexOptions,
+  MakeServicePluginOptions,
+  HandleEvents
+} from './types'
 import makeServiceModule from './make-service-module'
 import { globalModels, prepareAddModel } from './global-models'
 import { makeNamespace, getServicePath, assignIfNotPresent } from '../utils'
@@ -13,13 +17,15 @@ const defaults = {
   namespace: '', // The namespace for the Vuex module. Will generally be derived from the service.path, service.name, when available. Otherwise, it must be provided here, explicitly.
   nameStyle: 'short', // Determines the source of the module name. 'short', 'path', or 'explicit'
   servicePath: '',
+  handleEvents: {} as HandleEvents,
   state: {}, // for custom state
   getters: {}, // for custom getters
   mutations: {}, // for custom mutations
   actions: {}, // for custom actions
   instanceDefaults: () => ({}), // Default instanceDefaults returns an empty object
   setupInstance: instance => instance // Default setupInstance returns the instance
 }
+const events = ['created', 'patched', 'updated', 'removed']
 
 /**
  * prepare only wraps the makeServicePlugin to provide the globalOptions.
@@ -36,6 +42,12 @@ export default function prepareMakeServicePlugin(
    * (3) Setup real-time events
    */
   return function makeServicePlugin(config: MakeServicePluginOptions) {
+    // Setup the event handlers. By default they just return the value of `options.enableEvents`
+    defaults.handleEvents = events.reduce((obj, eventName) => {
+      obj[eventName] = () => config.enableEvents || true
+      return obj
+    }, {} as HandleEvents)
+
     const options = Object.assign({}, defaults, globalOptions, config)
     const {
       Model,
@@ -93,30 +105,31 @@ export default function prepareMakeServicePlugin(
 
       // (3^) Setup real-time events
       if (options.enableEvents) {
+        const handleEvent = (eventName, item, mutationName) => {
+          const affectsStore = options.handleEvents[eventName](item, {
+            model: Model,
+            models: globalModels
+          })
+          affectsStore &&
+            store.dispatch(`${options.namespace}/${mutationName}`, item)
+        }
+
         // Listen to socket events when available.
         service.on('created', item => {
-          store.dispatch(`${options.namespace}/addOrUpdate`, item)
-          if (Model.emit) {
-            Model.emit('created', item)
-          }
+          handleEvent('created', item, 'addOrUpdate')
+          Model.emit && Model.emit('created', item)
         })
         service.on('updated', item => {
-          store.dispatch(`${options.namespace}/addOrUpdate`, item)
-          if (Model.emit) {
-            Model.emit('updated', item)
-          }
+          handleEvent('updated', item, 'addOrUpdate')
+          Model.emit && Model.emit('updated', item)
         })
         service.on('patched', item => {
-          store.dispatch(`${options.namespace}/addOrUpdate`, item)
-          if (Model.emit) {
-            Model.emit('patched', item)
-          }
+          handleEvent('patched', item, 'addOrUpdate')
+          Model.emit && Model.emit('patched', item)
         })
         service.on('removed', item => {
-          store.commit(`${options.namespace}/removeItem`, item)
-          if (Model.emit) {
-            Model.emit('removed', item)
-          }
+          handleEvent('removed', item, 'removeItem')
+          Model.emit && Model.emit('removed', item)
         })
       }
     }

src/service-module/service-module.state.ts

@@ -11,6 +11,7 @@ export default function makeDefaultState(servicePath, options) {
     'actions',
     'getters',
     'instanceDefaults',
+    'handleEvents',
     'Model',
     'mutations',
     'service',

src/service-module/types.ts

@@ -8,6 +8,7 @@ export interface FeathersVuexOptions {
   autoRemove?: boolean
   debug?: boolean
   enableEvents?: boolean
+  handleEvents?: HandleEvents
   idField?: string
   tempIdField?: string
   keepCopiesInStore?: boolean
@@ -19,6 +20,13 @@ export interface FeathersVuexOptions {
   whitelist?: string[]
 }
 
+export interface HandleEvents {
+  created?: Function
+  patched?: Function
+  updated?: Function
+  removed?: Function
+}
+
 export interface MakeServicePluginOptions {
   Model: any
   service: any