@loopback/context - npm Package Compare versions

Comparing version 3.1.0 to 3.2.0

CHANGELOG.md

@@ -6,2 +6,14 @@ # Change Log
 
+# [3.2.0](https://github.com/strongloop/loopback-next/compare/@loopback/context@3.1.0...@loopback/context@3.2.0) (2020-03-24)
+
+
+### Features
+
+* **context:** emit bind/unbind events on ContextView ([65e3d38](https://github.com/strongloop/loopback-next/commit/65e3d38a34b351929ba422de667bc236e9619ebe))
+* **context:** improve context view for bind/unbind events ([6a5f90a](https://github.com/strongloop/loopback-next/commit/6a5f90aadb5f5ba213f2da7ea7843f488a09f95d))
+
+
+
+
+
 # [3.1.0](https://github.com/strongloop/loopback-next/compare/@loopback/context@3.0.0...@loopback/context@3.1.0) (2020-03-17)
@@ -8,0 +20,0 @@

dist/context-view.d.ts

@@ -7,2 +7,3 @@ /// <reference types="node" />
 import { Context } from './context';
+import { ContextEvent } from './context-event';
 import { ContextEventType, ContextObserver } from './context-observer';
@@ -14,2 +15,11 @@ import { Subscription } from './context-subscription';
 /**
+ * An event emitted by a `ContextView`
+ */
+export interface ContextViewEvent<T> extends ContextEvent {
+    /**
+     * Optional cached value for an `unbind` event
+     */
+    cachedValue?: T;
+}
+/**
  * `ContextView` provides a view for a given context chain to maintain a live
@@ -24,2 +34,4 @@ * list of matching bindings and their resolved values within the context
  * `ContextView` is an event emitter that emits the following events:
+ * - 'bind': when a binding is added to the view
+ * - 'unbind': when a binding is removed from the view
  * - 'close': when the view is closed (stopped observing context events)
@@ -30,10 +42,31 @@ * - 'refresh': when the view is refreshed as bindings are added/removed
 export declare class ContextView<T = unknown> extends EventEmitter implements ContextObserver {
-    protected readonly context: Context;
+    readonly context: Context;
     readonly filter: BindingFilter;
     readonly comparator?: BindingComparator | undefined;
+    /**
+     * An array of cached bindings that matches the binding filter
+     */
     protected _cachedBindings: Readonly<Binding<T>>[] | undefined;
-    protected _cachedValues: T[] | undefined;
+    /**
+     * A map of cached values by binding
+     */
+    protected _cachedValues: Map<Readonly<Binding<T>>, T> | undefined;
     private _subscription;
+    /**
+     * Create a context view
+     * @param context - Context object to watch
+     * @param filter - Binding filter to match bindings of interest
+     * @param comparator - Comparator to sort the matched bindings
+     */
     constructor(context: Context, filter: BindingFilter, comparator?: BindingComparator | undefined);
     /**
+     * Update the cached values keyed by binding
+     * @param values - An array of resolved values
+     */
+    private updateCachedValues;
+    /**
+     * Get an array of cached values
+     */
+    private getCachedValues;
+    /**
      * Start listening events from the context
@@ -58,3 +91,3 @@ */
      */
-    observe(event: ContextEventType, binding: Readonly<Binding<unknown>>): void;
+    observe(event: ContextEventType, binding: Readonly<Binding<unknown>>, context: Context): void;
     /**
@@ -61,0 +94,0 @@ * Refresh the view by invalidating its cache

dist/context-view.js

@@ -25,2 +25,4 @@ "use strict";
  * `ContextView` is an event emitter that emits the following events:
+ * - 'bind': when a binding is added to the view
+ * - 'unbind': when a binding is removed from the view
  * - 'close': when the view is closed (stopped observing context events)
@@ -31,2 +33,8 @@ * - 'refresh': when the view is refreshed as bindings are added/removed
 class ContextView extends events_1.EventEmitter {
+    /**
+     * Create a context view
+     * @param context - Context object to watch
+     * @param filter - Binding filter to match bindings of interest
+     * @param comparator - Comparator to sort the matched bindings
+     */
     constructor(context, filter, comparator) {
@@ -39,2 +47,23 @@ super();
     /**
+     * Update the cached values keyed by binding
+     * @param values - An array of resolved values
+     */
+    updateCachedValues(values) {
+        var _a;
+        if (this._cachedBindings == null)
+            return undefined;
+        this._cachedValues = new Map();
+        for (let i = 0; i < ((_a = this._cachedBindings) === null || _a === void 0 ? void 0 : _a.length); i++) {
+            this._cachedValues.set(this._cachedBindings[i], values[i]);
+        }
+        return this._cachedValues;
+    }
+    /**
+     * Get an array of cached values
+     */
+    getCachedValues() {
+        var _a, _b;
+        return Array.from((_b = (_a = this._cachedValues) === null || _a === void 0 ? void 0 : _a.values()) !== null && _b !== void 0 ? _b : []);
+    }
+    /**
      * Start listening events from the context
@@ -81,3 +110,6 @@ */
         }
-        this._cachedBindings = found;
+        /* istanbul ignore if */
+        if (debug.enabled) {
+            debug('Bindings found', found.map(b => b.key));
+        }
         return found;
@@ -88,3 +120,17 @@ }
      */
-    observe(event, binding) {
+    observe(event, binding, context) {
+        var _a;
+        const ctxEvent = {
+            context,
+            binding,
+            type: event,
+        };
+        debug('Observed event %s %s %s', event, binding.key, context.name);
+        if (event === 'unbind') {
+            const cachedValue = (_a = this._cachedValues) === null || _a === void 0 ? void 0 : _a.get(binding);
+            this.emit(event, Object.assign(Object.assign({}, ctxEvent), { cachedValue }));
+        }
+        else {
+            this.emit(event, ctxEvent);
+        }
         this.refresh();
@@ -107,5 +153,7 @@ }
         debug('Resolving values');
-        if (this._cachedValues != null)
-            return this._cachedValues;
-        let result = value_promise_1.resolveList(this.bindings, b => {
+        if (this._cachedValues != null) {
+            return this.getCachedValues();
+        }
+        const bindings = this.bindings;
+        let result = value_promise_1.resolveList(bindings, b => {
             return b.getValue(this.context, resolution_session_1.ResolutionSession.fork(session));
@@ -115,3 +163,3 @@ });
             result = result.then(values => {
-                this._cachedValues = values;
+                this.updateCachedValues(values);
                 this.emit('resolve', values);
@@ -122,3 +170,4 @@ return values;
         else {
-            this._cachedValues = result;
+            // Clone the array so that the cached values won't be mutated
+            this.updateCachedValues(result);
             this.emit('resolve', result);
@@ -137,5 +186,5 @@ }
         if (this._cachedValues == null) {
-            this._cachedValues = await this.resolve(session);
+            return this.resolve(session);
         }
-        return this._cachedValues;
+        return this.getCachedValues();
     }
@@ -142,0 +191,0 @@ /**

package.json

 {
   "name": "@loopback/context",
-  "version": "3.1.0",
+  "version": "3.2.0",
   "description": "LoopBack's container for Inversion of Control",
@@ -21,3 +21,3 @@ "engines": {
   "dependencies": {
-    "@loopback/metadata": "^2.0.1",
+    "@loopback/metadata": "^2.0.2",
     "debug": "^4.1.1",
@@ -29,9 +29,9 @@ "p-event": "^4.1.0",
   "devDependencies": {
-    "@loopback/build": "^4.0.1",
-    "@loopback/eslint-config": "^6.0.1",
-    "@loopback/testlab": "^2.0.1",
+    "@loopback/build": "^5.0.0",
+    "@loopback/eslint-config": "^6.0.2",
+    "@loopback/testlab": "^2.0.2",
     "@types/bluebird": "^3.5.30",
     "@types/debug": "^4.1.5",
     "@types/node": "^10.17.17",
-    "@types/uuid": "^7.0.0",
+    "@types/uuid": "^7.0.2",
     "bluebird": "^3.7.2"
@@ -61,3 +61,3 @@ },
   },
-  "gitHead": "85a906121febac2dbd2d4adcdc21b5939a770951"
+  "gitHead": "020ed59b8bed8b38e1e4cede06a22b234effdb57"
 }

src/context-view.ts

@@ -13,2 +13,3 @@ // Copyright IBM Corp. 2019,2020. All Rights Reserved.
 import {Context} from './context';
+import {ContextEvent} from './context-event';
 import {ContextEventType, ContextObserver} from './context-observer';
@@ -23,2 +24,12 @@ import {Subscription} from './context-subscription';
 /**
+ * An event emitted by a `ContextView`
+ */
+export interface ContextViewEvent<T> extends ContextEvent {
+  /**
+   * Optional cached value for an `unbind` event
+   */
+  cachedValue?: T;
+}
+
+/**
  * `ContextView` provides a view for a given context chain to maintain a live
@@ -33,2 +44,4 @@ * list of matching bindings and their resolved values within the context
  * `ContextView` is an event emitter that emits the following events:
+ * - 'bind': when a binding is added to the view
+ * - 'unbind': when a binding is removed from the view
  * - 'close': when the view is closed (stopped observing context events)
@@ -40,8 +53,20 @@ * - 'refresh': when the view is refreshed as bindings are added/removed
   implements ContextObserver {
+  /**
+   * An array of cached bindings that matches the binding filter
+   */
   protected _cachedBindings: Readonly<Binding<T>>[] | undefined;
-  protected _cachedValues: T[] | undefined;
+  /**
+   * A map of cached values by binding
+   */
+  protected _cachedValues: Map<Readonly<Binding<T>>, T> | undefined;
   private _subscription: Subscription | undefined;
 
+  /**
+   * Create a context view
+   * @param context - Context object to watch
+   * @param filter - Binding filter to match bindings of interest
+   * @param comparator - Comparator to sort the matched bindings
+   */
   constructor(
-    protected readonly context: Context,
+    public readonly context: Context,
     public readonly filter: BindingFilter,
@@ -54,2 +79,22 @@ public readonly comparator?: BindingComparator,
   /**
+   * Update the cached values keyed by binding
+   * @param values - An array of resolved values
+   */
+  private updateCachedValues(values: T[]) {
+    if (this._cachedBindings == null) return undefined;
+    this._cachedValues = new Map();
+    for (let i = 0; i < this._cachedBindings?.length; i++) {
+      this._cachedValues.set(this._cachedBindings[i], values[i]);
+    }
+    return this._cachedValues;
+  }
+
+  /**
+   * Get an array of cached values
+   */
+  private getCachedValues() {
+    return Array.from(this._cachedValues?.values() ?? []);
+  }
+
+  /**
    * Start listening events from the context
@@ -98,3 +143,9 @@ */
     }
-    this._cachedBindings = found;
+    /* istanbul ignore if */
+    if (debug.enabled) {
+      debug(
+        'Bindings found',
+        found.map(b => b.key),
+      );
+    }
     return found;
@@ -106,3 +157,23 @@ }
    */
-  observe(event: ContextEventType, binding: Readonly<Binding<unknown>>) {
+  observe(
+    event: ContextEventType,
+    binding: Readonly<Binding<unknown>>,
+    context: Context,
+  ) {
+    const ctxEvent: ContextViewEvent<T> = {
+      context,
+      binding,
+      type: event,
+    };
+    debug('Observed event %s %s %s', event, binding.key, context.name);
+
+    if (event === 'unbind') {
+      const cachedValue = this._cachedValues?.get(
+        binding as Readonly<Binding<T>>,
+      );
+      this.emit(event, {...ctxEvent, cachedValue});
+    } else {
+      this.emit(event, ctxEvent);
+    }
+
     this.refresh();
@@ -127,4 +198,7 @@ }
     debug('Resolving values');
-    if (this._cachedValues != null) return this._cachedValues;
-    let result = resolveList(this.bindings, b => {
+    if (this._cachedValues != null) {
+      return this.getCachedValues();
+    }
+    const bindings = this.bindings;
+    let result = resolveList(bindings, b => {
       return b.getValue(this.context, ResolutionSession.fork(session));
@@ -134,3 +208,3 @@ });
       result = result.then(values => {
-        this._cachedValues = values;
+        this.updateCachedValues(values);
         this.emit('resolve', values);
@@ -140,3 +214,4 @@ return values;
     } else {
-      this._cachedValues = result;
+      // Clone the array so that the cached values won't be mutated
+      this.updateCachedValues(result);
       this.emit('resolve', result);
@@ -156,5 +231,5 @@ }
     if (this._cachedValues == null) {
-      this._cachedValues = await this.resolve(session);
+      return this.resolve(session);
     }
-    return this._cachedValues;
+    return this.getCachedValues();
   }
@@ -161,0 +236,0 @@

New alerts

License Policy Violation

License

This package is not allowed per your license policy. Review the package's license to ensure compliance.

Found 1 instance in 1 package

Fixed alerts

License Policy Violation

License

This package is not allowed per your license policy. Review the package's license to ensure compliance.

Found 1 instance in 1 package

Improved metrics

Total package byte prevSize

613910

increased by1.03%

Lines of code

13546

increased by1.13%

Dependency changes

• Updated@loopback/metadata@^2.0.2