Sync events

package.json

@@ -144,7 +144,7 @@
     "safe-stable-stringify": "^2.3.1",
     "secure-json-parse": "^2.4.0",
     "sorted-btree": "^1.8.1",
-    "thingies": "^1.11.1",
+    "thingies": "^1.14.1",
     "tinybench": "^2.4.0",
     "ts-jest": "^29.1.0",
     "ts-loader": "^9.4.3",

src/json-crdt/__demos__/getting-started.ts

@@ -10,7 +10,7 @@ import {Model, n} from '..';
 import {vec} from '../../json-crdt-patch';
 
 // Create a new JSON CRDT document, 1234 is the session ID.
-const model = Model.withLogicalClock(1234) as Model<
+const model = Model.withLogicalClock(1234) as any as Model<
   n.obj<{
     counter: n.val<n.con<number>>;
     text: n.str;

src/json-crdt/__demos__/type-safety.ts

@@ -10,7 +10,7 @@ import {Model, n} from '..';
 
 console.clear();
 
-const model = Model.withLogicalClock(1234) as Model<
+const model = Model.withLogicalClock(1234) as any as Model<
   n.obj<{
     num: n.con<number>;
     text: n.str;

src/json-crdt/codec/indexed/binary/Encoder.ts

@@ -15,7 +15,7 @@ export class Encoder {
     this.enc = new CborEncoder<CrdtWriter>(writer || new CrdtWriter());
   }
 
-  public encode(doc: Model, clockTable: ClockTable = ClockTable.from(doc.clock)): IndexedFields {
+  public encode(doc: Model<any>, clockTable: ClockTable = ClockTable.from(doc.clock)): IndexedFields {
     this.clockTable = clockTable;
     const writer = this.enc.writer;
     writer.reset();

src/json-crdt/codec/structural/compact/Encoder.ts

@@ -11,7 +11,7 @@ export class Encoder {
   protected clock?: ClockEncoder;
   protected model!: Model;
 
-  public encode(model: Model): t.JsonCrdtCompactDocument {
+  public encode(model: Model<any>): t.JsonCrdtCompactDocument {
     this.model = model;
     const isServerTime = model.clock.sid === SESSION.SERVER;
     const clock = model.clock;

src/json-crdt/codec/structural/verbose/Encoder.ts

@@ -8,7 +8,7 @@ import type * as types from './types';
 export class Encoder {
   protected model!: Model;
 
-  public encode(model: Model): types.JsonCrdtVerboseDocument {
+  public encode(model: Model<any>): types.JsonCrdtVerboseDocument {
     this.model = model;
     const clock = model.clock;
     const isServerClock = clock.sid === SESSION.SERVER;

src/json-crdt/model/Model.ts

@@ -37,7 +37,7 @@ export const enum ModelChangeType {
  * In instance of Model class represents the underlying data structure,
  * i.e. model, of the JSON CRDT document.
  */
-export class Model<RootJsonNode extends JsonNode = JsonNode> implements Printable {
+export class Model<N extends JsonNode = JsonNode> implements Printable {
   /**
    * Create a CRDT model which uses logical clock. Logical clock assigns a
    * logical timestamp to every node and operation. Logical timestamp consists
@@ -85,7 +85,7 @@ export class Model<RootJsonNode extends JsonNode = JsonNode> implements Printabl
    * so that the JSON document does not necessarily need to be an object. The
    * JSON document can be any JSON value.
    */
-  public root: RootNode<RootJsonNode> = new RootNode<RootJsonNode>(this, ORIGIN);
+  public root: RootNode<N> = new RootNode<N>(this, ORIGIN);
 
   /**
    * Clock that keeps track of logical timestamps of the current editing session
@@ -115,13 +115,13 @@ export class Model<RootJsonNode extends JsonNode = JsonNode> implements Printabl
   }
 
   /** @ignore */
-  private _api?: ModelApi<RootJsonNode>;
+  private _api?: ModelApi<N>;
 
   /**
    * API for applying local changes to the current document.
    */
-  public get api(): ModelApi<RootJsonNode> {
-    if (!this._api) this._api = new ModelApi<RootJsonNode>(this);
+  public get api(): ModelApi<N> {
+    if (!this._api) this._api = new ModelApi<N>(this);
     return this._api;
   }
 
@@ -302,29 +302,29 @@ export class Model<RootJsonNode extends JsonNode = JsonNode> implements Printabl
    * @param sessionId Session ID to use for the new model.
    * @returns A copy of this model with a new session ID.
    */
-  public fork(sessionId: number = randomSessionId()): Model<RootJsonNode> {
-    const copy = Model.fromBinary(this.toBinary());
+  public fork(sessionId: number = randomSessionId()): Model<N> {
+    const copy = Model.fromBinary(this.toBinary()) as unknown as Model<N>;
     if (copy.clock.sid !== sessionId && copy.clock instanceof ClockVector) copy.clock = copy.clock.fork(sessionId);
     copy.ext = this.ext;
-    return copy as Model<RootJsonNode>;
+    return copy;
   }
 
   /**
    * Creates a copy of this model with the same session ID.
    *
    * @returns A copy of this model with the same session ID.
    */
-  public clone(): Model<RootJsonNode> {
+  public clone(): Model<N> {
     return this.fork(this.clock.sid);
   }
 
   /**
    * Resets the model to equivalent state of another model.
    */
-  public reset(to: Model<RootJsonNode>): void {
+  public reset(to: Model<N>): void {
     this.index = new AvlMap<ITimestampStruct, JsonNode>(compare);
     const blob = to.toBinary();
-    decoder.decode(blob, this);
+    decoder.decode(blob, <any>this);
     this.clock = to.clock.clone();
     this.ext = to.ext.clone();
     const api = this._api;
@@ -337,7 +337,7 @@ export class Model<RootJsonNode extends JsonNode = JsonNode> implements Printabl
    *
    * @returns JSON/CBOR of the model.
    */
-  public view(): Readonly<JsonNodeView<RootJsonNode>> {
+  public view(): Readonly<JsonNodeView<N>> {
     return this.root.view();
   }
 
@@ -386,7 +386,6 @@ export class Model<RootJsonNode extends JsonNode = JsonNode> implements Printabl
           );
         },
         nl,
-        // (tab) => `View ${toTree(this.view(), tab)}`,
         (tab) =>
           `view${printTree(tab, [(tab) => String(JSON.stringify(this.view(), null, 2)).replace(/\n/g, '\n' + tab)])}`,
         nl,

src/json-crdt/model/__tests__/Model.events.spec.ts

@@ -1,3 +1,4 @@
+import {PatchBuilder} from '../../../json-crdt-patch';
 import {Model, ModelChangeType} from '../Model';
 
 describe('DOM Level 0, .onchange event system', () => {
@@ -8,13 +9,17 @@ describe('DOM Level 0, .onchange event system', () => {
       cnt++;
     };
     expect(cnt).toBe(0);
-    model.api.root({foo: 'bar'});
+    const builder = new PatchBuilder(model.clock.clone());
+    const objId = builder.json({foo: 123});
+    builder.root(objId);
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(1);
-    model.api.obj([]).set({hello: 123});
+    builder.insObj(objId, [['hello', builder.const(456)]]);
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(2);
     expect(model.view()).toStrictEqual({
-      foo: 'bar',
-      hello: 123,
+      foo: 123,
+      hello: 456,
     });
   });
 
@@ -25,9 +30,12 @@ describe('DOM Level 0, .onchange event system', () => {
       cnt++;
     };
     expect(cnt).toBe(0);
-    model.api.root({foo: 123});
+    const builder = new PatchBuilder(model.clock.clone());
+    builder.root(builder.json({foo: 123}));
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(1);
-    model.api.obj([]).set({foo: 123});
+    builder.root(builder.json({foo: 123}));
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(2);
   });
 
@@ -38,9 +46,13 @@ describe('DOM Level 0, .onchange event system', () => {
       cnt++;
     };
     expect(cnt).toBe(0);
-    model.api.root({foo: 123});
+    const builder = new PatchBuilder(model.clock.clone());
+    const objId = builder.json({foo: 123});
+    builder.root(objId);
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(1);
-    model.api.obj([]).set({foo: undefined});
+    builder.insObj(objId, [['foo', builder.const(undefined)]]);
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(2);
     expect(model.view()).toStrictEqual({});
   });
@@ -52,9 +64,13 @@ describe('DOM Level 0, .onchange event system', () => {
       cnt++;
     };
     expect(cnt).toBe(0);
-    model.api.root({foo: 123});
+    const builder = new PatchBuilder(model.clock.clone());
+    const objId = builder.json({foo: 123});
+    builder.root(objId);
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(1);
-    model.api.obj([]).set({bar: undefined});
+    builder.insObj(objId, [['bar', builder.const(undefined)]]);
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(2);
     expect(model.view()).toStrictEqual({foo: 123});
   });
@@ -66,38 +82,28 @@ describe('DOM Level 0, .onchange event system', () => {
       cnt++;
     };
     expect(cnt).toBe(0);
-    model.api.root({foo: 123});
+    const builder = new PatchBuilder(model.clock.clone());
+    const objId = builder.json({foo: 123});
+    builder.root(objId);
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(1);
-    model.api.root(123);
+    builder.root(builder.json(123));
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(2);
-    model.api.root('asdf');
+    builder.root(builder.json('asdf'));
+    model.applyPatch(builder.flush());
     expect(cnt).toBe(3);
   });
 
   describe('event types', () => {
-    it('should trigger the onchange event with a LOCAL event type', () => {
-      const model = Model.withLogicalClock();
-      let cnt = 0;
-      model.onchange = (type) => {
-        expect(type).toBe(ModelChangeType.LOCAL);
-        cnt++;
-      };
-      expect(cnt).toBe(0);
-      model.api.root({foo: 123});
-      expect(cnt).toBe(1);
-      model.api.obj([]).set({foo: 55});
-      expect(cnt).toBe(2);
-      expect(model.view()).toStrictEqual({foo: 55});
-    });
-
     it('should trigger the onchange event with a REMOTE event type', () => {
       const model = Model.withLogicalClock();
       let cnt = 0;
       model.onchange = (type) => {
         expect(type).toBe(ModelChangeType.REMOTE);
         cnt++;
       };
-      const builder = model.api.builder;
+      const builder = new PatchBuilder(model.clock.clone());
       builder.root(builder.json({foo: 123}));
       const patch = builder.flush();
       expect(cnt).toBe(0);

src/json-crdt/model/__tests__/Model.types.spec.ts

@@ -2,7 +2,7 @@ import {Model} from '../Model';
 import type {ConNode, ObjNode, StrNode} from '../../nodes';
 
 test('can add TypeScript types to Model view', () => {
-  const model = Model.withLogicalClock() as Model<
+  const model = Model.withLogicalClock() as any as Model<
     ObjNode<{
       foo: StrNode;
       bar: ConNode<number>;

src/json-crdt/model/api/ModelApi.ts

@@ -1,10 +1,12 @@
+import {FanOut} from 'thingies/es2020/fanout';
 import {VecNode, ConNode, ObjNode, ArrNode, BinNode, StrNode, ValNode} from '../../nodes';
 import {ApiPath, ArrApi, BinApi, ConApi, NodeApi, ObjApi, StrApi, VecApi, ValApi} from './nodes';
 import {Emitter} from '../../../util/events/Emitter';
 import {Patch} from '../../../json-crdt-patch/Patch';
 import {PatchBuilder} from '../../../json-crdt-patch/PatchBuilder';
 import {ModelChangeType, type Model} from '../Model';
-import type {JsonNode} from '../../nodes';
+import {SyncStore} from '../../../util/events/sync-store';
+import type {JsonNode, JsonNodeView} from '../../nodes';
 
 export interface ModelApiEvents {
   /**
@@ -26,7 +28,7 @@ export interface ModelApiEvents {
  *
  * @category Local API
  */
-export class ModelApi<Value extends JsonNode = JsonNode> {
+export class ModelApi<N extends JsonNode = JsonNode> implements SyncStore<JsonNodeView<N>> {
   /**
    * Patch builder for the local changes.
    */
@@ -42,15 +44,19 @@ export class ModelApi<Value extends JsonNode = JsonNode> {
   /**
    * @param model Model instance on which the API operates.
    */
-  constructor(public readonly model: Model<Value>) {
+  constructor(public readonly model: Model<N>) {
     this.builder = new PatchBuilder(this.model.clock);
+    this.model.onchange = this.queueChange;
   }
 
+  public readonly changes = new FanOut<ModelChangeType>();
+
   /** @ignore */
   private queuedChanges: undefined | Set<ModelChangeType> = undefined;
 
-  /** @ignore */
+  /** @ignore @deprecated */
   private readonly queueChange = (changeType: ModelChangeType): void => {
+    this.changes.emit(changeType);
     let changesQueued = this.queuedChanges;
     if (changesQueued) {
       changesQueued.add(changeType);
@@ -67,19 +73,16 @@ export class ModelApi<Value extends JsonNode = JsonNode> {
     });
   };
 
-  /** @ignore */
-  private et: undefined | Emitter<ModelApiEvents> = undefined;
+  /** @ignore @deprecated */
+  private et: Emitter<ModelApiEvents> = new Emitter();
 
   /**
    * Event target for listening to {@link Model} changes.
+   *
+   * @deprecated
    */
   public get events(): Emitter<ModelApiEvents> {
-    let et = this.et;
-    if (!et) {
-      this.et = et = new Emitter();
-      this.model.onchange = this.queueChange;
-    }
-    return et;
+    return this.et;
   }
 
   /**
@@ -277,4 +280,14 @@ export class ModelApi<Value extends JsonNode = JsonNode> {
     this.events.emit(event);
     return patch;
   }
+
+  // ---------------------------------------------------------------- SyncStore
+
+  public readonly subscribe = (callback: () => void) => {
+    const listener = () => callback();
+    this.events.on('change', listener);
+    return () => this.events.off('change', listener);
+  };
+
+  public readonly getSnapshot = () => this.view() as any;
 }