[WIP] Apply schema to model

Author: hackerwins

src/commands.ts

@@ -0,0 +1,48 @@
+import { Model } from '../model/model';
+import { Range } from '../model/types';
+import { Operation } from '../model/operations';
+
+export type Command = {
+  ops: Array<Operation>;
+};
+
+export function insertText(range: Range, text: string): Command {
+  return {
+    ops: [
+      {
+        type: 'edit',
+        range,
+        value: [{ type: 'text', text }],
+      },
+    ],
+  };
+}
+
+export function splitBlock(range: Range): Command {
+  // TODO(hackerwins): Implement this according to the schema.
+  return {
+    ops: [
+      {
+        type: 'edit',
+        range,
+        value: [{ type: 'p' }],
+      },
+    ],
+  };
+}
+
+/**
+ * `execute` executes the command on the model and returns inverse command.
+ */
+export function execute(model: Model, command: Command): Command {
+  const ops = [];
+
+  for (const op of command.ops) {
+    const inverse = model.apply(op);
+    ops.push(inverse);
+  }
+
+  return {
+    ops: ops,
+  };
+}

src/commands/commands.ts

@@ -4,13 +4,15 @@ import { Observable, Unsubscribe } from './utils/observable';
 
 import { View as View } from './view/view';
 import { Model } from './model/model';
-import { Command, execute } from './commands';
+import { Command, execute, insertText } from './commands/commands';
+import { SchemaSpec, BasicSchema } from './model/schema';
 
 /**
  * `EditorOptions` is an object that contains the initial value of the editor
  *  and the plugins that should be initialized.
  */
 type EditorOptions = {
+  schema: SchemaSpec;
   initialValue?: string;
   plugins?: Array<Module>;
 };
@@ -28,7 +30,10 @@ export class Editor extends Observable<Array<Command>> implements Module {
 
   private plugins: Array<Module>;
 
-  static create(container: HTMLDivElement, opts: EditorOptions = {}) {
+  static create(
+    container: HTMLDivElement,
+    opts: EditorOptions = { schema: BasicSchema },
+  ) {
     const editor = new Editor(container, opts);
     editor.initialize();
     return editor;
@@ -38,7 +43,7 @@ export class Editor extends Observable<Array<Command>> implements Module {
     super();
 
     this.view = View.create(container);
-    this.model = Model.create(opts.initialValue || '');
+    this.model = Model.create(opts.schema, opts.initialValue || '');
     this.history = new History<Command>((command) =>
       execute(this.model, command),
     );
@@ -50,7 +55,7 @@ export class Editor extends Observable<Array<Command>> implements Module {
 
   initialize() {
     // 01. Initialize the view with the model's content.
-    this.view.setValue(this.model.getValue());
+    this.view.setValue(this.model.toXML());
 
     // 02. Upstream: view creates commands and then the editor executes them.
     this.unsubscribes.push(
@@ -63,13 +68,14 @@ export class Editor extends Observable<Array<Command>> implements Module {
 
     // 03. Downstream: If the model changes, the view should be updated.
     this.unsubscribes.push(
-      this.model.subscribe((value) => {
+      this.model.subscribe(() => {
         // Prevent downstream updates if the view is the source of change.
         if (this.isUpstream) {
           return;
         }
 
-        this.view.setValue(value);
+        // TODO(hackerwins): We need to figure out how to update the view.
+        // this.view.setValue(value);
       }),
     );
 
@@ -126,11 +132,11 @@ export class Editor extends Observable<Array<Command>> implements Module {
    * TODO(hackerwins): Find a better way to provide APIs.
    */
   insertText(text: string) {
-    this.execute({
-      t: 'e',
-      s: this.model.getValue().length,
-      e: this.model.getValue().length,
-      v: text,
-    });
+    let range = this.view.getSelection();
+    if (!range) {
+      range = this.model.getContentEndRange();
+    }
+
+    this.execute(insertText(range, text));
   }
 }

src/editor.ts

@@ -6,7 +6,12 @@ import { Devtools } from './plugins/devtools';
 const editor = Editor.create(
   document.querySelector<HTMLDivElement>('#editor')!,
   {
-    initialValue: 'Hello,',
+    initialValue: '<p>Hello,</p>',
+    schema: {
+      root: { children: 'p*' },
+      p: { children: 'text*' },
+      text: {},
+    },
     plugins: [
       Toolbar.create(document.querySelector<HTMLDivElement>('#toolbar')!, {
         buttons: ['destroy', 'undo', 'redo'],

src/main.ts

@@ -1,33 +1,143 @@
 import { Observable } from '../utils/observable';
+import { Node, Text, Element, Range, NodePos } from './types';
+import { Schema, SchemaSpec } from './schema';
+import { Operation } from './operations';
+import {
+  insertAfter,
+  insertBefore,
+  nodesBetween,
+  pathOf,
+  removeNode,
+  splitText,
+  toNodePos,
+  toXML,
+} from './nodes';
+import { firstOf, lastOf } from '../utils/array';
+import { isLeftMost } from './nodepos';
+import { isCollapsed } from './range';
 
-// TODO(hackerwins): Build a tree-based model with schema validation.
-export class Model extends Observable<string> {
-  private value: string;
+export class Model extends Observable<Array<Operation>> {
+  private schema: Schema;
+  private root: Element;
 
-  static create(initialValue: string): Model {
-    return new Model(initialValue);
+  static create(spec: SchemaSpec, initialValue: string): Model {
+    const schema = new Schema(spec);
+    const value = schema.fromXML(initialValue);
+    return new Model(schema, value);
   }
 
-  constructor(value: string) {
+  constructor(schema: Schema, value: Node) {
     super();
-    this.value = value;
+    this.schema = schema;
+    this.root = value;
   }
 
-  setValue(value: string): void {
-    this.value = value;
-    this.notify(this.value);
+  createText(value: string): Text {
+    return this.schema.create('text', value) as Text;
   }
 
-  getValue(from?: number, to?: number): string {
-    if (from !== undefined && to !== undefined) {
-      return this.value.slice(from, to);
+  toXML(): string {
+    return toXML(this.root);
+  }
+
+  apply(op: Operation): Operation {
+    switch (op.type) {
+      case 'edit':
+        return this.edit(op.range, op.value);
+      case 'move':
+        return this.move(/*op.source, op.target*/);
+      default:
+        throw new Error(`invalid operation type: ${op}`);
+    }
+  }
+
+  edit(range: Range, values: Array<Node>): Operation {
+    // NOTE(hackerwins): To keep the node of the position, we need to split the
+    // text node at the end of the range.
+    const end = this.nodePosOf(range.e);
+    const start = isCollapsed(range) ? end : this.nodePosOf(range.s);
+
+    const nodesToRemove: Array<Node> = [];
+    for (const [node, type] of nodesBetween(this.root, start, end)) {
+      if (type === 'open') {
+        continue;
+      }
+
+      nodesToRemove.push(node);
+    };
+
+    for (const node of nodesToRemove) {
+      removeNode(node);
+    }
+
+    if (isLeftMost(start)) {
+      insertBefore(start.node, ...values);
+    } else {
+      insertAfter(start.node, ...values);
+    }
+
+
+    const firstNode = firstOf(values)!;
+    const lastNode = lastOf(values)!;
+    const startPath = pathOf(firstNode, this.root);
+    const endPath = pathOf(lastNode, this.root);
+
+    return {
+      type: 'edit',
+      range: { s: startPath, e: endPath },
+      value: nodesToRemove
+    };
+  }
+
+  /**
+   * `nodePosOf` returns the node position of the given path.
+   */
+  nodePosOf(path: Array<number>, withSplitText: boolean = true): NodePos {
+    const pos = toNodePos(path, this.root);
+    if (!withSplitText) {
+      return pos;
+    }
+
+    const newNode = splitText(pos);
+    if (!newNode) {
+      return pos;
+    }
+
+    return {
+      node: newNode,
+      offset: 0,
+    };
+  }
+
+  /**
+   * `getContentEndRange` returns the range of the end of the content in the
+   *  model.
+   */
+  getContentEndRange(): Range {
+    const path = [];
+
+    let node = this.root;
+    while (node) {
+      if (node.type === 'text') {
+        const text = node as Text;
+        path.push(text.text.length);
+        break;
+      }
+
+      const elem = node as Element;
+      const children = elem.children || [];
+      if (children.length === 0) {
+        break;
+      }
+
+      path.push(children.length - 1);
+      node = lastOf(children)!;
     }
 
-    return this.value;
+    return { s: path, e: path };
   }
 
-  edit(start: number, end: number, text: string): void {
-    this.value = this.value.slice(0, start) + text + this.value.slice(end);
-    this.notify(this.value);
+  move(/*source: Range, target: Range*/): Operation {
+    throw new Error('Method not implemented.');
   }
 }