初始化项目

data/src/main/ets/grid/FormViewModel.ets

@@ -0,0 +1,128 @@
+/**
+ * 表单视图模型（1.7.2）。
+ *
+ * 单行记录的表单编辑：字段定义（可编辑/只读/必填），值的脏检测与回滚，
+ * 提交时产出 CellChange 交给 TableEditor 生成 UPDATE。
+ */
+import { CellChange } from './TableEditor';
+
+export interface FieldSpec {
+  column: string;
+  label: string;
+  editable: boolean;
+  required: boolean;
+}
+
+export class FormViewModel {
+  private readonly fields: FieldSpec[];
+  private original: Map<string, string> = new Map<string, string>();
+  private current: Map<string, string> = new Map<string, string>();
+
+  constructor(fields: FieldSpec[]) {
+    this.fields = fields.slice();
+  }
+
+  fields_(): FieldSpec[] {
+    return this.fields.slice();
+  }
+
+  /** 载入一行数据（重置脏状态）。 */
+  load(values: Map<string, string>): void {
+    this.original = new Map<string, string>();
+    this.current = new Map<string, string>();
+    for (let i = 0; i < this.fields.length; i++) {
+      const column: string = this.fields[i].column;
+      const value: string | undefined = values.get(column);
+      this.original.set(column, value === undefined ? '' : value);
+      this.current.set(column, value === undefined ? '' : value);
+    }
+  }
+
+  get(column: string): string {
+    const value: string | undefined = this.current.get(column);
+    return value === undefined ? '' : value;
+  }
+
+  /** 修改值；只读列或未知列忽略。 */
+  set(column: string, value: string): boolean {
+    const field: FieldSpec | undefined = this.fieldOf(column);
+    if (field === undefined || !field.editable) {
+      return false;
+    }
+    this.current.set(column, value);
+    return true;
+  }
+
+  isEditable(column: string): boolean {
+    const field: FieldSpec | undefined = this.fieldOf(column);
+    return field !== undefined && field.editable;
+  }
+
+  /** 脏字段（值发生过变化）。 */
+  dirtyFields(): string[] {
+    const out: string[] = [];
+    for (let i = 0; i < this.fields.length; i++) {
+      const column: string = this.fields[i].column;
+      if (this.get(column) !== this.originalOf(column)) {
+        out.push(column);
+      }
+    }
+    return out;
+  }
+
+  isDirty(): boolean {
+    return this.dirtyFields().length > 0;
+  }
+
+  /** 回滚到载入时的值。 */
+  revert(): void {
+    this.current = new Map<string, string>();
+    this.original.forEach((value: string, column: string) => {
+      this.current.set(column, value);
+    });
+  }
+
+  /** 必填校验；返回错误列与消息。 */
+  validate(): string[] {
+    const errors: string[] = [];
+    for (let i = 0; i < this.fields.length; i++) {
+      const field: FieldSpec = this.fields[i];
+      if (field.required && this.get(field.column).trim().length === 0) {
+        errors.push(field.column + ' is required');
+      }
+    }
+    return errors;
+  }
+
+  /** 产出变更（供 TableEditor 提交）；必填不通过时返回空数组。 */
+  changes(): CellChange[] {
+    if (this.validate().length > 0) {
+      return [];
+    }
+    const out: CellChange[] = [];
+    const dirty: string[] = this.dirtyFields();
+    for (let i = 0; i < dirty.length; i++) {
+      out.push({
+        rowIndex: 0,
+        column: dirty[i],
+        oldValue: this.originalOf(dirty[i]),
+        newValue: this.get(dirty[i])
+      });
+    }
+    return out;
+  }
+
+  private originalOf(column: string): string {
+    const value: string | undefined = this.original.get(column);
+    return value === undefined ? '' : value;
+  }
+
+  private fieldOf(column: string): FieldSpec | undefined {
+    for (let i = 0; i < this.fields.length; i++) {
+      if (this.fields[i].column === column) {
+        return this.fields[i];
+      }
+    }
+    return undefined;
+  }
+}