src/Form.ts

   1 import { Line } from './Line';
   2 import { InconsistencyError, NotFoundError } from './Errors';
   3
   4 export default abstract class Form<I = unknown> {
   5   private _lines: Line<any>[] = [];
   6   private _input?: I;
   7
   8   abstract get name(): string;
   9
  10   constructor(input?: I) {
  11     this._input = input;
  12     this.getLines().map(this.addLine.bind(this));
  13   }
  14
  15   protected abstract getLines(): Line<any>[];
  16
  17   private addLine(line: Line<any>) {
  18     if (line.form !== undefined) {
  19       throw new InconsistencyError('Line is already in a Form');
  20     }
  21     try {
  22       this.getLine(line.id);
  23     } catch {
  24       line.form = this;
  25       this._lines.push(line);
  26       return;
  27     }
  28     throw new InconsistencyError('Cannot add a line with a duplicate identifier');
  29   }
  30
  31   getLine(id: string): Line<any> {
  32     const lines = this._lines.filter(l => l.id === id);
  33     if (lines.length == 0) {
  34       throw new NotFoundError(id);
  35     }
  36     return lines[0];
  37   }
  38
  39   getInput<K extends keyof I>(name: K): I[K] {
  40     if (!(name in this._input)) {
  41       throw new NotFoundError(`No input with key ${name} on form ${this.name}`);
  42     }
  43     return this._input[name];
  44   }
  45 };
  46
  47 export interface SupportsMultipleCopies extends Form {
  48   aggregate(forms: Form[]): this;
  49 };
  50
  51 export function supportsMultipleCopies(f: object): f is SupportsMultipleCopies {
  52   return f instanceof Form && 'aggregate' in f;
  53 };