@etsoo/appscript/src/bridges/FlutterHost.ts

Applications shared TypeScript framework

import { DataTypes, ExtendUtils } from "@etsoo/shared";
import { BridgeHostName, IBridgeHost } from "./IBridgeHost";

// Call handler type
type CallHandlerType = (
  name: string,
  ...args: unknown[]
) => PromiseLike<DataTypes.StringRecord | void>;

/**
 * Flutter JavaScript Host
 * https://inappwebview.dev/docs/javascript/communication/
 */
export class FlutterHost implements IBridgeHost {
  /**
   * Name
   */
  readonly name = BridgeHostName.Flutter;

  /**
   * Start Url
   */
  private startUrl: string | null | undefined;

  /**
   * Cached commands
   */
  private cachedCommands: Record<string, unknown[]> = {};

  /**
   * Constructor
   * @param callHandler Call handler
   */
  constructor(private host: { callHandler?: CallHandlerType }) {
    window.addEventListener("flutterInAppWebViewPlatformReady", (_event) => {
      if (this.host.callHandler == null) return;

      for (const key in this.cachedCommands) {
        // Args
        const args = this.cachedCommands[key];

        // Execute
        this.host.callHandler(key, ...args);

        // Remove the key
        delete this.cachedCommands[key];
      }
    });
  }

  cacheCommand(name: string, ...args: unknown[]): void {
    this.cachedCommands[name] = args;
  }

  changeCulture(locale: string): void {
    if (this.host.callHandler) this.host.callHandler("changeCulture", locale);
    else this.cacheCommand("changeCulture", locale);
  }

  closable(): boolean {
    return false;
  }

  exit(): void {
    if (this.host.callHandler) this.host.callHandler("exit");
    else this.cacheCommand("exit");
  }

  async getLabels<T extends string>(...keys: T[]) {
    // Try 500 miliseconds
    let count = 5;
    while (this.host.callHandler == null) {
      count--;
      await ExtendUtils.sleep(100);

      if (count === 0) break;
    }

    const init: any = {};

    if (this.host.callHandler == null) return init;

    const result = (await this.host.callHandler("getLabels")) ?? {};

    return keys.reduce(
      (a, v) => ({
        ...a,
        [v]: result[v] ?? ""
      }),
      init
    );
  }

  getStartUrl(): string | null | undefined {
    return this.startUrl;
  }

  loadApp(name: string, startUrl?: string): void {
    this.startUrl = startUrl;
    if (this.host.callHandler) this.host.callHandler("loadApp", name, startUrl);
    else this.cacheCommand("loadApp", name, startUrl);
  }

  userAuthorization(authorized: boolean): void {
    if (this.host.callHandler)
      this.host.callHandler("userAuthorization", authorized);
    else this.cacheCommand("userAuthorization", authorized);
  }

  onUpdate(func: (app: string, version: string) => void) {}

  setTitle(title: string) {}
}