Captcha Provider 
这里对模块a-captchasimple的核心源码进行解析,从而说明如何开发一个新的 Captcha Provider
创建Captcha Provider 
比如,在模块a-captchasimple中创建一个 Captcha Provider: imageText
1. Cli命令 
bash
$ vona :create:bean captchaProvider imageText --module=a-captchasimple2. 菜单命令 
TIP
右键菜单 - [模块路径]: Vona Bean/Captcha Provider
Captcha Provider定义 
typescript
export type TypeCaptchaProviderImageTextToken = string;
export type TypeCaptchaProviderImageTextPayload = string;
export type TypeCaptchaProviderImageTextData = ICaptchaProviderData<TypeCaptchaProviderImageTextToken, TypeCaptchaProviderImageTextPayload>;
export type TypeCaptchaProviderImageTextType = 'char' | 'math';
const CaptchaProviderImageTextTypes = ['char', 'math'] as const;
export interface ICaptchaProviderOptionsImageText extends IDecoratorCaptchaProviderOptions {
  type?: TypeCaptchaProviderImageTextType;
  fontPath?: string;
  opts: ConfigObject;
}
@CaptchaProvider<ICaptchaProviderOptionsImageText>({
  opts: {
    size: 4,
    color: true,
  },
})
class CaptchaProviderImageText {
  async create(options) {
    this._confirmFont(options);
    let type = options.type;
    if (!type) {
      type = CaptchaProviderImageTextTypes[getRandomInt(2, 0)];
    }
    const captcha = type === 'char' ? svgCaptcha.create(options.opts) : svgCaptcha.createMathExpr(options.opts);
    return { token: captcha.text, payload: svg64(captcha.data) };
  }
  async verify(
    token,
    tokenInput,
    _options,
  ) {
    return !!tokenInput && !!token && tokenInput.toLowerCase() === token.toLowerCase();
  }
}TypeCaptchaProviderImageTextToken: token 类型,不同的 Provider 可能有不同的 token 类型TypeCaptchaProviderImageTextPayload: payload 类型,不同的 Provider 可能有不同的 payload 类型TypeCaptchaProviderImageTextData: 当前 Provider 对应的 Captcha Data 类型ICaptchaProviderOptionsImageText: 当前 Provider 的参数。不同的 Provider 可以提供不同的参数配置。比如,该 Provider 基于svg-captcha实现文字图片的验证码能力,因此相应的提供 svg-captcha 所需的参数:type/fontPath/optscreate: 创建 captcha 数据verify: 校验 captcha token 是否正确
App Config配置 
可以在 App Config 中配置 Captcha Provider 参数
src/backend/config/config/config.ts
typescript
// onions
config.onions = {
  captchaProvider: {
    'a-captchasimple:imageText': {
      type: 'char',
      opts: {
        size: 4,
        color: true,
      },
    },
  },
};