Global Interceptor

Create Interceptor

For example, we create a Global Interceptor logger in the module demo-student

1. Cli command

$ vona :create:bean interceptor logger --module=demo-student --boilerplate=global

2. Menu command

TIP

Context Menu - [Module Path]: Vona Aspect/Interceptor Global

Interceptor Definition

export interface IInterceptorOptionsLogger extends IDecoratorInterceptorOptionsGlobal {}

@Interceptor<IInterceptorOptionsLogger>({ global: true })
export class InterceptorLogger extends BeanBase implements IInterceptorExecute {
  async execute(_options: IInterceptorOptionsLogger, next: Next) {
    const timeBegin = Date.now();
    const res = await next();
    const timeEnd = Date.now();
    console.log('time: ', timeEnd - timeBegin);
    return res;
  }
}

• IInterceptorOptionsLogger: Defines interceptor parameters
• execute: Outputs execution time

Using Interceptor

Unlike local interceptor, the system automatically loads global interceptors and makes them effective

Interceptor Parameters

You can define parameters for interceptor, allowing for more flexible configuration of interceptor logic

For example, define the prefix parameter for the logger interceptor to control the output format

1. Defining parameter types

export interface IInterceptorOptionsLogger extends IDecoratorInterceptorOptionsGlobal {
+ prefix: string;
}

2. Providing default values ​​for parameters

@Interceptor<IInterceptorOptionsLogger>({
  global: true,
+ prefix: 'time',
})

3. Using Parameters

export interface IInterceptorOptionsLogger extends IDecoratorInterceptorOptionsGlobal {
  prefix: string;
}

@Interceptor<IInterceptorOptionsLogger>({
  global: true,
  prefix: 'time',
})
class InterceptorLogger {
  async execute(options: IInterceptorOptionsLogger, next: Next) {
    const timeBegin = Date.now();
    const res = await next();
    const timeEnd = Date.now();
-   console.log('time: ', timeEnd - timeBegin);
+   console.log(`${options.prefix}: `, timeEnd - timeBegin);
    return res;
  }
}

4. Specify parameters when using

You can specify global interceptor parameters for a specific API

class ControllerStudent {
  @Web.get()
+ @Aspect.interceptorGlobal('demo-student:logger', { prefix: 'elapsed' })
  async findMany() {}
}

• When using interceptor, just provide the parameter value directly

5. App config

Interceptor parameters can be configured in App config

src/backend/config/config/config.ts

// onions
config.onions = {
  interceptor: {
    'demo-student:logger': {
      prefix: 'elapsed',
    },
  },
};

6. Parameters precedence

Specify parameters when using > App config > Default values

Interceptor Order

Since global interceptors ard loaded and enabled by default, VonaJS provides two parameters to control the order in which interceptor is loaded

1. dependencies

For example, the system has a built-in global interceptor a-body:bodyRes, and we hope that the loading order is as follows: a-body:bodyRes > Current

@Interceptor({
  global: true,
+ dependencies: 'a-body:bodyRes',
  prefix: 'time',
})
class InterceptorLogger {}

2. dependents

The order of dependents is just the opposite of dependencies. We hope that the loading order is as follows: Current > a-body:bodyRes

@Interceptor({
  global: true,
+ dependents: 'a-body:bodyRes',
  prefix: 'time',
})
class InterceptorLogger {}

Interceptor enable/disable

You can control enable/disable of global interceptor for certain APIs

1. Enable

• Disable for an API

class ControllerStudent {
  @Web.get()
+ @Aspect.interceptorGlobal('demo-student:logger', { enable: false })
  async findMany() {}
}

• Disable for all APIs

src/backend/config/config/config.ts

// onions
config.onions = {
  interceptor: {
    'demo-student:logger': {
+     enable: false,
    },
  },
};

2. Meta

Allows global interceptor to take effect in a specified operating environment

Name	Type	Description
flavor	string|string[]	See: Runtime Environments and Flavors
mode	string|string[]	See: Runtime Environments and Flavors
instanceName	string|string[]	See: Multi-Instance/Multi-Tenancy
host	string|string[]	Host

• Example

@Interceptor({
  global: true,
+ meta: {
+   flavor: 'normal',
+   mode: 'dev',
+   instanceName: '',
+   host: 'localhost:7102',
+ },
})
class InterceptorLogger {}

3. match/ignore

You can enable/disable global interceptor for some specific APIs

Name	Type	Description
match	string|regexp|(string|regexp)[]	For which APIs to enable
ignore	string|regexp|(string|regexp)[]	For which APIs to disable

Inspect

You can directly inspect the currently effective global interceptor list in the Controller action

class ControllerStudent {
  @Web.get()
  async findMany() {
+   this.bean.onion.interceptor.inspect();
  }
}

• this.bean.onion: Get the global Service instance onion
• .interceptor: Get the Service instance related to the interceptor
• .inspect: Output the currently effective global interceptor list

When accessing the findMany API, the current list of global interceptor in effect will be automatically output to the console, as shown below: