Cron

Cron jobs in Zibri use the node-cron package and its cron syntax under the hood.

Defining a cron job

To define a job it needs to extend the CronJob class. Below is a simple example that just logs to the console each second:

// src/cron/status.cron-job.ts
import { CronJob, inject, Injectable, LoggerInterface, ZIBRI_DI_TOKENS, InitialCronConfig } from 'zibri';

@Injectable()
export class StatusCronJob extends CronJob {
    readonly initialConfig: InitialCronConfig = {
        name: 'Status',
        cron: '* * * * * *',
        active: false
    };

    async onTick(): Promise<void> {
        await inject<LoggerInterface>(ZIBRI_DI_TOKENS.LOGGER).info(`is running ${this.name}`);
    }
}
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Registering the cron job

For Zibri to be actual able to pickup the cron job start it automatically you need to provide its class at the index.ts:

// src/index.ts
import { StatusCronJob } from './cron';
// ...

const app: ZibriApplication = new ZibriApplication({
    name: 'Api',
    baseUrl: 'http://localhost:3000',
    plugins: [
        // ...
    ],
    controllers: [
        // ...
    ],
    websocketControllers: [
        // ...
    ],
    dataSources: [
        // ...
    ],
    cronJobs: [StatusCronJob],
    version,
    providers
});
// ...
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Behaviour

The job is first initialized with the given initial config. Which in this case means that

• its name is 'Status'
• it would run every second
• but is not active yet.

At that first startup, the cron job is saved as a cron job entity in a data source. After that you can programmatically change its configuration, like setting active to true or changing the cron schedule.

While this is pretty useful, it might not always be what you want. A downside of this is for example that changing the initial config after the cron job has already been saved in the data source does not have any effect. If you want the hardcoded configuration inside the cron job to be the single source of truth you can set the syncToDataSource flag to false in the initial config.