moleculer-cron

Cron mixin Node-Cron.

Description

Easy to use cron with moleculer!

Install

1$ npm install moleculer-cron --save

Usage

Create cron service

Specify all of your cron task inside of the constructor of the addon.

1const Cron = require("moleculer-cron");
2
3
4broker.createService({
5    name: "cron-job",
6
7   mixins: [Cron],
8
9    crons: [
10        {
11            name: "JobHelloWorld",
12            cronTime: '* * * * *',
13            onTick: function() {
14
15                console.log('JobHelloWorld ticked');
16
17                this.getLocalService("cron-job")
18                    .actions.say()
19                    .then((data) => {
20                        console.log("Oh!", data);
21                    });
22            },
23            runOnInit: function() {
24                console.log("JobHelloWorld is created");
25            },
26            manualStart: true,
27            timeZone: 'America/Nipigon'
28        },
29        {
30            name: "JobWhoStartAnother",
31            cronTime: '* * * * *',
32            onTick: function() {
33
34                console.log('JobWhoStartAnother ticked');
35
36                var job = this.getJob("JobHelloWorld");
37
38                if (!job.lastDate()) {
39                    job.start();
40                } else {
41                    console.log("JobHelloWorld is already started!");
42                }
43
44            },
45            runOnInit: function() {
46                console.log("JobWhoStartAnother is created");
47            },
48            timeZone: 'America/Nipigon'
49        }
50    ],
51
52    actions: {
53
54        say: {
55            handler(ctx) {
56                return "HelloWorld!";
57            }
58        }
59
60    }
61
62});

How to use it (edited Node-Cron documentation)

Available Cron patterns:

Asterisk. E.g. *
Ranges. E.g. 1-3,5
Steps. E.g. */2

Read up on cron patterns here. Note the examples in the link have five fields, and 1 minute as the finest granularity, but this library has six fields, with 1 second as the finest granularity.

Cron Ranges

When specifying your cron values you'll need to make sure that your values fall within the ranges. For instance, some cron's use a 0-7 range for the day of week where both 0 and 7 represent Sunday. We do not.

• Seconds: 0-59
• Minutes: 0-59
• Hours: 0-23
• Day of Month: 1-31
• Months: 0-11 (Jan-Dec)
• Day of Week: 0-6 (Sun-Sat)

API

Parameter Based

• Cron

  • cronTime - [REQUIRED] - The time to fire off your job. This can be in the form of cron syntax or a JS Date object.
  • onTick - [REQUIRED] - The function to fire at the specified time.
  • name - [OPTIONAL] - Set a name to the job, will be automaticly generated if you don't set it
  • onComplete - [OPTIONAL] - A function that will fire when the job is complete, when it is stopped.
  • manualStart - [OPTIONAL] - Specifies whether to start the job just before exiting the constructor. By default this is set to false. If left at default you will need to call job.start() in order to start the job (assuming job is the variable you set the cronjob to). This does not immediately fire your onTick function, it just gives you more control over the behavior of your jobs.
  • timeZone - [OPTIONAL] - Specify the timezone for the execution. This will modify the actual time relative to your timezone. If the timezone is invalid, an error is thrown. You can check all timezones available at Moment Timezone Website.
  • runOnInit - [OPTIONAL] - This will be fired on start() function as soon as the requisit initialization has happened.

• CronJob

  • start - Runs your job.
  • stop - Stops your job.
  • setTime - Change the time for the CronJob. Param must be a CronTime from getCronTime.
  • lastDate - Tells you the last execution date.
  • nextDates - Provides an array of the next set of dates that will trigger an onTick.
  • addCallback - Allows you to add onTick callbacks.

• getCronTime(time)

  • Return a CronTime instance
    • time - [REQUIRED] - The time to fire off your job. This can be in the form of cron syntax or a JS Date object.