Task

+++ title = "Tasks" description = "" date = 2021-05-01T18:10:00+00:00 updated = 2021-05-01T18:10:00+00:00 draft = false weight = 4 sort_by = "weight" template = "docs/page.html"

[extra] lead = "" toc = true top = false flair =[] +++

Tasks in Loco serve as ad-hoc functionalities to handle specific aspects of your application. Whether you need to fix data, send emails, delete a user, or update a customer order, creating a dedicated task for each scenario provides a flexible and efficient solution. You can run tasks manually or by scheduling the task.

Creating tasks is worthwhile for several reasons:

• Automation of Manual Work: Tasks automate manual processes, streamlining repetitive actions.
• Utilization of Familiar Components: Leverage your app's models, libraries, and existing logic within tasks.
• Elimination of UI Development: Tasks don't require building user interfaces, focusing solely on backend operations.
• Potential for UI Automation: If necessary, tasks can be automated with a UI by integrating with job-running tools like Jenkins.

Each task is designed to parse command-line arguments into flags, utilizing the yargs-parsed output of your CLI.

Creating a Task with the CLI Generator

Loco provides a convenient code generator to simplify the creation of a starter task connected to your project. Use the following command to generate a task:

Generate the task:

Generate a Task based on the given name

Usage: demo_app-cli generate task [OPTIONS] <NAME>

Arguments:
  <NAME>  Name of the thing to generate

Options:
  -e, --environment <ENVIRONMENT>  Specify the environment [default: development]
  -h, --help                       Print help
  -V, --version                    Print version

Running a Task

Execute the task you created in the previous step using the following command:

cargo loco task <TASK_NAME>

Running a Task with Parameters

To pass parameters to a task, add a list of key:value to the command

[PARAMS]...  Task params (e.g. <`my_task`> foo:bar baz:qux)`

cargo loco task <TASK_NAME> [PARAMS]...

Then use that value using cli_arg in the run method of the task

async fn run(&self, app_context: &AppContext, vars: &task::Vars) -> Result<()> {
    let foo = vars.cli_arg("foo");
    Ok(())
}

Listing All Tasks

To view a list of all tasks that have been executed, use the following command:

cargo loco task

Creating a Task manually

If you prefer a manual approach to creating tasks in Loco, you can follow these steps:

1. Create a Task File

Start by creating a new file under the path src/tasks. For example, let's create a file named example.rs:

use loco_rs::prelude::*;

pub struct Foo;
#[async_trait]
impl Task for Foo {
    fn task(&self) -> TaskInfo {
        TaskInfo {
            name: "foo".to_string(),
            detail: "run foo task".to_string(),
        }
    }
    async fn run(&self, _app_context: &AppContext, _vars: &task::Vars) -> Result<()> {
        Ok(())
    }
}

2. Load the File in mod.rs

Next, ensure that you load the newly created task file in the mod.rs file within the src/tasks folder.

3. Register the Task in App Hooks

In your App hook implementation (e.g., App struct), register the task in the register_tasks function:

// src/app.rs

pub struct App;
#[async_trait]
impl Hooks for App {
    ...

    fn register_tasks(tasks: &mut Tasks) {
        tasks.register(tasks::example::ExampleTask);
    }

    ...
}

These steps ensure that your manually created task, such as ExampleTask, is integrated into Loco's task management system.