Mantra official documentation

06-component-hooks-registering.md

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Component Hooks Registering

Mantra follows a microkernel software architecture and acts like a glue for the components in all its essential functionality.

In some way, Mantra can be considered as a hook system, cause all components assets are exposed by hooks that components exposes and implements.

These hooks are defined at onStart method in each component or by definition in files.

As we will see in this documentation, most of those hooks can be defined implicity as well following some naming conventions in the files of the component, reducing in that way the code needed.

Components can define a number of services, like views, blocks, APIs, and the like.

To do so, a component should indicate what exactly registers in onStart method of the component, as indicated in Component Definition section.

This is what we call a Mantra hook.

Each kind of hook is described in the following sections and their definition shortcuts.

To register hooks in onStart() method of any component, Mantra API returns the registration object with:

Mantra.Hooks("[component name"])

As an example, consider this:


const BookViewHandlers = require("./bookviewhandlers.js);

class BooksStarter {
    async onStart( Mantra ) {
        Mantra.Hooks("books")
            .Api([{
                APIName: "addnewbook",
                APIHandler: BooksApiHandlers.AddNewBook
            }
            .Cron({
                CronConfig: "0 */5 * * * *",
                CronHandler: BooksCronHandlers.DownloadAmazonCover
            })
            .Event([ {
                EventName: "users.removed",
                EventHandler: BooksEventHandlers.OnUserRemoved
            }])
            .View([{
                Command: "showallbooks",
                Handler: BookViewsHandlers.ShowAllBooks
            }])
    }
}

In this case, a component named as books defines:

  • An API with the name addnewbook than will be handled by BooksApiHandlers.AddNewBook method.
  • A cron job for running every 5 minutes that will be handled by BooksCronHandlers.DownloadAmazonCover.
  • It defines an event handler for "user.removed" event; when this event is raised, then BooksEventHandlers.OnUserRemoved will be called.
  • A view with the route "/books/showallbooks" that will be handled by BookViewsHandlers.ShowAllBooks method (books is the name of the component and showallbooks the name of the command indicated in the hook).

Each kind of hook has its own properties, some optionals and other mandatories, and as said above, they can also be defined implicity.

To avoid to type programmatically all hooks for a component in onStart method, some of then can be automatically registered by Mantra by description according to file names definitions, as described in the following sections.


To learn by example, go to Mantra demos and components sections of Mantra site.