2.0.4 • Public • Published

Visual Controller for Svelte

NOTE: Version 2.0.2 works with Svelte 4. Product is not changed, just the dependency. If you need version 3 of Svelte, use version 2.0.1 of this library.

version license

Tool for building a micro-frontends(MFE) based on Svelte components - Start multiple Svelte applications in the same HTML page and control them.

Install visual controller:

npm i @peter.naydenov/visual-controller-for-svelte

Initialization process:

import notice from '@peter.naydenov/notice' // event emitter by your personal choice.
import VisualController from '@peter.naydenov/visual-controller-for-svelte'

      eBus = notice ()
    , dependencies = { eBus }  // Provide everything that should be exposed to components 
    , html = new VisualController ( dependencies ) 
// Ready for use...

Let's show something on the screen:

// Let's have svelte component 'Hello' with prop 'greeting'

html.publish ( Hello, {greeting:'Hi'}, 'app' )
//arguments are: ( component, props, containerID )

Inside of the Components

Note: If your component should be displayed only, that section can be skipped.

All provided libraries during visualController initialization are available if you export variable with name dependencies. Export also setupUpdates if you need to manipulate component

let msg = 'Vite + Svelte'
export let dependencies, setupUpdates;
const { eBus } = dependencies

setupUpdates ({   // Provides to visualContoller method 'changeMessage' 
          changeMessage (update) {
                  msg = update

The external call will look like this:

html.getApp ( 'app' ).changeMessage ( 'New message content' )

Visual Controller Methods

  publish : 'Render svelte app in container. Associate app instance with the container.'
, getApp  : 'Returns app instance by container name'
, destroy : 'Destroy app by using container name '
, has     : 'Checks if app with specific "id" was published'

VisualController.publish ()

Publish a svelte app.

html.publish ( component, props, containerID )
  • component: object. Svelte component
  • props: object. Svelte components props
  • containerID: string. Id of the container where svelte-app will live.
  • returns: Promise. Update methods library if defined. Else will return a empty object;


 let html = new VisualController ();
 html.publish ( Hi, { greeting: 'hi'}, 'app' )

Render component 'Hi' with prop 'greeting' and render it in html element with id "app".

VisualController.getApp ()

Returns the library of functions provided from method setupUpdates. If svelte-app never called setupUpdates, result will be an empty object.

 let controls = html.getApp ( containerID )
  • containerID: string. Id of the container.


      id = 'videoControls'
    , controls = html.getApp ( id )
    // if app with 'id' doesn't exist -> returns false, 
    // if app exists and 'setupUpdates' was not used -> returns {}
    // in our case -> returns { changeMessage:f }
if ( !controls )   console.error ( `App for id:"${id}" is not available` )
else {
        if ( controls.changeMessage )   controls.changeMessage ('new title') 

If visual controller(html) has a svelte app associated with this name will return it. Otherwise will return false.

VisualController.destroy ()

Will destroy svelte app associated with this container name and container will become empty. Function will return 'true' on success and 'false' on failure. Function will not delete content of provided container if there is no svelte app associated with it.

html.destroy ( containerID )
  • containerID: string. Id name.


Visual Controller has versions for few other front-end frameworks:

Release History

2.0.4 ( 2023-10-31)

  • [x] Dependency update. Ask-for-promise@1.5.0;

2.0.2 ( 2023-06-25)

  • [x] Using svelte version 4.x.x;
  • [x] No other changes in the product;

2.0.1 ( 2023-06-06)

  • [x] Works with vite version 4.x.x;

2.0.0 ( 2022-11-22)

  • [x] Full rewrite of the library;
  • [x] Method 'has' was added;
  • [x] Support for SSR hydration;
  • [x] Method 'publish' returns a promise;
  • [x] Testing;
  • [x] Documentation update;

1.0.0 (2021-05-11)

  • [x] Code;
  • [x] Documentation;

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npm i @peter.naydenov/visual-controller-for-svelte3

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