Alpine CSP `x-data` constructors

Currently Hyvä CSP is unreleased

This is a documentation preview.
Please watch the #update-notifications channel in Slack to be notified when it is available.

In regular Alpine, the component state can be initialized inline like x-data="{open: false}". This is not possible in Alpine CSP, because the attribute expressions can not be evaluated.
Non-CSP Hyvä also often uses JavaScript constructor functions declared in global scope, for example x-data="initPriceBox".
In Alpine CSP this also is not possible without registering the function explicitly as a constructor function first. The value of x-data has to refer to a function registered with Alpine.data().

<div x-data="initMyComponent">
    ...
</div>
<script>
    Alpine.data('initMyComponent', () => ({
        open: false
    }))
</script>

Be aware that the Alpine.data method likely is not yet available at the time the script is parsed, so it is a good idea to call it in a alpine:init event subscriber:

window.addEventListener(
    'alpine:init',
    () => Alpine.data('initMyComponent', () => ({
        open: false
    })),
    {once: true}
)

Hyvä uses named functions declared in global scope, so they can be proxied or wrapped, as described in Overriding JavaScript.

function initMyComponent() {
    return {
        open: false
    }
}

window.addEventListener(
    'alpine:init',
    () => Alpine.data('initMyComponent', initMyComponent),
    {once: true}
);

Merging objects

In Hyvä, Alpine components are often composed of different objects using Object.assign:

<form x-data="Object.assign(hyva.modal(), hyva.formValidation($el), {myValue: ''})">

Since JavaScript expressions are not allowed, the merging of the objects has to be moved into a constructor function.

function exampleCspComponent() {
  return Object.assign(
      hyva.modal.call(this),
      hyva.formValidation(this.$el),
      {
          myValue: ''
      }
  );
}

If one of the composed functions expects the Alpine object context, execute it with call() or assign(), as shown in the example above for hyva.modal.call(this).

Alpine CSP x-data constructors

Merging objects

Alpine CSP `x-data` constructors