Static tags

[Rich-Harris]

Sometimes you know for a fact that some data isn't going to change. In those situations there's no point adding update logic.

Ractive (and I think Polymer, maybe?) allows component authors to use square brackets to denote that some data is fixed:

<p>{{willChange}}</p>
<p>[[wontChange]]</p>

Gets a bit confusing when blocks are involved — need to have a clear idea about what should happen if you have curlies inside square brackets and vice versa.

[PaulBGD]

I actually think this would be more useful in passing attributes, because I don't think there's many use cases where the data doesn't change from within a component.

[TehShrike]

This would be difficult to resolve with a potential syntax change to drop double-curlies for single-curlies. I like the idea in theory - though I feel like I'd rather note it in the exported object instead of the template.

export default {
  data() {
    return {
      willChange: 1,
      wontchange: 2
    }
  }
  static: [ 'wontChange' ]
}

[tivac]

I would love to see this, given my predilection for using modular-css to style things. I like the template syntax idea for its ease-of-use but the component-level marking approach from @TehShrike is probably clearer overall.

[Rich-Harris]

This is yet another issue that is basically a non-issue post-RFC-1:

<script>
  export let willChange = 1;
  const wontChange = 2;
</script>

<p>{willChange}</p>
<p>{wontChange}</p>

The same applies to modular CSS approaches:

<script>
  import styles from './styles.css';
</script>

<div class={styles.foo}>
  ...
</div>

[Rich-Harris]

(To be clear, let wontChange = 2 would also not get the reactivity treatment, unless there was a post-declaration assignment, because it's not exported. Just using const to illustrate the point)

[Conduitry]

As noted above, this is handled in v3 by keeping track of whether there are any reassignments to a variable. Closing.