This is an overhaul of custom elements in Svelte. Instead of compiling to a custom element class, the Svelte component class is mostly preserved as-is. Instead a wrapper is introduced which wraps a Svelte component constructor and returns a HTML element constructor. This has a couple of advantages:
- component can be used both as a custom element as well as a regular component. This allows creating one wrapper custom element and using regular Svelte components inside. Fixes#3594, fixes#3128, fixes#4274, fixes#5486, fixes#3422, fixes#2969, helps with https://github.com/sveltejs/kit/issues/4502
- all components are compiled with injected styles (inlined through Javascript), fixes#4274
- the wrapper instantiates the component in `connectedCallback` and disconnects it in `disconnectedCallback` (but only after one tick, because this could be a element move). Mount/destroy works as expected inside, fixes#5989, fixes#8191
- the wrapper forwards `addEventListener` calls to `component.$on`, which allows to listen to custom events, fixes#3119, closes#4142
- some things are hard to auto-configure, like attribute hyphen preferences or whether or not setting a property should reflect back to the attribute. This is why `<svelte:options customElement={..}>` can also take an object to modify such aspects. This option allows to specify whether setting a prop should be reflected back to the attribute (default `false`), what to use when converting the property to the attribute value and vice versa (through `type`, default `String`, or when `export let prop = false` then `Boolean`), and what the corresponding attribute for the property is (`attribute`, default lowercased prop name). These options are heavily inspired by lit: https://lit.dev/docs/components/properties. Closes#7638, fixes#5705
- adds a `shadowdom` option to control whether or not encapsulate the custom element. Closes#4330, closes#1748
Breaking changes:
- Wrapped Svelte component now stays as a regular Svelte component (invokeing it like before with `new Component({ target: ..})` won't create a custom element). Its custom element constructor is now a static property named `element` on the class (`Component.element`) and should be regularly invoked through setting it in the html.
- The timing of mount/destroy/update is different. Mount/destroy/updating a prop all happen after a tick, so `shadowRoot.innerHTML` won't immediately reflect the change (Lit does this too). If you rely on it, you need to await a promise
Closes#3310
---------
Co-authored-by: Ben McCann <322311+benmccann@users.noreply.github.com>
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
* Move @html tutorial to end
* move debug and html tag into one section
* rename
---------
Co-authored-by: Rémi Marche <35939574+Marr11317@users.noreply.github.com>
Co-authored-by: Simon H <5968653+dummdidumm@users.noreply.github.com>
Co-authored-by: Simon Holthausen <simon.holthausen@vercel.com>
Co-authored-by: Tan Li Hau <tanhauhau@users.noreply.github.com>
Co-authored-by: Ben McCann <322311+benmccann@users.noreply.github.com>
Co-authored-by: Gabor Szabo <gabor@szabgab.com>
Co-authored-by: gtmnayan <50981692+gtm-nayan@users.noreply.github.com>
* add more examples on the spring store API docs
* Update site/content/docs/03-run-time.md
Co-authored-by: Ignatius Bagus <ignatius.mbs@gmail.com>
* Update site/content/docs/03-run-time.md
Co-authored-by: Ignatius Bagus <ignatius.mbs@gmail.com>
Co-authored-by: Ignatius Bagus <ignatius.mbs@gmail.com>
Simon H
Cavit Ertuğrul Sırt
Dave Lunny
Henrik Giesel
Invader Zim
Mike Randazzo
brunnerh
Rémi Marche
Jhorman Ruswel ㅠㅠ
Josh
gaac510
Daniel Huang
Sanguansak Petchmeesri
Janosh Riebesell
Josh Soref
Ben McCann
schelv
孟世博
Simon Dao
Heechul Ryu
Rich Harris
Stephanie Tuerk
Hyunseung Lee
tanhauhau
Tan Li Hau
Thad Guidry
Jan
gtmnayan
josh-brainbox
Yuichiro Yamashita
Isabel Leccese
Nick Cummings
opensas
NazarLazarchuk
Arad Aral
Austin Walela
Yongwook Choi
Maxi Ferreira
Ignatius Bagus
Conduitry
Dustin Wyatt