Diff between ViewEncapsulation.Native, ViewEncapsulation.None and ViewEncapsulation.Emulated
update
If you want styles that are added to Parent
applied to Child
you need to set ViewEncapsulation.None
in the Child
component so it doesn't prevent styles to bleed in.
Emulated
and Native
are just two different ways to prevent styles to bleed in to and out from components. None
is the only one that allows styles to cross component boundaries.
original
ViewEncapsulation.None is simple no encapsulation
ViewEncapsulation.Emulated (currently the default in Angular2)
adds attributes to component tags and child elements and manipulates the CSS (adding the attributes to the selectors) added to the page so the styles don't bleed into each other - to keep styles scoped to the components where they are added even though the styles are all added collected in the head of the page when components are loaded.ViewEncapsulation.Native creates custom elements with shadow DOM where the browsers native implementation ensures the style scoping.
If the browser doesn't support shadow DOM natively, the web-components polyfills are required to shim the behavior. This is similar toViewEncapsulation.Emulated
but the polyfills are more expensive because they polyfill lots of browser APIs even when most of them are never used. AngularsEmulated
emulation just adds the cost for what it uses and is therefore much more efficient for Angular applications.
- Native: Uses browser's native Shadow DOM. Check for browser support before enabling it.
- ShadowDom: Uses browser’s native Shadow DOM v1 for better cross-browser support and is a shared standard across the browsers. Check the difference between Shadow DOM v0 to v1.
- Emulated: Imitates behavior of Shadow DOM to scope the CSS for component and appends to the head.
- None: Neither Shadow DOM nor custom implementation, like global CSS which gets appended to the head
Angular uses ViewEncapsulation.Emulated as default encapsualtion mode.