Suspense, which shows the fallback on top of previous content.

Example

import Suspense from "suspense-overlay";

export default function App() {
  return <Suspense fallback="loading...">...</Suspense>;
}

With MUI Backdrop

import { alpha, Backdrop, Box, CircularProgress } from "@mui/material";
import { SuspenseOverlayCore } from "suspense-overlay";

export default function MuiBackdropSuspense({ children }) {
  return (
    <Box sx={{ position: "relative", display: "grid" }}>
      <SuspenseOverlayCore
        fallback={
          <Backdrop
            sx={{
              position: "relative",
              gridArea: "1 / 1",
              backgroundColor: (theme) =>
                alpha(theme.palette.background.paper, 0.5),
            }}
          >
            <CircularProgress />
          </Backdrop>
        }
      >
        <Box sx={{ gridArea: "1 / 1" }}>{children}</Box>
      </SuspenseOverlayCore>
    </Box>
  );
}

<Suspense>

Props

Name	Description
children	As in React.Suspense
fallback	As in React.Suspense

Optional

Name	Type	Default value	Description
Backdrop	React.ElementType	styled div	A Component that wraps and centers fallback
ChildrenWrapper	React.ElementType	contained: styled div contained=false: div	A Component that wraps children
Container	React.ElementType	contained: styled div contained=false: undefined	A Component that wraps SuspenseOverlayCore
Fallback	React.ElementType	Fallback	React Transition Group / CSSTransition
contained	boolean	true	Set false to show a fullscreen/uncontained overlay
fullscreenContainer	string | HTMLElement	document.body	A default value for container. Used also to apply different styles.
container	string | HTMLElement	fullscreenContainer	A query selector for an element or a reference to an element that the fullscreen/uncontained Backdrop & fallback is rendered to
contained	boolean	true	Set false to show a fullscreen overlay

see Fallback.tsx for more overrides and details.

<SuspenseOverlayCore>

Props

Name	Type	Default value	Description
children	React.ReactElement	-	As in React.Suspense. Must also be a valid argument for React.cloneElement and forward ref to the outermost DOM element.
fallback	React.ReactElement	-	As in React.Suspense. Must also be a valid argument for React.cloneElement.
inProp?	string	"open"	A prop name of a boolean that the fallback should use to be visible or hidden