今天来讲一下ReactDOM的几个Api
- findDOMNode
- unstable_renderSubtreeIntoContainer
- unmountComponentAtNode
findDOMNode如下：1
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31findDOMNode(
componentOrElement: Element | ?React$Component<any, any>,
): null | Element | Text {
if (__DEV__) {
let owner = (ReactCurrentOwner.current: any);
if (owner !== null && owner.stateNode !== null) {
const warnedAboutRefsInRender =
owner.stateNode._warnedAboutRefsInRender;
warningWithoutStack(
warnedAboutRefsInRender,
'%s is accessing findDOMNode inside its render(). ' +
'render() should be a pure function of props and state. It should ' +
'never access something that requires stale data from the previous ' +
'render, such as refs. Move this logic to componentDidMount and ' +
'componentDidUpdate instead.',
getComponentName(owner.type) || 'A component',
);
owner.stateNode._warnedAboutRefsInRender = true;
}
}
if (componentOrElement == null) {
return null;
}
if ((componentOrElement: any).nodeType === ELEMENT_NODE) {
return (componentOrElement: any);
}
if (__DEV__) {
return findHostInstanceWithWarning(componentOrElement, 'findDOMNode');
}
return findHostInstance(componentOrElement);
}
unmountComponentAtNode和unstable_renderSubtreeIntoContainer如下：1
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94unstable_renderSubtreeIntoContainer(
parentComponent: React$Component<any, any>,
element: React$Element<any>,
containerNode: DOMContainer,
callback: ?Function,
) {
invariant(
isValidContainer(containerNode),
'Target container is not a DOM element.',
);
invariant(
parentComponent != null && hasInstance(parentComponent),
'parentComponent must be a valid React Component',
);
return legacyRenderSubtreeIntoContainer(
parentComponent,
element,
containerNode,
false,
callback,
);
},
unmountComponentAtNode(container: DOMContainer) {
invariant(
isValidContainer(container),
'unmountComponentAtNode(...): Target container is not a DOM element.',
);
if (__DEV__) {
warningWithoutStack(
!container._reactHasBeenPassedToCreateRootDEV,
'You are calling ReactDOM.unmountComponentAtNode() on a container that was previously ' +
'passed to ReactDOM.%s(). This is not supported. Did you mean to call root.unmount()?',
enableStableConcurrentModeAPIs ? 'createRoot' : 'unstable_createRoot',
);
}
if (container._reactRootContainer) {
if (__DEV__) {
const rootEl = getReactRootElementInContainer(container);
const renderedByDifferentReact = rootEl && !getInstanceFromNode(rootEl);
warningWithoutStack(
!renderedByDifferentReact,
"unmountComponentAtNode(): The node you're attempting to unmount " +
'was rendered by another copy of React.',
);
}
// Unmount should not be batched.
unbatchedUpdates(() => {
legacyRenderSubtreeIntoContainer(null, null, container, false, () => {
container._reactRootContainer = null;
});
});
// If you call unmountComponentAtNode twice in quick succession, you'll
// get `true` twice. That's probably fine?
return true;
} else {
if (__DEV__) {
const rootEl = getReactRootElementInContainer(container);
const hasNonRootReactChild = !!(rootEl && getInstanceFromNode(rootEl));
// Check if the container itself is a React root node.
const isContainerReactRoot =
container.nodeType === ELEMENT_NODE &&
isValidContainer(container.parentNode) &&
!!container.parentNode._reactRootContainer;
warningWithoutStack(
!hasNonRootReactChild,
"unmountComponentAtNode(): The node you're attempting to unmount " +
'was rendered by React and is not a top-level container. %s',
isContainerReactRoot
? 'You may have accidentally passed in a React root node instead ' +
'of its container.'
: 'Instead, have the parent component update its state and ' +
'rerender in order to remove this component.',
);
}
return false;
}
}
export type DOMContainer =
| (Element & {
_reactRootContainer: ?(_ReactRoot | _ReactSyncRoot),
_reactHasBeenPassedToCreateRootDEV: ?boolean,
})
| (Document & {
_reactRootContainer: ?(_ReactRoot | _ReactSyncRoot),
_reactHasBeenPassedToCreateRootDEV: ?boolean,
});
