Javascript React-componentDidUpdate()无法找到由render()方法渲染的DOM对象
编辑:我编辑了代码以添加和使用引用,而不是Javascript React-componentDidUpdate()无法找到由render()方法渲染的DOM对象,javascript,reactjs,Javascript,Reactjs,编辑:我编辑了代码以添加和使用引用,而不是document.getElementById。它没有解决问题 编辑2:所以我用mutationObserver做了一些测试,结果发现componentdiddupdate()在节点实际插入前大约100毫秒开始执行!这绝对是问题所在 但是,React文档说,componentDidUpdate()仅在render()完全执行后才会触发?我是不是遗漏了什么?如果是,什么?我只想让代码在插入render()中的所有节点后执行 编辑3:问题已被发现并解决。请参
document.getElementById
。它没有解决问题
编辑2:所以我用mutationObserver
做了一些测试,结果发现componentdiddupdate()
在节点实际插入前大约100毫秒开始执行!这绝对是问题所在
但是,React文档说,componentDidUpdate()
仅在render()
完全执行后才会触发?我是不是遗漏了什么?如果是,什么?我只想让代码在插入render()
中的所有节点后执行
编辑3:问题已被发现并解决。请参考我在下面发布的答案。感谢所有帮助过我的人
所以我正在尝试为我的网站创建一个登录对话框。我正在利用React构建对话框,并使用FirebaseUI显示内容。我的问题是,在React通过状态更改时的
render()
方法渲染DOM节点(从open:false
到open:true
)之后,componentdiddupdate()
函数无法立即找到这些DOM节点
class SignInModal extends React.Component {
constructor(props) {
super(props);
this.dialogTitle = React.createRef();
this.firebaseContainer = React.createRef();
}
state = {
open: false,
redirect: null,
preRedirectFunction: null,
};
handleClickOpen = (redirect, preRedirectFunction) => {
this.setState({
open: true,
redirect: redirect,
preRedirectFunction: preRedirectFunction,
});
}
componentDidUpdate() {
console.log("componentDidUpdate at time: ");
console.log(Date.now());
console.log("Sign in modal state: ")
console.log(this.state);
console.log("Dialog title: ")
console.log(this.dialogTitle.current);
console.log("Firebase container: ")
console.log(this.firebaseContainer.current);
/* setTimeout(function () {
var authUI = firebaseui.auth.AuthUI.getInstance();
if(authUI){
console.log("AuthUI found");
authUI.reset();
authUI.start('#firebaseui-auth-container', getUIConfig(authUI, SignInModalRendered.state.redirect,SignInModalRendered.state.preRedirectFunction));
}
else{
console.log("No AuthUI found");
startFirebaseUI("", SignInModalRendered.state.preRedirectFunction);
}
}, 200); */
}
handleClose = () => {
this.setState({
open: false,
redirect: null,
preRedirectFunction: null,
});
};
render() {
console.log("Rendering sign-in modal");
console.log("Sign in modal state: ")
console.log(this.state);
console.log("Dialog title: ")
console.log(this.dialogTitle.current);
console.log("Firebase container: ")
console.log(this.firebaseContainer.current);
return (
<div>
<Dialog
onClose={this.handleClose}
aria-labelledby="customized-dialog-title"
open={this.state.open}
>
<DialogTitle id="customized-dialog-title" ref={this.dialogTitle} onClose={this.handleClose} style={{textAlign: "center"}}>
{Date.now()}
</DialogTitle>
<DialogContent id="SignInDialogContainer">
<div id="firebaseui-auth-container" ref={this.firebaseContainer}></div>
<div id="loader">{Date.now()}</div>
</DialogContent>
</Dialog>
</div>
);
}
}
类SignInModel扩展了React.Component{
建造师(道具){
超级(道具);
this.dialogTitle=React.createRef();
this.firebaseContainer=React.createRef();
}
状态={
开:错,
重定向:null,
预重定向函数:null,
};
handleClickOpen=(重定向,预重定向函数)=>{
这是我的国家({
开放:是的,
重定向:重定向,
preRedirectFunction:preRedirectFunction,
});
}
componentDidUpdate(){
log(“componentdiddupdateat time:”);
console.log(Date.now());
日志(“登录模式状态:”)
console.log(this.state);
日志(“对话框标题:”)
console.log(this.dialogTitle.current);
日志(“Firebase容器:”)
log(this.firebaseContainer.current);
/*setTimeout(函数(){
var authUI=firebaseui.auth.authUI.getInstance();
if(authUI){
console.log(“AuthUI-find”);
reset();
authUI.start('#firebaseui auth container',getUIConfig(authUI,signnmodalrendered.state.redirect,signnmodalrendered.state.preRedirectFunction));
}
否则{
log(“未找到AuthUI”);
startFirebaseUI(“,SignInModalRendered.state.preRedirectFunction”);
}
}, 200); */
}
handleClose=()=>{
这是我的国家({
开:错,
重定向:null,
预重定向函数:null,
});
};
render(){
console.log(“呈现登录模式”);
日志(“登录模式状态:”)
console.log(this.state);
日志(“对话框标题:”)
console.log(this.dialogTitle.current);
日志(“Firebase容器:”)
log(this.firebaseContainer.current);
返回(
{Date.now()}
{Date.now()}
);
}
}
执行此代码时,代码在authUI.start(“#firebaseui auth container”…
行失败,因为它找不到DOM节点
对于编辑的代码,我只是试图获取componentdiddupdate()
中的控制台日志,以便能够找到对话框标题和Firebase容器DOM节点。它们仍然返回null
但是,DOM中的Date.now()
函数和componentdiddupdate()
函数(如上图所示)的输出显示,componentdiddupdate()
中的代码是在呈现DOM后2毫秒执行的。那么为什么componentdiddupdate()中的代码行是
找不到它吗
我发现componentdiddupdate()
在节点渲染完成前大约100毫秒执行。为什么会这样?在节点渲染完成后如何让代码执行
其他信息:我尝试将有问题的代码块以200毫秒的延迟放入
setTimeout
函数中,它运行得非常好。但我不想使用此解决方法,我想了解发生了什么。在构造函数中创建引用。例如:this.refName=React.createRef();
将ref指定为组件中的道具
使用this.refName.current
class SignInModal extends React.Component {
constructor (props) {
super(props);
this.customizedDialogTitle = React.createRef();
this.signInDialogContainer = React.createRef();
this.firebaseuiAuthContainer = React.createRef();
this.loader = React.createRef();
this.state = {
open: false,
redirect: null,
preRedirectFunction: null,
}
}
handleClickOpen = (redirect, preRedirectFunction) => {
this.setState({
open: true,
redirect: redirect,
preRedirectFunction: preRedirectFunction,
});
}
componentDidUpdate() {
console.log("componentDidUpdate at time: ");
console.log(Date.now());
console.log("Sign in modal state: ")
console.log(this.state);
console.log("Dialog title: ")
console.log(this.customizedDialogTitle.current);
console.log("Firebase container: ")
console.log(this.firebaseuiAuthContainer.current);
var authUI = firebaseui.auth.AuthUI.getInstance();
if(authUI){
console.log("AuthUI found");
authUI.reset();
authUI.start('#firebaseuiAuthContainer', getUIConfig(authUI, this.state.redirect,this.state.preRedirectFunction));
}
else{
console.log("No AuthUI found");
startFirebaseUI("", this.state.preRedirectFunction);
}
}
handleClose = () => {
this.setState({
open: false,
redirect: null,
preRedirectFunction: null,
});
};
render() {
console.log("Rendering sign-in modal");
console.log("Sign in modal state: ")
console.log(this.state);
console.log("Dialog title: ")
console.log(this.customizedDialogTitle.current);
console.log("Firebase container: ")
console.log(this.firebaseuiAuthContainer.current);
return (
<div>
<Dialog
onClose={this.handleClose}
aria-labelledby="customized-dialog-title"
open={this.state.open}
>
<DialogTitle ref={this.customizedDialogTitle} id="customized-dialog-title" onClose={this.handleClose} style={{textAlign: "center"}}>
{Date.now()}
</DialogTitle>
<DialogContent ref={this.signInDialogContainer}>
<div ref={this.firebaseuiAuthContainer}></div>
<div ref={this.loader}>{Date.now()}</div>
</DialogContent>
</Dialog>
</div>
);
}
}
类SignInModel扩展了React.Component{
建造师(道具){
超级(道具);
this.customizedDialogTitle=React.createRef();
this.signInDialogContainer=React.createRef();
this.firebaseuiAuthContainer=React.createRef();
this.loader=React.createRef();
此.state={
开:错,
重定向:null,
预重定向函数:null,
}
}
handleClickOpen=(重定向,预重定向函数)=>{
这是我的国家({
开放:是的,
重定向:重定向,
preRedirectFunction:preRedirectFunction,
});
}
componentDidUpdate(){
log(“componentdiddupdateat time:”);
console.log(Date.now());
日志(“登录模式状态:”)
console.log(this.state);
日志(“对话框标题:”)
log(this.customizedDialogTitle.current);
日志(“Firebase容器:”)
log(this.firebaseuauthcontainer.current);
var authUI=firebaseui.auth.authUI.getInstance();
if(authUI){
console.log(“AuthUI-find”);
reset();
authUI.start('#firebaseuauthcontainer',getUIConfig(authUI,this.state.redirect,this.state.preRedirectFunction));
}
否则{
log(“未找到AuthUI”);
startFirebaseUI(“,this.state.preRedirectFunction”);
}
}
handleC
class FirebaseContainer extends React.Component {
constructor(props){
super(props);
console.log("Passed props: ");
console.log(props);
this.firebaseContainer = React.createRef();
}
state = this.props.parentState;
componentDidMount() {
console.log("componentDidMount at time: ");
console.log(Date.now());
/* console.log("Sign in modal state: ")
console.log(this.state); */
console.log("Firebase container: ")
console.log(this.firebaseContainer.current);
var authUI = firebaseui.auth.AuthUI.getInstance();
if(authUI){
console.log("AuthUI found");
authUI.reset();
authUI.start('#firebaseui-auth-container', getUIConfig(authUI, this.state.redirect,this.state.preRedirectFunction));
}
else{
console.log("No AuthUI found");
startFirebaseUI("", this.state.preRedirectFunction);
}
}
render(){
console.log("Rendering Firebase container");
console.log("Firebase container state: ")
console.log(this.state);
console.log("Dialog title: ")
console.log(document.getElementById('customized-dialog-title'));
console.log("Firebase container: ")
console.log(document.getElementById('firebaseui-auth-container'));
return(
<div id="firebaseui-auth-container" ref={this.firebaseContainer}></div>
);
}
}
class SignInModal extends React.Component {
constructor(props) {
super(props);
this.dialogTitle = React.createRef();
}
state = {
open: false,
redirect: null,
preRedirectFunction: null,
};
handleClickOpen = (redirect, preRedirectFunction) => {
this.setState({
open: true,
redirect: redirect,
preRedirectFunction: preRedirectFunction,
});
}
handleClose = () => {
this.setState({
open: false,
redirect: null,
preRedirectFunction: null,
});
};
render() {
console.log("Rendering sign-in modal");
console.log("Sign in modal state: ")
console.log(this.state);
return (
<Dialog ref={this.dialogTitle}
onClose={this.handleClose}
aria-labelledby="customized-dialog-title"
open={this.state.open}
>
<DialogTitle id="customized-dialog-title" onClose={this.handleClose} style={{textAlign: "center"}}>
Please sign in
</DialogTitle>
<DialogContent id="SignInDialogContainer">
<FirebaseContainer parentState={this.state}/>
<div id="loader">{Date.now()}</div>
</DialogContent>
</Dialog>
);
}
}