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mirror of https://github.com/naturalcrit/homebrewery.git synced 2025-12-26 05:12:39 +00:00
Files
homebrewery/client/homebrew/brewRenderer/brewRenderer.jsx
Trevor Buckner aa065fa4d8 Do not Server-Side Render the markdown (#1177)
1) Rendering is fast enough on the client we don't need to provide SSR for the brew contents.
2) This leaves our server open to REDOS attacks if users create ridiculously long single lines of text. The Markdown parser slows down with exponential time which becomes noticeable at 10,000+ characters in one line, and at 200,000+ characters will stall the server and eventually crash.
3) This now shows a nice loading circle for the half-second that a page takes to render. If a user tries to load a huge line of text the loading circle will be there instead of a blank white page.
2021-01-02 16:54:50 -05:00

187 lines
5.3 KiB
JavaScript

require('./brewRenderer.less');
const React = require('react');
const createClass = require('create-react-class');
const _ = require('lodash');
const cx = require('classnames');
const Markdown = require('naturalcrit/markdown.js');
const ErrorBar = require('./errorBar/errorBar.jsx');
//TODO: move to the brew renderer
const RenderWarnings = require('homebrewery/renderWarnings/renderWarnings.jsx');
const NotificationPopup = require('./notificationPopup/notificationPopup.jsx');
const Frame = require('react-frame-component').default;
const PAGE_HEIGHT = 1056;
const PPR_THRESHOLD = 50;
const BrewRenderer = createClass({
getDefaultProps : function() {
return {
text : '',
errors : []
};
},
getInitialState : function() {
const pages = this.props.text.split('\\page');
return {
viewablePageNumber : 0,
height : 0,
isMounted : false,
pages : pages,
usePPR : pages.length >= PPR_THRESHOLD,
visibility : 'hidden',
initialContent : `<!DOCTYPE html><html><head>
<link href="//netdna.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet" />
<link href="//fonts.googleapis.com/css?family=Open+Sans:400,300,600,700" rel="stylesheet" type="text/css" />
<link href='/homebrew/bundle.css' rel='stylesheet' />
<base target=_blank>
</head><body style='overflow: hidden'><div></div></body></html>`
};
},
height : 0,
lastRender : <div></div>,
componentWillUnmount : function() {
window.removeEventListener('resize', this.updateSize);
},
componentWillReceiveProps : function(nextProps) {
const pages = nextProps.text.split('\\page');
this.setState({
pages : pages,
usePPR : pages.length >= PPR_THRESHOLD
});
},
updateSize : function() {
this.setState({
height : this.refs.main.parentNode.clientHeight,
});
},
handleScroll : function(e){
const target = e.target;
this.setState((prevState)=>({
viewablePageNumber : Math.floor(target.scrollTop / target.scrollHeight * prevState.pages.length)
}));
},
shouldRender : function(pageText, index){
if(!this.state.isMounted) return false;
const viewIndex = this.state.viewablePageNumber;
if(index == viewIndex - 3) return true;
if(index == viewIndex - 2) return true;
if(index == viewIndex - 1) return true;
if(index == viewIndex) return true;
if(index == viewIndex + 1) return true;
if(index == viewIndex + 2) return true;
if(index == viewIndex + 3) return true;
//Check for style tages
if(pageText.indexOf('<style>') !== -1) return true;
return false;
},
renderPageInfo : function(){
return <div className='pageInfo' ref='main'>
{this.state.viewablePageNumber + 1} / {this.state.pages.length}
</div>;
},
renderPPRmsg : function(){
if(!this.state.usePPR) return;
return <div className='ppr_msg'>
Partial Page Renderer enabled, because your brew is so large. May effect rendering.
</div>;
},
renderDummyPage : function(index){
return <div className='phb' id={`p${index + 1}`} key={index}>
<i className='fa fa-spinner fa-spin' />
</div>;
},
renderPage : function(pageText, index){
return <div className='phb' id={`p${index + 1}`} dangerouslySetInnerHTML={{ __html: Markdown.render(pageText) }} key={index} />;
},
renderPages : function(){
if(this.state.usePPR){
return _.map(this.state.pages, (page, index)=>{
if(this.shouldRender(page, index) && typeof window !== 'undefined'){
return this.renderPage(page, index);
} else {
return this.renderDummyPage(index);
}
});
}
if(this.props.errors && this.props.errors.length) return this.lastRender;
this.lastRender = _.map(this.state.pages, (page, index)=>{
if(typeof window !== 'undefined') {
return this.renderPage(page, index);
} else {
return this.renderDummyPage(index);
}
});
return this.lastRender;
},
frameDidMount : function(){ //This triggers when iFrame finishes internal "componentDidMount"
setTimeout(()=>{ //We still see a flicker where the style isn't applied yet, so wait 100ms before showing iFrame
this.updateSize();
window.addEventListener('resize', this.updateSize);
this.renderPages(); //Make sure page is renderable before showing
this.setState({
isMounted : true,
visibility : 'visible'
});
}, 100);
},
render : function(){
//render in iFrame so broken code doesn't crash the site.
//Also render dummy page while iframe is mounting.
return (
<React.Fragment>
{!this.state.isMounted
? <div className='brewRenderer' onScroll={this.handleScroll}>
<div className='pages' ref='pages'>
{this.renderDummyPage(1)}
</div>
</div>
: null}
<Frame initialContent={this.state.initialContent} style={{ width: '100%', height: '100%', visibility: this.state.visibility }} contentDidMount={this.frameDidMount}>
<div className='brewRenderer'
onScroll={this.handleScroll}
style={{ height: this.state.height }}>
<ErrorBar errors={this.props.errors} />
<div className='popups'>
<RenderWarnings />
<NotificationPopup />
</div>
<div className='pages' ref='pages'>
{this.state.isMounted
? this.renderPages()
: null}
</div>
</div>
</Frame>
{this.renderPageInfo()}
{this.renderPPRmsg()}
</React.Fragment>
);
}
});
module.exports = BrewRenderer;