javascript - Using React's shouldComponentUpdate with Immutable.js cursors -


i'm having trouble figuring out how short circuit rendering branch of tree of react components using immutable.js cursors.

take following example:

import react 'react'; import immutable 'immutable'; import cursor 'immutable/contrib/cursor';  let data = immutable.fromjs({   things: [     {title: '', key: 1},     {title: '', key: 2}   ] });  class thing extends react.component {   shouldcomponentupdate(nextprops) {     return this.props.thing.deref() !== nextprops.thing.deref();   }    handlechangetitle(e) {     this.props.thing.set('title', e.target.value);   }        render() {     return <div>       <input value={this.props.thing.get('title')}          onchange={this.handlechangetitle.bind(this)} />     </div>;   } }  class container extends react.component {   render() {     const cursor = cursor.from(this.props.data, 'things', newthings => {       data.set('things', newthings);       rendercontainer();     });      const things = cursor.map(thing => (       <thing thing={thing} key={thing.get('key')} />     ));      return <div>       {things}     </div>;   } }  const rendercontainer = () => {   react.render(<container data={data} />, document.getelementbyid('somediv')); };

say change first thing's title. first thing render new title , second thing not re-render due shouldcomponentupdate. however, if change second thing's title, first thing's title go '' since second thing's cursor still pointing @ older version of root data.

we update cursors on each render of container ones don't render due shouldcomponentupdate don't new cursor updated root data. way can see keeping cursors date remove shouldcomponentupdate in thing component in example.

is there way change example use shouldcomponentupdate using fast referential equality checks keep cursors updated?

or, if that's not possible, provide overview of how work cursors + react components , rendering components updated data?

i updated code, see comments inline: 

class thing extends react.component {   shouldcomponentupdate(nextprops) {     return this.props.thing.deref() !== nextprops.thing.deref();   }    handlechangetitle(e) {     // trigger method on container handle update     this.props.ontitlechange(this.props.thing.get('key'), e.target.value);   }        render() {     return <div>       <input value={this.props.thing.get('title')}          onchange={this.handlechangetitle.bind(this)} />     </div>;   } }  class container extends react.component {   constructor() {     super();     this.initcursor();   }    initcursor() {     // store cursor instance variable access methods     this.cursor = cursor.from(data, 'things', newthings => {       data = data.set('things', newthings);       // trigger re-render       this.forceupdate();     });   }    render() {     const things = this.cursor.map(thing => (       <thing thing={thing} key={thing.get('key')} ontitlechange={this.ontitlechange.bind(this)} />     ));      return <div>       {things}     </div>;   }    ontitlechange(key, title){     // update cursor store changed things     this.cursor = this.cursor.update(x => {       // update single thing       var thing = x.get(key - 1).set('title', title);       // return updated things       return x.set(key - 1,thing);     });   } }  const rendercontainer = () => {   react.render(<container data={data} />, document.getelementbyid('somediv')); };

-

Comments

Post a Comment

Popular posts from this blog

apache - PHP Soap issue while content length is larger -

we have developed soap based webservice post data third party webservice. accepts 4 params. in 1 of parameters accepts xml string no size limit restriction put in place. the webservice works fine in local environment running on php 5.2 , apache2. works content length long 10 mb. in staging server running nginx , php fpm.we have updated max post size , max upload filesize in php.ini , client_max_body param in nginx.conf allow upto 50 mb. but webservice client keeps on loading in staging environment. gives 502 timeout , gives soap error. can me understand issue here?
Read more

asynchronous - Python asyncio task got bad yield -

i confused how play around asyncio module in python 3.4. have searching api search engine, , want each search request run either parallel, or asynchronously, don't have wait 1 search finish start another. here high-level searching api build objects raw search results. search engine using kind of asyncio mechanism, won't bother that. # no asyncio module used here class search(object): ... self.s = some_search_engine() ... def searching(self, *args, **kwargs): ret = {} # raw searching according args , kwargs , build wrapped results ... return ret to try async requests, wrote following test case test how can interact stuff asyncio module. # here testing script @asyncio.coroutine def handle(f, *args, **kwargs): r = yield f(*args, **kwargs) return r s = search() loop = asyncio.get_event_loop() loop.run_until_complete(handle(s.searching, arg1, arg2, ...)) loop.close() by running pytest, return runtimeerror: task got bad yield : {results s...
Read more

javascript - Complete OpenIDConnect auth when requesting via Ajax -

the normal openidconnect server works like: you go a.com/secure-resource you 302 server your browser handles , sends identity server you login there it sends a.com via post you logged in on a.com , a.com/secure-resource on browser. however have scenario i'm trying solve need help. the user logged in on idserver the user logged in on a.com the user not logged in on b.com we need send ajax call web server b.com (from domain a.com ) b.com configured use openidconnect. but because request b.com via ajax, user cannot redirected idserver. (all in response 302 ) we can go ahead , handle 302 via ajax (i'm still not sure whether work, security-wise). but is there scenario in identityserver/openidconnect designed these situations? with identityserver in scenario setup server b.com use bearer token authentication, need use access token provided a.com in headers of ajax call $.ajax({ url: 'http://b.com', headers: { ...
Read more