reactjs - ReactNative: undefined is not an object (this.state.listAccounts) - 


class widgets extends component {     constructor(props){         super(props);         this.state = {             accesstoken: "",             listaccounts:[],         }     }     componentwillmount(){         this.setstate({listaccounts: this.loadaccountsdata()})     }     loadaccountsdata(){          //return data server     }     render() {         return (                 <content>                     {this.state.listaccounts.map( (account) => <account accountdata={account} />)}                 </content>         )     } }

above blue print of code. unabele access state in render? error: undefined not object (evaluating 'this.state.listaccounts.map')

you setting state on async request. need wait till response comes set state.

class widgets extends component {     constructor(props){         super(props);         this.state = {             accesstoken: "",             listaccounts:[],         }     }     componentwillmount(){         this.loadaccountsdata();     }     loadaccountsdata(){          somerequest().then( (response) => {              this.setstate({listaccounts: response});              // or whatever data accounts          });     }     render() {         return (                 <content>                     {this.state.listaccounts.map( (account) => <account accountdata={account} />)}                 </content>         )     } }

Comments

Post a Comment

Popular posts from this blog

aws api gateway - SerializationException in posting new Records via Dynamodb Proxy Service in API -

i getting "__type": "com.amazon.coral.service#serializationexception" as reply in postman & in test console in api gateway trying post record directly dynamodb using api proxy services.. referring aws article - https://aws.amazon.com/blogs/compute/using-amazon-api-gateway-as-a-proxy-for-dynamodb/ here's mapping { "tablename": "tablenamegoeshere", "item": { "id" : "$context.requestid" "eventname" : "$input.path('$.eventname')", "timestamp" : $input.path('$.timestamp'), "answers": "$util.parsejson($input.path('$.answers'))" } } update: did asked ... , worked if try add array of json objects gives me above same error - here's trying now. please - couldnt find on google well #set($inputroot = $input.path('$')) { "tablename": "answer", "item": {
Read more

asp.net - Problems sending emails from forum -

i have been redesigning site has message board, has been written guy looked after site. it has few problems , written in .asp , uses .mdb files database. you can see whole thing here . feel free post if helps, test thing have set using original files , new database. the basic problem when posts message, supposed email sent them, have posted it. when replies, originator supposed message, replier has been posted. i’d have thought @ point in process there should script/file in postmessage.asp? the postmessage.asp page below. <% option explicit %> <!-- #include virtual="common/adovbs.inc" --> <html> <head> <meta http-equiv="content-type" content="text/html; charset=windows-1252"> <meta name="generator" content="microsoft frontpage 4.0"> <meta name="progid" content="frontpage.editor.document"> <title>new page 2</title> <base target="_self"
Read more