Good evening,
as a learning project I want to build a simple "Learning Cards" App. The structure is quite simple: you have cards with questions. After a button click, you can show the correct solution. You can also click on "Question solved" to move the learning card to the absolved cards.
I am struggling to realize the "moving the learning card to the absolved" cards part. I have a "questions" array. After "onSolvedClick" the solved card gets copied to the "solved" array which is set as the new solved state.
When I click on the "Frage gelöst" (question solved) button, a new card appears in the solved questions region. The problem is: the new card is empty (without the question / answer). It would be great if someone could help me at this point! I already spent hours on this problem today.
I guess my mistake is within the App.Js code, probably in "onSolvedKlick" or "solveFragen".
Thanks a lot!
App.Js:
import React, {Component} from 'react';
import CardList from './CardList.js';
import { fragen } from './fragen';
import SearchBox from './SearchBox';
class App extends Component { // As Class to access objects
constructor () {
super();
this.state = { // State needed to change state
fragen: fragen,
solved : [] ,
searchfield: ''
}
}
onSearchChange = (event) => {
this.setState({searchfield: event.target.value});
}
onSolvedKlick = (id) => {
console.log("Klick on solved"+id);
var frage = this.state.fragen.filter(function(e) // Bei Klick auf Solved: filtere aus Ursprungsarray das Element mit gelöster iD
{
return e.id === id;
});
console.log(frage);
const newSolvedArray = this.state.solved.slice();
newSolvedArray.push(frage);
this.setState({solved: newSolvedArray});
}
render(){ // DOM rendering
const filteredFragen = this.state.fragen.filter(fragen =>{
return fragen.frage.toLowerCase().includes(this.state.searchfield.toLowerCase());
})
const solveFragen = this.state.solved;
return(
<div className='tc'>
<h1>Learning Cards</h1>
<SearchBox searchChange={this.onSearchChange}/>
<h2>Cards: To be learned!</h2>
<div>
<CardList fragen={filteredFragen} onSolvedKlick={this.onSolvedKlick}/>
<CardList fragen={solveFragen} onSolvedKlick={this.onSolvedKlick}/>
</div>
</div>
)
}
}
export default App;
CardList.js:
import React from 'react';
import Card from './Card';
const CardList = ({fragen, onSolvedKlick}) => {
const cardComponent = fragen.map( (user, i) => {
return(<Card key={i} id={fragen[i].id} frage = {fragen[i].frage} antwort = { fragen[i].antwort} onSolvedKlick = {onSolvedKlick}/>);
}
)
return (
<div>
{cardComponent}
</div>
);
}
export default CardList;
Card.js:
import React, {Component} from 'react';
import 'tachyons';
class Card extends Component {
constructor(props) {
super(props);
this.state = {
frage : props.frage,
showAnswer : false
};
}
_showAnswer = () => {
const before = this.state.showAnswer;
const after = !before;
this.setState({
showAnswer: after
});
}
render() {
return (
<div className ="fl w-50 w-25-m w-20-l pa2 bg-light-red ma3">
<div>
<h2>{this.props.frage}</h2>
{ this.state.showAnswer && (<div>{this.props.antwort}</div>) }
<p></p>
<input type="button" value="Antwort anzeigen" className ="ma2"
onClick={this._showAnswer.bind(null)}
/>
<input type="button" name="solved" value="Frage gelöst" className = "ma2 bg-light-green"
onClick={() =>this.props.onSolvedKlick(this.props.id)}
/>
</div>
</div>
);
}
}
fragen.js (Questions):
export const fragen = [
{
id: 1,
frage: 'What are trends in CPU design?',
antwort: 'Multi-core processors, SIMD support, Combination of core private and shared caches Heterogeneity, Hardware support for energy control',
topic: 'Cloud'
},
{
id: 2,
frage: 'What is typical for multi-core processors?',
antwort: 'Cache Architecture (L1 private to core, L2 private to tile), Cache Coherence',
topic: 'Cloud'
},
{
id: 3,
frage: 'What memory modes exist?',
antwort: 'Flat mode, Cache Mode, Hybrid Mode',
topic: 'Cloud'
},
{
id: 4,
frage: 'What memory modes exist?',
antwort: 'Flat mode, Cache Mode, Hybrid Mode',
topic: 'Cloud'
},
];
Try this on your onSolvedKlick
function:
onSolvedKlick = (id) => {
console.log("Klick on solved"+id);
var frage = this.state.fragen.filter((e) => e.id === id);
this.setState({solved: [...this.state.solved, frage]});
}
Try to avoid so many empty lines. Also keep your code always in english so it's easier for others to understand. I had the luck to be german too :)
Assuming that you want to move the questions from fragen
array to solved
array, here is how to do that.
onSolvedKlick = id => {
console.log("Klick on solved" + id);
var elementPos = this.state.fragen.map(function(x) {return x.id; }).indexOf(id); // Find the position of the selected item in the fragen
const currentItem = this.state.fragen.splice(elementPos,1)
const newSolvedArray = this.state.solved;
newSolvedArray.push(currentItem[0]);//splice gives an array
this.setState({ solved: newSolvedArray }, function() {console.log(this.state)});
};
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