Я разрабатываю приложение IPFS-Ethereum с использованием React JS, где я буду загружать файл XML и анализировать его. У меня проблема с отображением проанализированных данных в виде массива в таблице. Показывает только последний элемент в массиве.
This is the code used for parsing, in console it is showing the two data in the console which is parsed. But in Table it is showing only the last element. I tried using this this.liItem[i]/this.liItem[0] but it is throwing undefined error.
var request = new Request(`https://gateway.ipfs.io/ipfs/${this.state.ipfsHash}`);
fetch(request).then((results) => {
// results returns XML. lets cast this to a string, then create
// a new DOM object out of it!
results
.text()
.then((str) => {
this.state.responseDoc = new DOMParser().parseFromString(str, 'application/xml');
console.log(this.state.responseDoc);
this.state.listItem = this.state.responseDoc.getElementsByTagName('Name');
// console.log(listItem);
for (this.i = 0; this.i < this.state.listItem.length; this.i++) {
this.liItem = this.state.responseDoc.getElementsByTagName('Name')[this.i].textContent;
this.setState({
liItem: this.state.liItem
});
console.log(this.liItem);
}
})
Это строка {this.liItem}, используемая в таблице для отображения данных массива. ( ссылка на картинку )
Это мой файл App.js.
import {Table, Grid, Button, Form} из'act-bootstrap ';
импортировать React, {Component} из 'response';
import './App.css';
импортировать web3 из './web3';
импортировать ipfs из './ipfs';
импортировать хранилище из './storehash';
class App extends Component {
state = {
ipfsHash:null,
buffer:'',
ethAddress:'',
blockNumber:'',
transactionHash:'',
gasUsed:'',
txReceipt: '',
responseDoc:'',
listItem:'',
i:'',
liItem:[]
};
captureFile =(event) => {
event.stopPropagation()
event.preventDefault()
const file = event.target.files[0]
let reader = new window.FileReader()
reader.readAsArrayBuffer(file)
reader.onloadend = () => this.convertToBuffer(reader)
};
convertToBuffer = async(reader) => {
//file is converted to a buffer to prepare for uploading to IPFS
const buffer = await Buffer.from(reader.result);
//set this buffer -using es6 syntax
this.setState({buffer});
};
onClick = async () => {
try{
this.setState({blockNumber:"waiting.."});
this.setState({gasUsed:"waiting..."});
// get Transaction Receipt in console on click
// See: https://web3js.readthedocs.io/en/1.0/web3- eth.html#gettransactionreceipt
await web3.eth.getTransactionReceipt(this.state.transactionHash, (err, txReceipt)=>{
console.log(err,txReceipt);
this.setState({txReceipt});
}); //await for getTransactionReceipt
await this.setState({blockNumber: this.state.txReceipt.blockNumber});
await this.setState({gasUsed: this.state.txReceipt.gasUsed});
} //try
catch(error){
console.log(error);
} //catch
var request = new Request(`https://gateway.ipfs.io/ipfs/${this.state.ipfsHash}`);
fetch(request).then((results) => {
// results returns XML. lets cast this to a string, then create
// a new DOM object out of it!
results
.text()
.then(( str ) => {
this.state.responseDoc = new DOMParser().parseFromString(str, 'application/xml');
console.log(this.state.responseDoc);
this.state.listItem = this.state.responseDoc.getElementsByTagName('Name');
// console.log(listItem);
for (this.i=0; this.i<this.state.listItem.length; this.i++){
this.liItem = this.state.responseDoc.getElementsByTagName('Name')[this.i].textContent;
this.setState({liItem: this.state.liItem});
console.log(this.liItem);
}
})
});
} //onClick
onSubmit = async (event) => {
event.preventDefault();
//bring in user's metamask account address
const accounts = await web3.eth.getAccounts();
console.log('Sending from Metamask account: ' + accounts[0]);
//obtain contract address from storehash.js
const ethAddress= await storehash.options.address;
this.setState({ethAddress});
//save document to IPFS,return its hash#, and set hash# to state
//https://github.com/ipfs/interface-ipfs-core/blob/master/SPEC/FILES.md#add
await ipfs.add(this.state.buffer, (err, ipfsHash) => {
console.log(err,ipfsHash);
//setState by setting ipfsHash to ipfsHash[0].hash
this.setState({ ipfsHash:ipfsHash[0].hash });
// call Ethereum contract method "sendHash" and .send IPFS hash to etheruem contract
//return the transaction hash from the ethereum contract
//see, this https://web3js.readthedocs.io/en/1.0/web3-eth-contract.html#methods-mymethod-send
storehash.methods.sendHash(this.state.ipfsHash).send({
from: accounts[0]
}, (error, transactionHash) => {
console.log(transactionHash);
this.setState({transactionHash});
}
); //storehash
}) //await ipfs.add
}; //onSubmit
render() {
return (
<div className="App">
<header className="App-header">
<h1>
{" "}
Ethereum and InterPlanetary File System(IPFS) with Create React App
</h1>
</header>
<hr />
<Grid>
<h3> Choose file to send to IPFS </h3>
<Form onSubmit={this.onSubmit}>
<input type="file" onChange={this.captureFile} />
<Button bsStyle="primary" type="submit">
Send it
</Button>
</Form>
<br />
<img
src={`https://ipfs.io/ipfs/${this.state.ipfsHash}`}
alt=""
style={{ height: 200 }}
/>
<hr />
<Button onClick={this.onClick}> Get Transaction Receipt </Button>
<Table bordered responsive>
<thead>
<tr>
<th>Tx Receipt Category</th>
<th>Values</th>
</tr>
</thead>
<tbody>
<tr>
<td>IPFS Hash # stored on Eth Contract</td>
<td>{this.state.ipfsHash}</td>
</tr>
<tr>
<td>Ethereum Contract Address</td>
<td>{this.state.ethAddress}</td>
</tr>
<tr>
<td>Tx Hash # </td>
<td>{this.state.transactionHash}</td>
</tr>
<tr>
<td>Block Number # </td>
<td>{this.state.blockNumber}</td>
</tr>
<tr>
<td>Gas Used</td>
<td>{this.state.gasUsed}</td>
</tr>
<tr>
<td>XML</td>
<td>{this.liItem}</td>
</tr>
</tbody>
</Table>
</Grid>
</div>
);
//render
}
}
export default App;
Я надеюсь, что вы, люди, поймете мой вопрос и дадите мне решение.
Спасибо