React Unable to Access Json Resposne from API - json

In my website on login,i get a confirmation and a token which i need to store and pass as a property throughout all the pages.I am able to receive the token,but i am unable to store the value for the token and store it as a state value.
Here is the code i have tried so far.
import React from 'react'
import ReactDOM from 'react-dom'
import {Login_Submit_style,Login_button_style,Login_text_field_style,
password_style,para_login_style} from './style'
import Supers from 'superagent'
class Login extends React.Component
{
constructor(props)
{
super(props);
this.state={username:'',password:''}
this.Login_data_password=this.Login_data_password.bind(this)
this.Login_data_username=this.Login_data_username.bind(this)
this.MainRedirect=this.MainRedirect.bind(this)
this.api_call_login=this.api_call_login.bind(this)
}
Login_data_username(e)
{
this.setState({username:e.target.value})
}
Login_data_password(password)
{
this.setState({password:password.target.value})
}
MainRedirect()
{
window.location = '/main';
}
api_call_login()
{
Supers.post('http://127.0.0.1:8000/user_ops/user_login/')
.send({'username':this.state.username,'password':this.state.password})
.then(response => response.json())
.then(responseData=>{
console.log(responseData);
})
}
render()
{
return(
<div style={{background:'yellow'}}>
<div>
<h1 style={{marginLeft:550}}>Login Page</h1>
<div>
<p style={para_login_style}><b>Username</b></p>
<input type="text" style={Login_text_field_style} onChange={this.Login_data_username}/>
<h2>{this.state.username}</h2>
</div>
<div>
<p style={para_login_style} ><b>Password</b></p>
<input type="password" style={password_style} onChange={this.Login_data_password}/>
</div>
<div>
<button style = {Login_Submit_style} onClick={this.api_call_login}> Log in </button>
</div>
</div>
</div>
)
}
}
This is the Format in which i get the response:
{"Successful_Login": "True", "token": "d278f30445aa0c37f274389551b4faafee50c1f2"}
So ideally i would like to store the values for both the keys returned from the json output.Adn when i use response.body,i am able to get the data in the above format.

I don't know if this will be helpful to you, but I'll try.
Things like XHR calls from a browser to an API are done asynchronously. What you get back is a promise that will execute a function you give it when the call to the API is completed. Your code rightly has a callback function.
However, I don't think that callback function can call setState, because I think (I might be wrong) React wouldn't like it.
I use Redux for React as a way of storing stuff that the rest of the app can just grab when it needs it. Better still, Redux is integrated into React in such a way that whenever this central database is updated, any component that pulls in a piece of data from it (via props) gets updated (re-rendered) automatically.
I think I should point you to the documentation for Redux for more information. There are alternatives to Redux, too.
Good luck, and ask more questions if you get stuck.

In order to set a new state with the values from a json response, I ideally call this.setState right in your promise response.
api_call_login()
{
Supers.post('http://127.0.0.1:8000/user_ops/user_login/')
.send({'username':this.state.username,'password':this.state.password})
.then(response => response.json())
.then(responseData=>{
this.setState({
Successful_Login: responseData.Successful_Login,
token: responseData.token
})
}
state will be updated when response arrives.
If possible try to use lowercase or camelCase to your keys.

It would be great if you could post link where we can see what exactly is going on, but the way I understand this you would have to add .set('Accept', 'application/json') in your request to get correct json. So, your code should be like:
Supers.post('http://127.0.0.1:8000/user_ops/user_login/')
.send({'username':this.state.username,'password':this.state.password})
.set('Accept', 'application/json')
.then(response => response.json())
.then(responseData=>{
console.log(responseData);
})
Since I cannot test, you would have to look if it works. Alternatively, I would suggest you to try using superagent
Let me know if it helps!

Related

How to use fetch() in react front-end to get data from express back-end?

I'm trying to make a full-stack web-app using react and express. It's going pretty well atm but here's my problem:
So I have express running in back-end. All paths are used by react router except for '/api'. At the '/api/blogposts' path my server.js send the results of a query I made to the mySQL server. (I've checked it and this part works. If I browse to /api/blogposts my browser shows a json with the contents of my blogposts table).
My problem is with getting it to show in my react front-end. I'm trying to use fetch() but it doesn't work. Here's my code for the component that is supposed to fetch the blogposts:
import React from 'react';
import './Blogposts.css';
import SingleBpost from '../SingleBpost/SingleBpost.js';
class Blogposts extends React.Component {
constructor(props) {
super(props);
this.state = {
receivedPosts: []
};
}
async getBpostsFromServer() {
const response = await fetch("/api/blogposts");
let myPosts = await response.json();
this.setState({receivedPosts: myPosts});
}
componentDidMount() {
this.getBpostsFromServer();
}
render() {
console.log(this.state.receivedPosts);
return(
<div id="Blogposts">
<SingleBpost title="OwO" date="18/12/2021" author="Kepos Team" body="Hello, this is a test for the blogposts!" />
</div>
);
}
}
export default Blogposts;
Just to clarify the {this.state.generateBlogpost()} in the render method is just to check if I can get the data for now. Once this works I will feed it into another component's props like this:
<SingleBpost title={this.state.generateBlogpost().title} date={this.state.generateBlogpost().date} author={this.state.generateBlogpost().author} body={this.state.generateBlogpost().body} />
Anyways: does anyone know why this doesn't work? I've tried a few things but I just can't get it to work. What am I doing wrong?
Thanks in advance for any help!
You need to set the state of the variable receivedPosts in the fetch function like this :
this.setState({receivedPosts: results});
Also, you can call the function generateBlogpost() at the load of the Component Blogposts by adding the following function :
componentDidMount() {
this.generateBlogpost();
}
this one is useless
.then((results) => {
this.state.receivedPosts = results;
});
return this.state.receivedPosts;
}
//instead you should use setState({receivedPosts: data.data})

Codesandbox.io sending back html data instead of Json data

I'm currently working on a code problem on codesandbox where I am trying to use a http get request to retrieve json data from the link provided. However, when I console.log the response, I'm only receiving html data, which I have never seen before when making an http request. Has anyone else run into this issue with displaying JSON data and have tips for using codesandbox?
Thank you!
import React, { useState } from "react";
import "../styles.css";
import axios from "axios";
export default function App() {
axios
.get(`www.sbir.gov/api/solicitations.json?keyword=sbir`)
.then((response) => {
console.log(response);
})
.catch((error) => {
console.log(error);
});
return (
<div className="App">
<h1>Hello CodeSandbox</h1>
<h2>Start editing to see some magic happen!</h2>
</div>
);
}
Instead of console.log(response)
Try
console.log(response.json())
I'm not sure why this is the case, but you need to use https.
In your case you should be using https://www.sbir.gov/api/solicitations.json?keyword=sbir instead of www.sbir.gov/api/solicitations.json?keyword=sbir.
I found an example codesandbox here, when you remove https://, console logging the response outputs a html script.

Accessing JSON object within Object using React/Axios

I’m working with an API that shows data for cryptocurrencies called CryptoCompare. I’m a React noob but I’ve managed to use Axios to do the AJAX request. However I’m having trouble accessing the JSON elements I want.
Here’s what the JSON looks like: https://min-api.cryptocompare.com/data/all/coinlist
Here is my request:
import React, { Component } from 'react';
import './App.css';
import axios from "axios";
var NumberFormat = require('react-number-format');
class App extends Component {
constructor(props) {
super(props);
this.state = {
coinList: []
};
}
componentDidMount() {
axios.get(`https://min-api.cryptocompare.com/data/all/coinlist`)
.then(res => {
const coins = res.data;
//console.log(coins);
this.setState({ coinList: coins});
});
}
// Object.keys is used to map through the data. Can't map through the data without this because the data is not an array. Map can only be used on arrays.
render() {
console.log(this.state.coinList.Data);
return (
<div className="App">
{Object.keys(this.state.coinList).map((key) => (
<div className="container">
<span className="left">{key}</span>
<span className="right"><NumberFormat value={this.state.coinList[key].CoinName} displayType={'text'} decimalPrecision={2} thousandSeparator={true} prefix={'$'} /></span>
</div>
))}
</div>
);
}
}
export default App;
I am able to output some JSON using console.log(this.state.coinList.Data);. It outputs the JSON object, but I am unable to console.log properties of the object itself.
How would I, for example, output the CoinName property of the first element 42?
console.log(this.state.coinList.Data.CoinName) doesn’t work
nor does console.log(this.state.coinList.Data[0].CoinName) etc…
You are iterating over this.state.coinList while you want to iterate over this.state.coinList.Data.
Try this:
render() {
const data = this.state.coinList.Data;
if (data == null) return null;
return (
<div className="App">
{Object.keys(data).map((key) => (
<div className="container">
<span className="left">{key}</span>
<span className="right"><NumberFormat value={data[key].CoinName} displayType={'text'} decimalPrecision={2} thousandSeparator={true} prefix={'$'} /></span>
</div>
))}
</div>
);
}
CodeSandbox here: https://codesandbox.io/s/3rvy94myl1
I also stumbled with that same problem as yours. You cannot access an object inside a data because it is empty when the render happens. What I did was I made a conditional render where if the data is empty, it will just show a loading screen or something like that. And when the data loads , it will access the object inside that data. I can now access the object inside because I waited for the data to load inside render.
I hope this answer can help future react users
return (
<div>
{this.state.coinList.length>0? <h1>{this.state.coinList[0].coinName}</h1>: "Loading"}
</div>
);
}
Added: To console.log the data , you can create a new component inside the conditional render. Inside that component, you can access all the data you want because it is rendered after the data is loaded.
You're might have to parse the JSON. Might be good to do that before you save it.
const coins = JSON.parse(res.data)

Accessing state in React render method after API request

I'm working on my first complicated React app and I am making a request to a movie API. My site allows the user to do a search in a searchbar for whatever movie, show, actor, etc... that they are searching for. I'm pulling the user's search query and inserting it into an api request like this:
export const getDetails = (id) => {
return new Promise(function(resolve, reject) {
axios.get(`https://api.themoviedb.org/3/movie/` + id +`?api_key=&language=en-US`)
.then(function(response) {
resolve(response)
})
.catch(function(error) {
reject(error)
})
})
}
I'm able to get the data like this and console.log it:
import React, { Component } from 'react';
import Header from '../header';
import {Link} from 'react-router-dom';
import axios from 'axios';
import Footer from '../Footer.js';
import Searchbar from '../header/searchbar.js';
import List from '../results/list';
import {getDetails} from '../api/getDetails';
class Detail extends Component {
constructor(props) {
super(props);
this.state = {
id: this.props.match.params.id,
result: null,
error: false,
}
}
componentWillMount() {
getDetails(this.state.id).then(function(response){
this.setState({result: response});
console.log(response.data.original_title);
console.log(response.data.homepage);
console.log(response.data.popularity);
console.log(response.data.release_data);
console.log(response.data.overview);
}.bind(this)).catch(function(err) {
this.setState({
result:"There was a problem loading the results. Please try again.",
error: true
})
}.bind(this))
}
render() {
return(
<div>
<Header/>
<div className="details-container">
<h2>Details: </h2>
</div>
</div>
)
}
}
export default Detail
Console.logging it in the componentWillMount function successfully logs the data but I am not able to access the data in the render function via something like {response.data.orginal_title). How would I render the data being logged in componentWillMount?
TLDR; You can access your state variables from within your render function via this.state. Something like: console.log(this.state.result.data.origin_title) outside of the jsx and {this.state.response.data.orginal_title} inside the jsx.
P.S. You are using the correct this.
The following are picky recommendations and explanations, feel free to disregard.
It's recommended to make requests for data in componentDidMount. That can be read here in the docs for componentDidMount.
You're using arrow functions already in your get details function, if you convert the rest of your functions to arrow functions you no longer have to explicitly bind this to each one; it's automatically set be the this of it's parent. See the "No Separate This" section in the MDN docs
If you don't need any of the header information I would save response.data into your state so you don't have to type as much when you want to access the data. this.state.result.original_title vs this.state.result.data.original_title. That's just me and I'm lazy.
axios does return a promise like Eric said so you don't actually need to wrap it in the extra promise. You can just straight up return it and since arrow functions automatically return one line expressions you can spiff that up into a one liner:
export const getDetails = id => axios.get(`https://api.themoviedb.org/3/movie/${id}?api_key=&language=en-US`)
Finally you should be able to access the data you've stored in your state from your render function as mentioned in #3 above. Outside of the JSX you can console.log it like normal console.log(this.state.result), inside your JSX, however, you will need to make sure you escape with {} like: <div>{this.result.original_title}</div>
Small working example here: https://codesandbox.io/s/zqz6vpmrw3
You can simply use
{this.state.result}
inside the render.

Angular 2 - Using/displaying JSON data fetched through HTTP, or mocked

I'm working on an Angular 2 application, and I'm trying to use JSON data, either local/mocked or fetched via HTTP, and display it on a component. I have an injectable service that will do the fetching/mocking -
import { Injectable } from 'angular2/core';
#Injectable()
export class TestService {
testString:string = "";
testDetails: string = "";
constructor() { }
getTestDetails(): Promise<string> {
this.testDetails = {
"status": "success",
"message": "Data save successful",
"data": {
"Random_Data_1": "Random Data 1",
"Random_Data_2": "Random Data 2"
}
};
return Promise.resolve(JSON.stringify(this.propertyDetails));
}
}
And then I have a component that uses the service via Dependency Injection -
import { Component, OnInit } from 'angular2/core';
import {TestService} from "./test.service";
#Component({
selector: 'test',
templateUrl: './test.component.html',
styleUrls: []
})
export class TestComponent implements OnInit {
testDetails: string = "";
constructor(private testService: TestService) { }
ngOnInit() {
this.display();
}
display(): void {
this.testService.getTestDetails()
.then(
testDetails => {
this.testDetails = JSON.parse(testDetails);
},
errorMessage => {
console.error("Something failed trying to get test details");
console.error(errorMessage);
}
);
}
}
The component HTML -
<div class="content">
<p> Test Details </p>
<p> {{ testDetails.data.Random_Data_1 }} </p>
</div>
The problem is, the HTML is erroring out trying to display the items in the testDetails JSON. I initially used it with md-tabs, so the first try would error out, but the other tabs would read the data fine. Also, the ngOnInit would be called twice when the error occurs. I have narrowed it down to the data coming in and the object types that is causing me the headache.
I know I can create a Details class and declare testDetails of type Details, and then map the JSON data into the class, but the thing is, I want to work with generic data, and only know a few components that will be present in the data. Is there a way to read the JSON, and use the data without having to define a separate class for each scenario ?
I have a plunker with the most basic stuff set up. The actual setup runs fine on my local system up until where I try to access the JSON data in the HTML, at which point the browser throws a cryptic error. The skeleton code doesn't even run on Plunker. That said, the structure in the Plunker defines the structure of my app and the data flow. Plunker with the basic setup
What is the best way to achieve this ? What is the standard/best practice to do this ?
Throwing another option out there, since you asked about best way to achieve this. Might not be the best idea, this is subjective ;) But if I were you...
Thinking about the future, where you will use real backend, it could be nice to use mock json file. If/when you move over to a real backend, you wouldn't basically need to change anything else but the url of the requests :)
So I set up a simple example for you. Here I used Observables, but you can use Promises if you prefer that. Here's more info on HTTP if you want/need to read up on that. Most important thing is that you have the HttpModule imported in your app module.
You have your file with JSON and in your service make http-requests to that:
getTestDetails() {
return this.http.get('src/data.json')
.map(res => res.json())
}
Your display-method:
display() {
this.testService.getTestDetails()
.subscribe(data => {
this.testDetails = data;
});
}
And in the template use the safe navigation operator to safeguard null/undefined values:
<div class="content">
<p> Test Details </p>
<p> {{ testDetails?.data?.Random_Data_1 }} </p>
</div>
Here's a
Demo
As said, this is to give another approach on how to implement the things you want to achieve, and this would probably be my preferred way :)
Use
<p *ngIF="testDetails.data.Random_Data_1 "> {{ testDetails.data.Random_Data_1 }} </p>
This is because there is no data initially.Hope this helps you.