Accessing state in React render method after API request - json

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.

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})

how can I set a global function for call Apis in NUXT?

after some google searched,
I am doing this in plugins/callApi.js
import axios from 'axios';
import Vue from 'vue';
Vue.use(callApi);
export default async (apiUrl, postData, headers = {}) => {
let msg = await axios.post(https://my-api-location.com' + apiUrl,postData);
return msg.data;
};
then set in nuxt.config.js
plugins: [
'~plugins/callApi.js']
when I want to use it
const msgData = await callApi('/api/news/getNewsList', postData);
if (msgData.response === 'success') { .......
but when I start yarn dev, it hightlight "Vue.use(callApi);" part and says "callApi is not defined"
how cant I fix it? thanks a lot :)
I actually re-read your answer because I was a little confused.
So, in your callApi.js, you define what you want there, but you are calling Vue.use(callApi) in the file where you are actually defining what callApi will be.
At the moment the compiler goes to Vue.use(callApi), this variable "callApi" is not defined yet (because it will only be available after it finishes compiling this very file).
So just do the
import axios from 'axios';
import Vue from 'vue';
export default async (apiUrl, postData, headers = {}) => {
let msg = await axios.post(https://my-api-location.com' + apiUrl,postData);
return msg.data;
};
then, by setting the plugin path on the plugins property in the nuxt.config file (exactly the way you did), the very callApi file will be automatically called (try to put a console log in your callApi file, and you'll see it logging when you start your application).
An example of what you want:
https://codesandbox.io/s/nuxt-app-demovue-ssr-forked-s94rz?file=/pages/index.vue
Now in your plugin, you have to decide exactly what you want to do. you might want to expose the function or make it globally available, that's up to you!
For this last option, you might want to take a look here:
Vue/Nuxt: How to define a global method accessible to all components?
Good luck!

Fetch data from JSON local file in React

I would need some help to fetch some data in a local file calling data.json to my React component. The data is very simple, but when i tried to connect with my component, all I have in the component appear less than the information I added from the data file.
this is my data.json:
{ "data": [
{ "id": "1",
"name": "john"
},
]}
...and this is my component where i need to fetch the data and where everything is working less than the information I want to connect and appear completely blank.
This is the function where i past the information in the first instant to send the information to the state.
function RenderFoo({data, name}) {
return (
<div>{data.name}</div>
)}
export default class Example extends Component {
constructor(props) {
super(props);
this.state = {
data : [data]
}}
render() {
const dataExample = this.state.data.map((element) => {
return (
<div key={element.url}>
<RenderFoo data ={ element }/>
</div>
)})
return (
<div>
<Card >
{dataExample}
</Card>
</div>)
The screen appear blank in the part of the component that I connect the data but without any error in the other part of the component where everything is working. I think the sintaxis to get the information is not right any reason don't read the data.
And if I change data.name in the function is giving error. I don't know if I'm missing the key or so.
Moving all the data to the main component is worthy neither because I will need to increase the data after and I will thousands of lines, and create a complete back end would be pointless for this kind of application
Thanks
Your state has a property data which is an array. Each element of that array is an object with properties id and name -- and maybe url?
So then what are the props supposed to be here:
function RenderFoo({data, name}) {
return (
<div>{data.name}</div>
)}
Does RenderFoo take a single property data which is the the whole data object? Or does it take the properties of data as individual props? Either is fine, but it feels like you are mixing the two. So remove name from the props.
<div key={element.url}>
Do all elements in your data have a url property? I'm only asking because your sample just shows name and id.
this.state = {
data : [data]
}}
This also looks suspect to me. You are taking the variable data and making it a single element in an array. I'm not sure exactly what your data variable looks like, but I think you probably want to set it as the entire state, this.state = data.
Try this:
import React, { Component } from "react";
import json from "./data";
function RenderFoo({ data }) {
return <div>{data.name}</div>;
}
export default class Example extends Component {
constructor(props) {
super(props);
this.state = {
data: json.data
};
}
render() {
return (
<div>
{this.state.data.map((element) => (
<div key={element.id}>
<RenderFoo data={element} />
</div>
))}
</div>
);
}
}
I removed the <Card> component because I don't know where you imported it from, but you can easily add it back it.

React Unable to Access Json Resposne from API

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!

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.