ReactJS – if value is undefined, display placeholder image - reactjs

0
I am creating a find nearest restaurant app using Google Places API. I am calling for a background image in my ResultItem component in a prop <ResultsItem name={places.name} image={Thumbnail} rating={places.rating} rating_total={places.user_ratings_total} />
This image is defined as Thumbnail in const above this part of the code. My code runs smoothly but as soon as places.photos[0] returns as undefined (meaning that it is Google Place that doesn't have any image uploaded) i get an error saying:
Unhandled Rejection (TypeError): Cannot read property '0' of undefined
I think what I have to do is check whether places.photos[0] is undefined or not but I do not seem to get it right...
My goal is to display another placeholder image when this value turns out undefined. If it is defined though the component should take the image from google places api.
This is what I have tried to do with the const Thumbnail to achieve it, but didnt work:
const Thumbnail =
places && places.photos[0]
? `https://maps.googleapis.com/maps/api/place/photo?maxwidth=400&photoreference=${places.photos[0].photo_reference}&key=MYAPIKEY`
: 'https://www.xy.com/images/placeholder.jpg';
Can someone help me?
FULL COMPONENT:
import React, { Component } from 'react';
// Imports
import axios from 'axios';
import Script from 'react-load-script';
import Placeholder from './Placeholder.jsx';
import FadeIn from 'react-fade-in';
import {
Spinner,
Paragraph,
SideSheet,
Tooltip,
IconButton,
SearchInput
} from 'evergreen-ui';
import ResultsItem from '../../components/ResultsItem/ResultsItem.jsx';
import Geocode from 'react-geocode';
// Styles
import './Search.scss';
class Autocomplete extends Component {
// Define Constructor
constructor(props) {
super(props);
// Declare State
this.state = {
type: 'restaurant',
radius: 10,
lat: '59.0738',
lng: '41.3226',
city: '',
query: '',
open: false,
places: [],
place_detail: [],
sidebar: false,
loading: true
};
this.currentLocationOnClick = this.currentLocationOnClick.bind(this);
this.handlePlaceSelect = this.handlePlaceSelect.bind(this);
}
currentLocationOnClick = async () => {
let { lat, lng, places } = this.state;
const URL = `https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=${lat},${lng}&type=restaurant&radius=${5 *
1000}&key=MY_API_KEY`;
navigator.geolocation.getCurrentPosition(
async position => {
this.setState({ lat: position.coords.latitude });
this.setState({ lng: position.coords.longitude });
const URL = `https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=${
position.coords.latitude
},${position.coords.longitude}&type=restaurant&radius=${5 *
1000}&key=MY_API_KEY`;
const response = await axios.get(URL);
console.log(response.data);
places = response.data.results;
this.setState({ places });
},
error => {
console.log('Error getting location');
}
);
};
async componentDidMount() {
const url = `https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=
${this.state.lat},${this.state.lng}type=restaurant&radius=${2 *
1000}&key=MY_API_KEYE`;
const response = await fetch(url);
const data = await response.json();
this.setState({ places: data.results });
console.log(data.results);
}
handleScriptLoad = () => {
// Declare Options For Autocomplete
const options = {
types: ['address']
}; // To disable any eslint 'google not defined' errors
// Initialize Google Autocomplete
/*global google*/ this.autocomplete = new google.maps.places.Autocomplete(
document.getElementById('autocomplete'),
options
);
// Avoid paying for data that you don't need by restricting the set of
// place fields that are returned to just the address components and formatted
// address.
this.autocomplete.setFields(['address_components', 'formatted_address']);
// Fire Event when a suggested name is selected
this.autocomplete.addListener('place_changed', this.handlePlaceSelect);
};
handlePlaceSelect = async () => {
let { query, lat, lng } = this.state;
this.setState({ loading: true });
// Extract City From Address Object
const addressObject = this.autocomplete.getPlace();
const address = addressObject.address_components;
Geocode.setApiKey('MY_API_KEY');
// Check if address is valid
let city;
if (address) {
city = address[0].long_name;
query = addressObject.formatted_address;
}
try {
const response = await Geocode.fromAddress(query);
({ lat, lng } = response.results[0].geometry.location);
} catch (error) {
console.error(error);
}
let places;
try {
const URL = `https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=${lat},${lng}&type=restaurant&radius=${5 *
1000}&key=MY_API_KEY`;
const response = await axios.get(URL);
console.log(response.data);
places = response.data.results;
} catch (error) {
console.log(error.message);
}
this.setState({ query, places, city, lat, lng });
setTimeout(() => this.setState({ loading: false }), 400);
};
render() {
const { loading } = this.state;
return (
<div>
<div className="flex align-center">
<div className="search">
<SearchInput
id="autocomplete"
placeholder="Search by address"
width="100%"
height={56}
/>
<Script
url="https://maps.googleapis.com/maps/api/js?key=MY_API_KEY&libraries=places,geometry&callback=initAutocomplete"
onLoad={this.handleScriptLoad}
/>
</div>
<div className="current-location">
<Tooltip content="Use current location">
<IconButton
icon="locate"
iconSize={16}
height={32}
onClick={this.currentLocationOnClick}
>
{this.state.lat} & {this.state.lng}
</IconButton>
</Tooltip>
</div>
</div>
<div className="results">
{this.state.places.map(places => {
const Thumbnail = `https://maps.googleapis.com/maps/api/place/photo?maxwidth=400&photoreference=${places.photos[0].photo_reference}&key=MY_API_KEY
`;
return (
<div
className="results-flex"
onClick={async () => {
let loading;
let sidebar;
let place_detail;
try {
const URL = `https://maps.googleapis.com/maps/api/place/details/json?place_id=${places.place_id}&fields=name,rating,formatted_phone_number&key=
MY_API_KEY`;
const response = await axios.get(URL);
console.log(response.data);
place_detail = response.data.result;
} catch (error) {
console.log(error.message);
}
this.setState(
{ place_detail, sidebar: true }
// () => this.props.sideBarOpen()
);
}}
>
{this.state.loading ? (
<>
<div className="flex justify-center">
<Placeholder />
</div>
</>
) : (
<FadeIn>
<ResultsItem
name={places.name}
image={Thumbnail}
rating={places.rating}
rating_total={places.user_ratings_total}
/>
</FadeIn>
)}
</div>
);
})}
<SideSheet
isShown={this.state.sidebar}
onCloseComplete={() => this.setState({ sidebar: false })}
>
<Paragraph margin={40}>{this.state.place_detail.name}</Paragraph>
</SideSheet>
</div>
</div>
);
}
}
export default Autocomplete;

The problem might be arising beacuse when a Google Place doesn't have any image uploaded then there is not any element pointing to "places.photos[0]" which results in error: Cannot read property '0' of undefined.
So in const Thumbnail u must also check whether places.photos array exist or not.
I hope the below code solves your issue.
const Thumbnail =
places && places.photos && places.photos[0]
? `https://maps.googleapis.com/maps/api/place/photo?maxwidth=400&photoreference=${places.photos[0].photo_reference}&key=MYAPIKEY`
: 'https://www.xy.com/images/placeholder.jpg';

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draft.js - retrieve formatted text from db

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In Post.js, I want to retrieve and display the formatted text from the db.
I've read that in order to do this, I must use convertToRaw() and then convertFromRaw() when retrieving it from the db but I'm having the same problems as this (I'm receiving the cors error and Unexpected token u in JSON at position 0) whenever I use convertFromRaw() and try to retrieve the formatted text from the db.
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ReactJS – how to check whether value is undefined

I am creating a find nearest restaurant app using Google Places API. I am calling for a background image in my ResultItem component in a prop <ResultsItem name={places.name} image={Thumbnail} rating={places.rating} rating_total={places.user_ratings_total} />
This image is defined as Thumbnail in const above this part of the code. My code runs smoothly but as soon as places.photos[0] returns as undefined (meaning that it is Google Place that doesn't have any image uploaded) i get an error saying:
Unhandled Rejection (TypeError): Cannot read property '0' of undefined
I think what I have to do is check whether places.photos[0] is undefined or not but I do not seem to get it right...
My goal is to display another placeholder image when this value turns out undefined. If it is defined though the component should take the image from google places api.
Can someone help me?
FULL COMPONENT:
import React, { Component } from 'react';
// Imports
import axios from 'axios';
import Script from 'react-load-script';
import Placeholder from './Placeholder.jsx';
import FadeIn from 'react-fade-in';
import {
Spinner,
Paragraph,
SideSheet,
Tooltip,
IconButton,
SearchInput
} from 'evergreen-ui';
import ResultsItem from '../../components/ResultsItem/ResultsItem.jsx';
import Geocode from 'react-geocode';
// Styles
import './Search.scss';
class Autocomplete extends Component {
// Define Constructor
constructor(props) {
super(props);
// Declare State
this.state = {
type: 'restaurant',
radius: 10,
lat: '59.0738',
lng: '41.3226',
city: '',
query: '',
open: false,
places: [],
place_detail: [],
sidebar: false,
loading: true
};
this.currentLocationOnClick = this.currentLocationOnClick.bind(this);
this.handlePlaceSelect = this.handlePlaceSelect.bind(this);
}
currentLocationOnClick = async () => {
let { lat, lng, places } = this.state;
const URL = `https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=${lat},${lng}&type=restaurant&radius=${5 *
1000}&key=MY_API_KEY`;
navigator.geolocation.getCurrentPosition(
async position => {
this.setState({ lat: position.coords.latitude });
this.setState({ lng: position.coords.longitude });
const URL = `https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=${
position.coords.latitude
},${position.coords.longitude}&type=restaurant&radius=${5 *
1000}&key=MY_API_KEY`;
const response = await axios.get(URL);
console.log(response.data);
places = response.data.results;
this.setState({ places });
},
error => {
console.log('Error getting location');
}
);
};
async componentDidMount() {
const url = `https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=
${this.state.lat},${this.state.lng}type=restaurant&radius=${2 *
1000}&key=MY_API_KEYE`;
const response = await fetch(url);
const data = await response.json();
this.setState({ places: data.results });
console.log(data.results);
}
handleScriptLoad = () => {
// Declare Options For Autocomplete
const options = {
types: ['address']
}; // To disable any eslint 'google not defined' errors
// Initialize Google Autocomplete
/*global google*/ this.autocomplete = new google.maps.places.Autocomplete(
document.getElementById('autocomplete'),
options
);
// Avoid paying for data that you don't need by restricting the set of
// place fields that are returned to just the address components and formatted
// address.
this.autocomplete.setFields(['address_components', 'formatted_address']);
// Fire Event when a suggested name is selected
this.autocomplete.addListener('place_changed', this.handlePlaceSelect);
};
handlePlaceSelect = async () => {
let { query, lat, lng } = this.state;
this.setState({ loading: true });
// Extract City From Address Object
const addressObject = this.autocomplete.getPlace();
const address = addressObject.address_components;
Geocode.setApiKey('MY_API_KEY');
// Check if address is valid
let city;
if (address) {
city = address[0].long_name;
query = addressObject.formatted_address;
}
try {
const response = await Geocode.fromAddress(query);
({ lat, lng } = response.results[0].geometry.location);
} catch (error) {
console.error(error);
}
let places;
try {
const URL = `https://maps.googleapis.com/maps/api/place/nearbysearch/json?location=${lat},${lng}&type=restaurant&radius=${5 *
1000}&key=MY_API_KEY`;
const response = await axios.get(URL);
console.log(response.data);
places = response.data.results;
} catch (error) {
console.log(error.message);
}
this.setState({ query, places, city, lat, lng });
setTimeout(() => this.setState({ loading: false }), 400);
};
render() {
const { loading } = this.state;
return (
<div>
<div className="flex align-center">
<div className="search">
<SearchInput
id="autocomplete"
placeholder="Search by address"
width="100%"
height={56}
/>
<Script
url="https://maps.googleapis.com/maps/api/js?key=MY_API_KEY&libraries=places,geometry&callback=initAutocomplete"
onLoad={this.handleScriptLoad}
/>
</div>
<div className="current-location">
<Tooltip content="Use current location">
<IconButton
icon="locate"
iconSize={16}
height={32}
onClick={this.currentLocationOnClick}
>
{this.state.lat} & {this.state.lng}
</IconButton>
</Tooltip>
</div>
</div>
<div className="results">
{this.state.places.map(places => {
const Thumbnail = `https://maps.googleapis.com/maps/api/place/photo?maxwidth=400&photoreference=${places.photos[0].photo_reference}&key=MY_API_KEY
`;
return (
<div
className="results-flex"
onClick={async () => {
let loading;
let sidebar;
let place_detail;
try {
const URL = `https://maps.googleapis.com/maps/api/place/details/json?place_id=${places.place_id}&fields=name,rating,formatted_phone_number&key=
MY_API_KEY`;
const response = await axios.get(URL);
console.log(response.data);
place_detail = response.data.result;
} catch (error) {
console.log(error.message);
}
this.setState(
{ place_detail, sidebar: true }
// () => this.props.sideBarOpen()
);
}}
>
{this.state.loading ? (
<>
<div className="flex justify-center">
<Placeholder />
</div>
</>
) : (
<FadeIn>
<ResultsItem
name={places.name}
image={Thumbnail}
rating={places.rating}
rating_total={places.user_ratings_total}
/>
</FadeIn>
)}
</div>
);
})}
<SideSheet
isShown={this.state.sidebar}
onCloseComplete={() => this.setState({ sidebar: false })}
>
<Paragraph margin={40}>{this.state.place_detail.name}</Paragraph>
</SideSheet>
</div>
</div>
);
}
}
export default Autocomplete;
I think the best solution is to assign it to a variable :
const photoReference = places && places.photos[0] ? places.photos[0].photo_reference : placeholder;
try using if else for it
for eg:
if(!!places.photos[0]) {
const Thumbnail =
`https://maps.googleapis.com/maps/api/place/photo?maxwidth=400&photoreference=${places.photos[0].photo_reference}&key=MY_API_KEY
}
else { const Thumbnail = `another image url` }

How to add page number to the URL

Could someone please tell me how can I add page number to my url. The component is as follows:
/** NPM Packages */
import React, { Component } from "react";
import { connect } from "react-redux";
import { Spinner, Pagination } from "react-bootstrap";
//import styles from "./App.module.css";
/** Custom Packages */
import List from "../List";
//import fetchCategories from "../../../actions/configuration/category/fetchCategories";
import deleteCategory from "../../../actions/configuration/category/deleteCategory";
import API from "../../../../app/pages/utils/api";
class Category extends Component {
constructor(props) {
super(props);
this.state = {
mesg: "",
mesgType: "",
isLoading: true,
total: null,
per_page: null,
current_page: 1,
pdata: []
};
this.fetchCategoriesAPI = this.fetchCategoriesAPI.bind(this);
}
fetchCategoriesAPI = async pno => {
await API.get("categories?offset=" + (pno.index+1))
.then(res => this.setState({ pdata: res.data }))
.then(() => this.props.passToRedux(this.state.pdata))
.catch(err => console.log(err));
};
componentDidMount = async () => {
const { state } = this.props.location;
if (state && state.mesg) {
this.setState({
mesg: this.props.location.state.mesg,
mesgType: this.props.location.state.mesgType
});
const stateCopy = { ...state };
delete stateCopy.mesg;
this.props.history.replace({ state: stateCopy });
}
this.closeMesg();
await this.fetchCategoriesAPI(1);
this.setState({ isLoading: false });
};
onDelete = async id => {
this.props.removeCategory(id);
await deleteCategory(id).then(data =>
this.setState({ mesg: data.msg, mesgType: "success" })
);
this.closeMesg();
};
closeMesg = () =>
setTimeout(
function() {
this.setState({ mesg: "", mesgType: "" });
}.bind(this),
10000
);
/** Rendering the Template */
render() {
let activePage = this.state.pdata.currPage;
let items = [];
let totalPages = Math.ceil(this.state.pdata.totalCount / 10);
for (let number = 1; number <= totalPages; number++) {
items.push(
<Pagination.Item key={number} active={number == activePage}>
{number}
</Pagination.Item>
);
}
const paginationBasic = (
<div>
<Pagination>
{items.map((item,index)=>{
return <p key={index} onClick={() => this.fetchCategoriesAPI({index})}>{item}</p>
})}
</Pagination>
<br />
</div>
);
const { mesg, mesgType, isLoading } = this.state;
return (
<>
{mesg ? (
<div
className={"alert alert-" + mesgType + " text-white mb-3"}
role="alert"
>
{mesg}
</div>
) : (
""
)}
{isLoading ? (
<div className="container-fluid">
<h4
className="panel-body"
style={{ "text-align": "center", margin: "auto" }}
>
Loading
<Spinner animation="border" role="status" />
</h4>
</div>
) : (
<div>
<List
listData={this.props.categories}
listName="category"
_handleDelete={this.onDelete.bind(this)}
/>
{paginationBasic}
</div>
)}
</>
);
}
}
const matchStatestoProps = state => {
return { categories: state.categories };
};
const dispatchStatestoProps = dispatch => {
return {
passToRedux: pload =>
dispatch({ type: "FETCH_CATEGORIES", payload: pload }),
removeCategory: id => dispatch({ type: "DELETE_CATEGORY", payload: id })
};
};
export default connect(matchStatestoProps, dispatchStatestoProps)(Category);
the route is as follows:
<Route exact path="/categories/:page?" component={Category} />
So basically I want the page number to be displayed in the URL. Also if I change the page number, the data should load the corresponding page. Please help me
Could someone please help me out?
In a class component:
Your router will pass match in as a prop. When your component mounts, get this.props.match.params.page and load the data accordingly:
class MyComponent extends React.Component {
componentDidMount () {
// get the 'page' param out of the router props.
// default to 0 if not specified.
const { page = 0 } = this.props.match.params;
// it comes in as a string, parse to int
const p = parseInt(page, 10);
// do whatever you need to do (load data, etc.)
}
}
In a function component:
In a function component, you can get the page param via react-router's useParams hook:
import { useParams } from 'react-router-dom';
function MyComponent () {
const { page } = useParams(); // get the 'page' router param
const p = parseInt(page, 10); // comes in as a string, convert to int
// do whatever you need to do with it
}
If you need prev/next navigation you can deduce those page numbers from the current page.
I made this quick example that demonstrates how to access and use the route's url parameters via react router's useParams hook and how to do it via the match prop with a class component.
You can get page number from props like this:
const matchStatestoProps = (state, ownProps) => {
return { id: ownProps.match.params.id; categories: state.categories };
};
In your routes:
<Route path="/page/:id" component={Page} />

React render array of images in array

end app for woocommerce store, but i have problem rendering the first image of array in
when i console.log(images.src) i see the list of urls of the images, but in img src= it return : TypeError: Cannot read property 'src' of undefined
I will be very thankful to help me correctly map the images.
here is my code:
class App extends React.Component {
constructor(props) {
super(props);
this.getPosts = this.getPosts.bind(this);
this.state = {
posts : [],
images: []
};
}
getPosts = async () => {
let res = await api.get("products", {
per_page: 20,
})
let { data } = await res;
this.setState({ posts: data });
}
componentDidMount = async () => {
await this.getPosts();
};
render() {
const { posts } = this.state;
const { images } = this.state
return(
<div>
<Head>
<title>Онлайн магазин KIKI.BG</title>
<link rel="icon" href="/favicon.ico" />
</Head>
<React.Fragment >
{posts.map((posts, index ) => {
{
posts.images.map((images, subindex) =>
console.log(images.src),
<img src={images[0].src} />
)}
return (
<div>
<h1>{posts.name}</h1>
<h2>{posts.price}</h2>
</div>
)})}
</React.Fragment>
</div>
)
}
}
export default App;
{posts.map((posts, index ) => {
{
posts.images.src.map((image, subindex) =>
<img src={image.src} />
)}
return (
<div>
<h1>{posts.name}</h1>
<h2>{posts.price}</h2>
</div>
)
})}
well, console.log(images.src) i see the list of urls of the images doesn't make any sense.. images is array. So images[0] should be image with data with property src on it?. Btw a lot of stuff in this code is just wrong.
Don't rebind getPosts already bound getPosts function in constructor (via class property) (getPosts). BTW you dont need to bind is here at all, its not called as a callback.
Its weird, that you call await res after api.get() ... shouldn't be it just await api.get()? Another await is usually used on fetch, when you do something like await response.json().
There is no need for async/await in componentDidMount
If getPosts will throw it will mess up your component, its better to handle error in catch and call props.onError(error) for example
You don't have any key attributes on element in map, thats wrong. You should put some unique id there (url fe? if not same, or id) for proper component re-render.
You have some weird brackets issue in your maps...
You shouldn't use more than one h1 one the page :-)
images.src should be string, not array...
Why is there subindex and index when u are not using it?
Why you store images when they are not filled anywhere? Are they in the response of get? Thats maybe why u get an TypeError !
I would add loading and no data message...
That would be my code:
import { Component, Fragment } from 'react';
class App extends Component {
static defaultProps = {
onError: console.error;
};
state = {
posts: [],
images: [],
loading: false,
};
// This could be done with hooks much better tho...
async componentDidMount () {
this.setState({ loading: true });
try {
await this._fetchData();
}
catch (error) {
this.props.onError(error); // Or something rendered in state.error?
}
finally {
this.setState({ loading: false });
}
}
render () {
const { images, posts, loading } = this.state;
if (!images.length) {
return <div>No data.</div>;
}
if (loading) {
return <div>Loading</div>;
}
const postBoxes = posts.map((post, index) => {
const image = images[index];
// Because you don't know, if that specific image is there... if this are your data..
const imageElement = image ?
<img src={image.src} alt="dont know" /> :
null;
const { name, price } = post;
// If name is unique, otherwise some id.
return (
<Fragment key={name} >
{imageElement}
<h2>{name}</h2>
<h3>{price}</h3>
</Fragment>
);
});
return (
<div>
<Head>
<title>Онлайн магазин KIKI.BG</title>
<link rel="icon" href="/favicon.ico" />
</Head>
<Fragment>
{postBoxes}
</Fragment>
</div>
);
}
async _fetchData () {
const { data } = await api.get('products', { per_page: 20 });
const { posts, images } = data;
this.setState({ posts, images });
}
}
export default App;
if console.log(images.src) -> gives list of images.
Then,
<img src={images.src[0]}/> -> should do the trick.
may be, Add a null check to be certain.
images.src[0] && <img src={images.src[0]}/>

Custom react hook triggers api call multiple times

I cannot figure out how to handle my function components calling my api repeatedly. I have two components which retrieve data, one of them calls the api twice. Once before the second component once after.
I am using a custom react hook and axios get method to retrieve the data. My two components are are nested. The first component when loads and fetches data. Inside this component is a child component which when renders it fetches data right before passing the first set of data as props to another child component. When it completes loading it reloads the first child component which again calls the api for data. I understand the function components reload on state change. I would be happy for it to not call the api a second time. Is there a way to check if it already has data and bypass the api call?
Custom hook to retrieve data
import React, { useState, useEffect, useReducer } from "react";
import axios from "axios";
const dataFetchReducer = (state, action) => {
switch (action.type) {
case "FETCH_INIT":
return { ...state, isLoading: true, hasErrored: false };
case "FETCH_SUCCESS":
return {
...state,
isLoading: false,
hasErrored: false,
errorMessage: "",
data: action.payload
};
case "FETCH_FAILURE":
return {
...state,
isLoading: false,
hasErrored: true,
errorMessage: "Data Retrieve Failure"
};
case "REPLACE_DATA":
// The record passed (state.data) must have the attribute "id"
const newData = state.data.map(rec => {
return rec.id === action.replacerecord.id ? action.replacerecord : rec;
});
return {
...state,
isLoading: false,
hasErrored: false,
errorMessage: "",
data: newData
};
default:
throw new Error();
}
};
const useAxiosFetch = (initialUrl, initialData) => {
const [url] = useState(initialUrl);
const [state, dispatch] = useReducer(dataFetchReducer, {
isLoading: false,
hasErrored: false,
errorMessage: "",
data: initialData
});
useEffect(() => {
let didCancel = false;
const fetchData = async () => {
dispatch({ type: "FETCH_INIT" });
try {
let result = await axios.get(url);
if (!didCancel) {
dispatch({ type: "FETCH_SUCCESS", payload: result.data });
}
} catch (err) {
if (!didCancel) {
dispatch({ type: "FETCH_FAILURE" });
}
}
};
fetchData();
return () => {
didCancel = true;
};
}, [url]);
const updateDataRecord = record => {
dispatch({
type: "REPLACE_DATA",
replacerecord: record
});
};
return { ...state, updateDataRecord };
};
export default useAxiosFetch;
Main component which renders the "CompaniesDropdown" twice inside
CompaniesDropdown is one of three dropdowns within the ListFilterContainer component but the only one which calls the api more than once. The other two dropdowns load by selection of the CompaniesDropdown.
import React, { useMemo, useEffect, useContext } from "react";
import InvoiceList from "../src/Components/Lists/InvoiceList";
import useAxiosFetch from "../src/useAxiosFetch";
import { ConfigContext } from "./_app";
import ListFilterContainer from "../src/Components/Filters/InvoiceFilters";
// import "../css/ListView.css";
const Invoices = props => {
const context = useContext(ConfigContext);
useEffect(() => {
document.title = "Captive Billing :: Invoices";
});
const {
data,
isLoading,
hasErrored,
errorMessage,
updateDataRecord
} = useAxiosFetch("https://localhost:44394/Invoice/GetInvoices/false", []);
const newInvoicesList = useMemo(
() => data
// .filter(
// ({ sat, sun }) => (speakingSaturday && sat) || (speakingSunday && sun)
// )
// .sort(function(a, b) {
// if (a.firstName < b.firstName) {
// return -1;
// }
// if (a.firstName > b.firstName) {
// return 1;
// }
// return 0;
// }),
// [speakingSaturday, speakingSunday, data]
);
const invoices = isLoading ? [] : newInvoicesList;
if (hasErrored)
return (
<div>
{errorMessage} "Make sure you have launched "npm run json-server"
</div>
);
if (isLoading) return <div>Loading...</div>;
const dataProps = {
data: invoices,
titlefield: "invoiceNumber",
titleHeader: "Invoice Number:",
childPathRoot: "invoiceDetail",
childIdField: "invoiceId",
childDataCollection: "invoiceData"
};
var divStyle = {
height: context.windowHeight - 100 + "px"
};
return (
<main>
<ListFilterContainer />
<section style={divStyle} id="invoices" className="card-container">
<InvoiceList data={dataProps} />
</section>
</main>
);
};
Invoices.getInitialProps = async ({ req }) => {
const isServer = !!req;
return { isServer };
};
export default Invoices;
Actual result is described above. My main concern is to not have the api calls more than once.
Here is some additional code to help. It is the filter control mentioned above. It, as you will notice really just contains dropdowns and a text box. The first dropdown is the one that calls the api twice. The second two are not visible until that one is selected.
import React, { useState, useMemo } from "react";
import CompaniesDropdown from "../Dropdowns/CompaniesDropdown";
import LocationsDropdown from "../Dropdowns/LocationsDropdown";
import AccountsDropdown from "../Dropdowns/AccountsDropdown";
import Search from "./SearchFilter/SearchFilter";
const InvoiceFilters = props => {
const [company, setCompany] = useState("");
const [location, setLocation] = useState(undefined);
const [account, setAccount] = useState(undefined);
const handleClientChange = clientValue => {
setCompany(clientValue);
};
const handleLocationsChange = locationValue => {
setLocation(locationValue);
};
const handleAccountsChange = AccountValue => {
setAccount(AccountValue);
};
return (
<section className="filter-container mb-3">
<div className="form-row">
<div className="col-auto">
<CompaniesDropdown change={e => handleClientChange(e)} />
</div>
<div className="col-auto">
<LocationsDropdown
selectedCompany={company}
change={e => handleLocationsChange(e)}
/>
</div>
<div className="col-auto">
<AccountsDropdown
selectedCompany={company}
change={e => handleAccountsChange(e)}
/>
</div>
<div className="col-auto">
<Search />
</div>
</div>
</section>
);
};
InvoiceFilters.getInitialProps = async ({ req }) => {
const isServer = !!req;
return { isServer };
};
export default InvoiceFilters;
Also the datalist
import React from "react";
import Link from "next/link";
import InvoiceListRecord from "./InvoiceListRecord";
const InvoiceList = props => {
let dataCollection = props.data.data;
return dataCollection.length == 0 ? "" : dataCollection.map((item, index) => {
return (
<section key={"item-" + index} className="card text-left mb-3">
<header className="card-header">
<span className="pr-1">{props.data.titleHeader}</span>
<Link
href={
"/" +
props.data.childPathRoot +
"?invoiceId=" +
item[props.data.childIdField]
}
as={
"/" +
props.data.childPathRoot +
"/" +
item[props.data.childIdField]
}
>
<a>{item[props.data.titlefield]}</a>
</Link>{" "}
</header>
<div className="card-body">
<div className="row">
<InvoiceListRecord
data={item}
childDataCollection={props.data.childDataCollection}
/>
</div>
</div>
</section>
);
});
};
InvoiceList.getInitialProps = async ({ req }) => {
console.log("Get Intitial Props works: Invoices Page!");
const isServer = !!req;
return { isServer };
};
export default InvoiceList;
and the list items component.
import React from "react";
const InvoiceListRecord = props => {
var invoiceData = JSON.parse(props.data[props.childDataCollection]);
return invoiceData.map((invKey, index) => {
return (
<div className="col-3 mb-1" key={"item-data-" + index}>
<strong>{invKey.MappedFieldName}</strong>
<br />
{invKey.Value}
</div>
);
});
};
export default InvoiceListRecord;
The API is not called more than once if the url is the same. It just gets the value from data variable. The api call is not made again, unless the url changes.
I created an example from your code, changing all the unknown components to div. I added a console.log in the useEffect of the useAxiosFetch hook. And to re-render the component, I added a button to increment the count.
You'll see that the console.log from the hook is printed only once, even though the component re-renders on every button click. The value just comes from the data variable from the hook and the api call is not made again and again.

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