I have the following spinner
import React, { Component } from 'react'
import './Spinner.scss'
export default class Spinner extends Component {
constructor(props) {
super(props);
this.state = {showLoading: true};
}
render () {
return (
<div className="spinner">
<div className="double-bounce1"></div>
<div className="double-bounce2"></div>
</div>
)
}
}
and from other component I would like to show or hide this spinner here is the code of the component:
import React, { Component } from 'react'
import RTable from '../../../components/RTable/RTable'
import Spinner from '../../../components/Spinner/Spinner'
import CsvDownload from '../containers/CsvDownloadContainer'
export default class Table extends Component {
_renderBreadcrumb () {
const { breadcrumb, handleBreadcrumbClick } = this.props
return (
<ol className="breadcrumb">
{(breadcrumb || []).map(el => {
return (
<li key={el.datasetKey}>
<a onClick={() => { handleBreadcrumbClick(el.granularity, el.datasetKey, el.datasetKeyHuman) }}>
{el.datasetKeyHuman}
</a>
</li>
)
})}
</ol>
)
}
render () {
const { datasetRows, columns, metadata, showLoading } = this.props
return (
<div className="row">
<div className="col-sm-12">
{this._renderBreadcrumb()}
<RTable rows={datasetRows} columns={columns} metadata={metadata} />
{ this.props.showLoading ? <Spinner /> : null }
<CsvDownload />
</div>
</div>
)
}
}
as you can see I trying to show or hide the spinner using:
{ this.props.showLoading ? <Spinner /> : null }
but I'm always getting undefinde. Some help please.
You have to move this
constructor(props) {
super(props);
this.state = {showLoading: true};
}
to your <Table /> component, otherwise you access showLoading from <Table />'s props, but it is not passed from anywhere.
Then change also
{ this.props.showLoading ? <Spinner /> : null }
to
{ this.state.showLoading ? <Spinner /> : null }
To show / hide <Spinner /> just call this.setState({ showLoading: Boolean }) in your <Table /> component.
Related
I had already found a solution by luck so I don't quite understand how it worked even after trying to read stuff online.
I am simply trying to get the array of comments inside the selectedDish prop. The selectedDish's state is populated inside the Main Component's function, and I am trying to access selectedDish's array of comments inside the DishDetail component.
I was able to get the comments by:
{ this.props.selectedDish && this.renderComments(this.props.selectedDish.comments)}
But I am unable to when I just do the following and receive this error "Cannot read property 'comments' of undefined":
{ this.renderComments(this.props.selectedDish.comments)}
Why does this work? Shouldn't this.props.selectedDish.comments be enough as I am able to successfully render the "renderDish(dish)" function?
Main Component
import React, { Component } from 'react';
import { Navbar, NavbarBrand } from 'reactstrap';
import Menu from './MenuComponent';
import Dishdetail from './DishdetailComponent';
import { DISHES } from '../shared/dishes';
class Main extends React.Component {
constructor() {
super();
this.state = {
dishes: DISHES,
selectedDish: null
};
// this.onDishSelect = this.onDishSelect.bind(this);
}
onDishSelect(dishId) {
this.setState({
selectedDish: dishId
});
}
render() {
return (
<div>
<Navbar dark color="primary">
<div className="container">
<NavbarBrand href="/">Ristorante Con Fusion</NavbarBrand>
</div>
</Navbar>
<Menu dishes={this.state.dishes} onClick={(dishId) => this.onDishSelect(dishId)} />
<Dishdetail selectedDish={this.state.dishes.filter((dish) => dish.id === this.state.selectedDish)[0]} />
</div>
);
}
}
export default Main;
DishDetail Component
import React, { Component } from 'react';
import { Card, CardImg, CardText, CardBody, CardTitle } from 'reactstrap';
export default class Dishdetail extends React.Component {
constructor(props) {
super(props);
}
renderDish(dish) {
if (dish != null)
return (
<Card >
<CardImg width="100%" src={dish.image} alt={dish.name} />
<CardBody>
<CardTitle>{dish.name}</CardTitle>
<CardText>{dish.description}</CardText>
</CardBody>
</Card>
);
else
return (
<div></div>
);
}
renderComments(comments) {
let list = (<div></div>);
if (comments != null) {
list = (
<ul className="list-unstyled">
{comments.map(c => {
return (
<li key={c.id}>
<p>{c.comment}</p>
<p>-- {c.author}, {new Intl.DateTimeFormat('en-US', { year: 'numeric', month: 'short', day: '2-digit' }).format(new Date(Date.parse(c.date)))}</p>
</li>
);
})}
</ul>
);
}
return (
<div>
<h4>Comments</h4>
{list}
</div>
);
}
render() {
return (
<div className="row">
<div className="col-12 col-md-5 m-1">
{this.renderDish(this.props.selectedDish)}
</div>
<div className="col-12 col-md-5 m-1">
{/* This works: */}
{ this.props.selectedDish && this.renderComments(this.props.selectedDish.comments)}
{/* This doesn't: */}
{/* { this.renderComments(this.props.selectedDish.comments)} */}
</div>
</div>
);
}
}
When your main component renders for the first time the props are still undefined as DISHES haven't been loaded, reasons for that might be the DISHES are initiated with some external resource.
So when this.props.selectedDish is undefined you can't access it's key because they don't exist. So react throws this error.
{ this.props.selectedDish && this.renderComments(this.props.selectedDish.comments)}
So this ensures this.props.selectedDish exists and then you are accessing it's comments key.
When your component is loaded the first time the selectedDish state value is null. It only gets set later, hence the error.
Changing the below code
constructor() {
super();
this.state = {
dishes: DISHES,
selectedDish: null
};
// this.onDishSelect = this.onDishSelect.bind(this);
}
To
constructor() {
super();
this.state = {
dishes: DISHES,
selectedDish: {}
};
// this.onDishSelect = this.onDishSelect.bind(this);
}
will make it work. However I feel that what you are doing now i.e. null check and then render is a more robust way of doing it.
Just a few pointers , you don't need to have a class based component since you aren't using lifecycle methods etc.
you can use destructuring to reduce typing
let {selectedDish:{comments}} = this.props .
You could solve your problem with a default value for comments ,
`const Dishdetail = ({selectedDishes:{comments}}=[]}) => {}
and conditional rendering in render
<div>
{ comments.length > 0 &&
//map you comments here if you have some
}
</div>`
I have created one child component and one parent component the child component gets called in from loop and event handlers also get called from prop but when i click on navlink from child component every click event is called
if first navlink is called then only handler for first navlink should be called.
import { NavLink } from "react-router-dom";
import React, { Component } from "react";
import axios from "axios";
// import SearchComponent from "../Common/SearchComponent";
// import Navbar from "../Common/Navbar";
import { CompanyId } from "../../locales/global.json";
import CategoryComponent from "./CategoryComponent";
class CategoryPageComponent extends Component {
state = {
Categories: []
};
componentDidMount() {
if (this.state.Categories.length === 0) this.bindCategoryData();
}
onCategorySearch = e => {
if (this.state.Categories.length === 0 && e === "")
this.bindCategoryData(0);
};
bindCategoryData = () => {
var $this = this;
axios
.post(
"http://fstrumplifyml.azurewebsites.net/api/ApiCategory/GetCategories",
{
companyid: CompanyId,
languageid: 1
}
)
.then(function(response) {
$this.setState({
Categories: response.data.Data
});
});
};
UpdateSubCategories = (categories, categoryId) => {
console.log(categories);
};
renderCategoryComponent = category => {
return (
<CategoryComponent
Category={category}
OnUpdateSubCategories={this.UpdateSubCategories.bind(this)}
/>
);
};
render() {
return (
<React.Fragment>
{/* <Navbar /> */}
<section className="space--sm">
<div className="container">
{/* <SearchComponent onSearch={this.onCategorySearch} /> */}
<div className="row">
{this.state.Categories.map(this.renderCategoryComponent)}
</div>
</div>
</section>
</React.Fragment>
);
}
}
export default CategoryPageComponent;
import React, { Component } from "react";
import { NavLink } from "react-router-dom";
class CategoryComponent extends Component {
render() {
return (
<div className="masonry__item col-md-4 filter-computing">
<div className="product">
<NavLink
to={this.props.OnUpdateSubCategories(
this.props.Category.SubCategories,
this.props.Category.CategoryId
)}
>
<img
alt={this.props.Category.CategoryName}
className="ProductImage"
src={this.props.Category.ImageUrl}
/>
</NavLink>
<NavLink
className="block"
to={this.props.OnUpdateSubCategories(
this.props.Category.SubCategories,
this.props.Category.CategoryId
)}
>
<div>
<h5>{this.props.Category.CategoryName}</h5>
</div>
</NavLink>
</div>
</div>
);
}
}
export default CategoryComponent;
<NavLink
className="block"
to={this.props.OnUpdateSubCategories(
this.props.Category.SubCategories,
this.props.Category.CategoryId
)}
>
when you put a function call inside props, it will be called everytime when render() runs
you can use arrow functions in props
to={
()=>{this.props.OnUpdateSubCategories(
this.props.Category.SubCategories,
this.props.Category.CategoryId
)}
}
but a function instance will be created in every render
so it is better to create a function inside CategoryComponent
I have 2 components 1)Content 2)Pagination
When I click on view stats button (see in screenshot) rendermatchinfo() method gets called and it shows details of single match and also shows pagination which should not be shown. Pagination must be shown only on home page where content component renders match details of all matches and not single match.
content.js :
import React, { Component } from 'react';
import Matchinfo from './matchinfo';
import './content.css';
class Content extends Component {
constructor(props){
super(props);
this.state = {
matches:[],
loading:true,
callmatchinfo: false,
matchid:''
};
}
componentDidMount(){
fetch('api/matches')
.then(res => res.json())
.then(res => {
console.log(res)
this.setState({
matches:res,
loading:false
});
})
}
viewstats(matchid){
this.setState({
callmatchinfo: true,
matchid: matchid
});
}
rendermatchinfo(){
return <Matchinfo matchid={this.state.matchid} />
}
renderMatches() {
return this.state.matches.slice(this.props.start, this.props.end).map(match => {
return (
<div className="col-lg-3">
<div id="content">
<p className="match">MATCH {match.id}</p>
<h4>{match.team1}</h4>
<p>VS</p>
<h4>{match.team2}</h4>
<div className="winner">
<h3>WINNER</h3>
<h4>{match.winner}</h4>
</div>
<div className="stats">
<button type="button" onClick= {()=>{this.viewstats(match.id)}} className="btn btn-success">View Stats</button>
</div>
</div>
</div>
);
})
}
render() {
if (this.state.loading) {
return <div>Loading...</div>
}
else if(this.state.callmatchinfo){
return <Matchinfo match_id={this.state.matchid} />
}
return (
<div>
<div className="row">
{this.renderMatches()}
</div>
<div className="row">
{this.state.callmatchinfo ? this.rendermatchinfo() : ''}
</div>
</div>
);
}
}
export default Content;
pagination.js:
import React, { Component } from 'react';
class Pagination extends Component {
handleClick(val){
this.setState({
end:val*16,
start:end-16
});
const end = val*16;
this.props.onChange(end - 16, end);
}
render() {
return (
<div>
<div className="container">
<ul className="pagination">
<li><a href="#" onClick={this.handleClick.bind(this, 1)}>1</a></li>
<li><a href="#" onClick={this.handleClick.bind(this, 2)}>2</a></li>
<li><a href="#" onClick={this.handleClick.bind(this, 3)}>3</a></li>
<li><a href="#" onClick={this.handleClick.bind(this, 4)}>4</a></li>
<li><a href="#" onClick={this.handleClick.bind(this, 5)}>5</a></li>
</ul>
</div>
</div>
);
}
}
export default Pagination;
Pagination and content component are imported in layout component.
layout.js :
import React, { Component } from 'react';
import Pagination from './pagination';
import Content from './content';
class Layout extends Component {
constructor(props){
super(props);
this.state = {
start:0,
end:16,
};
}
onChangePagination = (start, end) => {
this.setState({
start,
end
});
};
render() {
const {start, end} = this.state;
return (
<div>
<Content start={start} end={end}/>
<Pagination onChange={this.onChangePagination}/>
</div>
);
}
}
export default Layout;
Screenshot:
Home page which shows pagination :
When I click on view stats button of any particular match it still shows pagination but it should not show it.
move Pagination to Content component
Layout.js
import React, { Component } from 'react';
import Content from './content';
class Layout extends Component {
render() {
return (
<div>
<Content />
</div>
);
}
}
export default Layout;
Content.js
import React, { Component } from 'react';
import Matchinfo from './matchinfo';
import './content.css';
import Pagination from './pagination';
class Content extends Component {
constructor(props) {
super(props);
this.state = {
matches: [],
loading: true,
callmatchinfo: false,
matchid: '',
start: 0,
end: 16,
};
}
componentDidMount() {
fetch('api/matches')
.then(res => res.json())
.then(res => {
console.log(res)
this.setState({
matches: res,
loading: false
});
})
}
onChangePagination = (start, end) => {
this.setState({
start,
end
});
};
viewstats(matchid) {
this.setState({
callmatchinfo: true,
matchid: matchid
});
}
rendermatchinfo() {
return <Matchinfo matchid={this.state.matchid} />
}
renderMatches() {
return this.state.matches.slice(this.state.start, this.state.end).map(match => {
return (
<div className="col-lg-3">
<div id="content">
<p className="match">MATCH {match.id}</p>
<h4>{match.team1}</h4>
<p>VS</p>
<h4>{match.team2}</h4>
<div className="winner">
<h3>WINNER</h3>
<h4>{match.winner}</h4>
</div>
<div className="stats">
<button type="button" onClick={() => { this.viewstats(match.id) }} className="btn btn-success">View Stats</button>
</div>
</div>
</div>
);
})
}
render() {
if (this.state.loading) {
return <div>Loading...</div>
}
else if (this.state.callmatchinfo) {
return <Matchinfo match_id={this.state.matchid} />
}
return (
<div>
<div className="row">
{this.renderMatches()}
{!this.state.callmatchinfo && <Pagination onChange={this.onChangePagination} />}
</div>
<div className="row">
{this.state.callmatchinfo ? this.rendermatchinfo() : ''}
</div>
</div>
);
}
}
export default Content;
You should remove Pagination component from Layout component. Content component can be renamed as Matches component. Within the Matches component, show the Pagination component.
When view stat is clicked, show the MatchInfo component and hide the Matches and Pagination component.
I have created 3 components:
content
matchinfo
layout
pagination
Whenever I click on view stats button matchinfo component view is rendered which displays matchinfo of particular match. Whenever I click on view stats button (see screenshot) it also renders pagination component also which should not be rendered how can I fix this.
Component matchinfo is child component of content component.
content.js :
import React, { Component } from 'react';
import Matchinfo from './matchinfo';
import './content.css';
class Content extends Component {
constructor(props){
super(props);
this.state = {
matches:[],
loading:true,
callmatchinfo: false,
matchid:''
};
}
componentDidMount(){
fetch('api/matches')
.then(res => res.json())
.then(res => {
console.log(res)
this.setState({
matches:res,
loading:false
});
})
}
viewstats(matchid){
this.setState({
callmatchinfo: true,
matchid: matchid
});
}
rendermatchinfo(){
return <Matchinfo matchid={this.state.matchid} />
}
renderMatches() {
return this.state.matches.slice(this.props.start, this.props.end).map(match => {
return (
<div className="col-lg-3">
<div id="content">
<p className="match">MATCH {match.id}</p>
<h4>{match.team1}</h4>
<p>VS</p>
<h4>{match.team2}</h4>
<div className="winner">
<h3>WINNER</h3>
<h4>{match.winner}</h4>
</div>
<div className="stats">
<button type="button" onClick= {()=>{this.viewstats(match.id)}} className="btn btn-success">View Stats</button>
</div>
</div>
</div>
);
})
}
render() {
if (this.state.loading) {
return <div>Loading...</div>
}
else if(this.state.callmatchinfo){
return <Matchinfo match_id={this.state.matchid} />
}
return (
<div>
<div className="row">
{this.renderMatches()}
</div>
<div className="row">
{this.state.callmatchinfo ? this.rendermatchinfo() : ''}
</div>
</div>
);
}
}
export default Content;
matchinfo.js :
import React, { Component } from 'react';
class Matchinfo extends Component {
constructor(props){
super(props);
this.state = {
info:[],
loading:true
};
}
componentWillMount(){
fetch(`api/match/${this.props.match_id}`)
.then(res => res.json())
.then(res => {
console.log(res)
this.setState({
info:res,
loading:false
})
})
}
render() {
if (this.state.loading) {
return <div>Loading...</div>
}
const {info} = this.state;
return (
<div>
<p className="match">MATCH {info.id}</p>
<h4>{info.team1}</h4>
<p>VS</p>
<h4>{info.team2}</h4>
<div className="winner">
<h3>WINNER</h3>
<h4>{info.winner}</h4>
</div>
</div>
);
}
}
export default Matchinfo;
pagination.js :
import React, { Component } from 'react';
class Pagination extends Component {
handleClick(val){
this.setState({
end:val*16,
start:end-16
});
const end = val*16;
this.props.onChange(end - 16, end);
}
render() {
return (
<div>
<div className="container">
<ul className="pagination">
<li><a href="#" onClick={this.handleClick.bind(this, 1)}>1</a></li>
<li><a href="#" onClick={this.handleClick.bind(this, 2)}>2</a></li>
<li><a href="#" onClick={this.handleClick.bind(this, 3)}>3</a></li>
<li><a href="#" onClick={this.handleClick.bind(this, 4)}>4</a></li>
<li><a href="#" onClick={this.handleClick.bind(this, 5)}>5</a></li>
</ul>
</div>
</div>
);
}
}
export default Pagination;
layout.js :
import React, { Component } from 'react';
import Pagination from './pagination';
import Content from './content';
class Layout extends Component {
constructor(props){
super(props);
this.state = {
start:0,
end:16
};
}
onChangePagination = (start, end) => {
this.setState({
start,
end
});
};
render() {
const {start, end} = this.state;
return (
<div>
<Content start={start} end={end}/>
<Pagination onChange={this.onChangePagination}/>
</div>
);
}
}
export default Layout;
Screenshots:
Onclick view stats button it still shows pagination:
You should approach toggling pagination the same way you did for showing match information. Hold a variable in this.state for your Layout component and make a method that will control that this.state variable. Pass that method down to your child component. Here is a barebones example:
class Layout extends Component {
constructor(props){
super(props);
this.state = {
showPagination: true
}
}
onChangePagination = () => {
this.setState({showPagination: !this.state.showPagination}) //toggles pagination
};
render() {
return (
<div>
{
this.state.showPagination
?
<Pagination onChangePagination={this.onChangePagination}/>
:
<button onClick={this.onChangePagination}>
show pagination
</button>
}
</div>
)
}
}
class Pagination extends Component {
handleClick() {
this.props.onChangePagination()
}
render() {
return (
<div>
<button onClick={this.handleClick}>
toggle pagination
</button>
</div>
)
}
}
I am trying to implement the following: https://www.npmjs.com/package/react-sticky
in my code as follow:
import React from 'react';
import Video from './../video.jsx';
import Overview from './overview.jsx';
import Photography from './photography.jsx';
import Details from './details.jsx';
import Cast from './cast.jsx';
import porgectsCollection from './../../data/projectInfo.js';
import { StickyContainer, Sticky } from 'react-sticky';
class Nav extends React.Component {
constructor(props) {
super(props);
this.state = {
mobileMenu: false
};
}
showMobileMenu () {
this.setState({ mobileMenu: !this.state.mobileMenu });
}
render () {
let links = this.props.project.links.map(function(el, i){
return <li key={i}>{el}</li>;
});
const open = this.state.mobileMenu ? ' open' : '';
return (
<StickyContainer>
<span onClick={this.showMobileMenu.bind(this)} className="mobile-trigger">X</span>
<Sticky topOffset={100} stickyClassName="sticky-nav">
<nav className={"secondary-nav" + open}>
<ul>
{links}
</ul>
</nav>
</Sticky>
</StickyContainer>
);
}
}
class SingleProject extends React.Component {
getProjectDataFromUrl() {
return porgectsCollection.filter(el => el.title === this.props.params.id);
}
render () {
let data = this.getProjectDataFromUrl(),
project = data[0];
console.log(project);
return (
<section className="project-page">
<Video project={project} />
<Nav project={project} />
<Overview project={project} />
<Photography project={project} />
<Details project={project} />
<Cast project={project} />
</section>
);
}
}
export default SingleProject;
I would hope that when "Sticky" reached 100px from the top it would get a custom class "sticky-nav" applied to it. However the nav keeps on scrolling without getting stuck at all. I can see the divs applied around my markup with the extra padding but no more then that.
URL project: https://github.com/WebTerminator/aldemar,
file in question is singleProject.jsx
import React from 'react';
import Video from './../video.jsx';
import Overview from './overview.jsx';
import Photography from './photography.jsx';
import Details from './details.jsx';
import Cast from './cast.jsx';
import porgectsCollection from './../../data/projectInfo.js';
import { StickyContainer, Sticky } from 'react-sticky';
class Nav extends React.Component {
constructor(props) {
super(props);
this.state = {
mobileMenu: false
};
}
showMobileMenu () {
this.setState({ mobileMenu: !this.state.mobileMenu });
}
render () {
let links = this.props.project.links.map(function(el, i){
return <li key={i}>{el}</li>;
});
const open = this.state.mobileMenu ? ' open' : '';
return (
<Sticky stickyClassName="sticky-nav" topOffset={-100}>
<span onClick={this.showMobileMenu.bind(this)} className="mobile-trigger">X</span>
<nav className={"secondary-nav" + open}>
<ul>
{links}
</ul>
</nav>
</Sticky>
);
}
}
class SingleProject extends React.Component {
getProjectDataFromUrl() {
return porgectsCollection.filter(el => el.title === this.props.params.id);
}
render () {
let data = this.getProjectDataFromUrl(),
project = data[0];
return (
<section className="project-page">
<StickyContainer>
<Video project={project} />
<Nav project={project} />
<Overview project={project} />
<Photography project={project} />
<Details project={project} />
<Cast project={project} />
</StickyContainer>
</section>
);
}
}
export default SingleProject;