Develop Reference

properties.map is not a function when map

I'm getting the error "TypeError: properties.map is not a function", however when i console.log(properties) i can see the data. Can anyone explain me what i'm doing wrong?
If i remove the map code obviously the error is not showing. Is it because "properties" is not defined yet during the render? I'm a bit confused of why it's not defined since as i said i can see the data on load with the console.
import React, { Component } from 'react';
import { useDispatch, useSelector } from 'react-redux';
import { AndroidOutlined, AppleOutlined } from '#ant-design/icons';
import Tabs, { TabPane } from '#iso/components/uielements/tabs';
import Select, { SelectOption } from '#iso/components/uielements/select';
import Button from '#iso/components/uielements/button';
import PageHeader from '#iso/components/utility/pageHeader';
import Box from '#iso/components/utility/box';
import { Form, Input, Checkbox, Col, Row } from 'antd'
import LayoutWrapper from '#iso/components/utility/layoutWrapper.js';
import ContentHolder from '#iso/components/utility/contentHolder';
import IntlMessages from '#iso/components/utility/intlMessages';
import FormGeneral from './FormGeneral';
import FormDetails from './FormDetails';
import propertiesActions from '#iso/redux/properties/actions';
const Option = SelectOption;
const {
loadFromApi,
} = propertiesActions;
export default function PropertiesPage() {
const dispatch = useDispatch();
React.useEffect(() => {
dispatch(loadFromApi());
}, [dispatch]);
const { properties, property, isLoading } = useSelector(
state => state.Properties
);
const rowStyle = {
width: '100%',
display: 'flex',
flexFlow: 'row wrap',
};
const colStyle = {
marginBottom: '16px',
};
const gutter = 16;
// Show data
console.log(properties);
console.log(isLoading);
return (
<LayoutWrapper>
<PageHeader>Properties</PageHeader>
<Box>
<Tabs defaultActiveKey="1">
<TabPane
tab={
<span>
<AppleOutlined />
General
</span>
}
key="1"
>
<div>
{console.log(properties)}
{properties.map(e =>
<div key={e.id}>
{e.id}
</div>
)}
</div>
<Row style={rowStyle} gutter={gutter} justify="start">
<Col md={12} sm={12} xs={24} style={colStyle}>
<Box>
<FormGeneral />
</Box>
</Col>
</Row>
</TabPane>
<TabPane
tab={
<span>
<AndroidOutlined />
Tab 2
</span>
}
key="2"
>
<FormDetails />
</TabPane>
</Tabs>
</Box>
</LayoutWrapper>
);
}
UPDATED:
properties is empty object at first

What if you try properties?.map, so it doesn't map if it is undefined, and wait until you really get the array. Because I don't have a big knowledge about redux, but from what I can read from your code, I understand that you are getting the properties asynchronously.

By default properties is undefined. .map cannot work with undefined. Try to use:
const { properties = [], property, isLoading } = useSelector(
state => state.Properties
);
It is possible to extend the answer and change the initialState, but your reducer code is needed.

before you map properties you should check if it is undefined because the initial value of state object in react is undefined and I think that if you will roll up in your console you should see an undefined print to the console
<div>
{console.log(properties)}
{properties !== undefined ? properties.map(e =>
<div key={e.id}>
{e.id}
</div>
): null}
</div>

In fact the object was defined but empty, i had to check for the length
<div>
{console.log(properties)}
{properties.length > 1 ? properties.map(e =>
<div key={e.id}>
{e.id}
</div>
): null}
</div>
Doing this resolved the issue.

React Router history.push in infinite loop

I have a page ("/paymentsucess"). In this page, I am using the react-countdown-circle-timer component (https://github.com/vydimitrov/react-countdown-circle-timer#props-for-both-reactreact-native). Upon reaching this page ("/paymentsuccess"), countdown beings. After countdown reaches zero, I want to redirect user back to home page ("/").
To achieve this, for the CountdownCircleTimer component, when onComplete, I set the state initialMount to false.
<CountdownCircleTimer
onComplete={() => {
setInitialMount(false);
return [true, 1500];
}}
isPlaying
duration={2}
colors={[
["#004777", 0.33],
["#F7B801", 0.33],
["#A30000", 0.33],
]}
>
{renderTime}
</CountdownCircleTimer>
Given that initialMount is changed, my useEffect (in the paymentsuccess component) will kick in and redirect users to "/". I am using history.push("/") here.
useEffect(() => {
if (initialMount !== true) {
console.log("On change in status,");
console.log(initialMount);
history.push("/");
}
}, [initialMount, history]);
I was able to redirect user back to "/" successfully. But upon reaching "/", they got redirected back to /paymentsuccess again. And then from /paymentsuccess it goes back to / and then the loops continue. Infinite loop.
Any idea what I am doing wrong here? :( I need to stop this loop and lands user back to / and stops there.
I am using Router from react-router-dom and createBrowserHistory from history.
Below is the full code for my paymentsuccess component
import React, { useEffect, useStatem} from "react";
import { useHistory } from "react-router-dom";
import { makeStyles } from "#material-ui/core/styles";
import Grid from "#material-ui/core/Grid";
import Paper from "#material-ui/core/Paper";
import { CountdownCircleTimer } from "react-countdown-circle-timer";
function PaymentSuccess() {
const useStyles = makeStyles((theme) => ({
root: {
flexGrow: 1,
},
}));
const classes = useStyles();
const history = useHistory();
const [initialMount, setInitialMount] = useState(true);
useEffect(() => {
console.log("On component mount, status is");
console.log(initialMount);
}, []);
useEffect(() => {
return () => {
console.log("On component unmount, status is");
setInitialMount(true);
console.log(initialMount);
};
}, []);
useEffect(() => {
if (initialMount !== true) {
console.log("On change in status,");
console.log(initialMount);
history.push("/");
}
}, [initialMount, history]);
const renderTime = ({ remainingTime }) => {
if (remainingTime === 0) {
return <div className="timer">Starting...</div>;
}
return (
<div className="timer">
<div className="value">{remainingTime}</div>
</div>
);
};
return (
<div className={classes.root}>
<Grid container spacing={0}>
<Grid item xs={6} sm={6}>
<Paper
className="paymentSuccessLeftPaper"
variant="outlined"
square
></Paper>
</Grid>
<Grid item xs={6} sm={6}>
<Paper className="paymentSuccessRightPaper" variant="outlined" square>
<h1>Payment Success</h1>
<CountdownCircleTimer
onComplete={() => {
setInitialMount(false);
return [true, 1500];
}}
isPlaying
duration={2}
colors={[
["#004777", 0.33],
["#F7B801", 0.33],
["#A30000", 0.33],
]}
>
{renderTime}
</CountdownCircleTimer>
</Paper>
</Grid>
</Grid>
</div>
);
}
export default PaymentSuccess;
I have checked my "/" page and I don't think there is any logic there redirecting to "/paymentsuccess". The page ("/") code is as below.
import React from "react";
import { makeStyles } from "#material-ui/core/styles";
import Grid from "#material-ui/core/Grid";
import Paper from "#material-ui/core/Paper";
import Button from "#material-ui/core/Button";
import Link from "#material-ui/core/Link";
function LandingPage() {
const useStyles = makeStyles((theme) => ({
root: {
flexGrow: 1,
},
paper: {
minHeight: "100%",
padding: theme.spacing(0),
textAlign: "center",
color: theme.palette.text.secondary,
},
}));
const classes = useStyles();
return (
<div className={classes.root}>
<Grid container spacing={0}>
<Grid item xs={4} sm={4}>
<Paper className={classes.paper} variant="outlined" square>
<h1>Photo Strips</h1>
<Button variant="contained" color="primary">
<Link href="/photo10">SELECT</Link>
</Button>
</Paper>
</Grid>
<Grid item xs={4} sm={4}>
<Paper className={classes.paper} variant="outlined" square>
<h1>Photo Strips and GIF</h1>
<Button variant="contained" color="primary">
<Link href="/photogif12">
SELECT
</Link>
</Button>
</Paper>
</Grid>
<Grid item xs={4} sm={4}>
<Paper className={classes.paper} variant="outlined" square>
<h1>Photo Strips and Boomerang</h1>
<Button variant="contained" color="primary">
<Link href="/photoboomerang12">
SELECT
</Link>
</Button>
</Paper>
</Grid>
</Grid>
</div>
);
}
export default LandingPage;
Thank you all in advance! Appreciate all the help and advise
UPDATE
Below is Router code
import React from "react";
import { Router, Switch } from "react-router-dom";
import LandingPage from "./components/LandingPage";
import Photo10 from "./components/Photo10";
import PhotoGIF12 from "./components/PhotoGIF12";
import PhotoBoomerang12 from "./components/PhotoBoomerang12";
import PaymentSuccess from "./components/PaymentSuccess";
import DynamicLayout from "./router/DynamicLayout";
import { history } from "./helpers/history";
const App = () => {
return (
<Router history={history}>
<div className="App">
<Switch>
<DynamicLayout
exact
path="/"
component={LandingPage}
layout="LANDING_NAV"
/>
<DynamicLayout
exact
path="/photo10"
component={Photo10}
layout="PHOTO10_PAGE"
/>
<DynamicLayout
exact
path="/photogif12"
component={PhotoGIF12}
layout="PHOTOGIF12_PAGE"
/>
<DynamicLayout
exact
path="/photoboomerang12"
component={PhotoBoomerang12}
layout="PHOTOBOOMERANG12_PAGE"
/>
<DynamicLayout
exact
path="/paymentsuccess"
component={PaymentSuccess}
layout="PAYMENTSUCCESS_PAGE"
/>
</Switch>
</div>
</Router>
);
};
export default App;
Below is the code for the DynamicLayout component
import React from "react";
const DynamicLayout = (props) => {
const { component: RoutedComponent, layout } = props;
const actualRouteComponent = <RoutedComponent {...props} />;
switch (layout) {
case "LANDING_NAV": {
return <>{actualRouteComponent}</>;
}
case "PHOTO10_PAGE": {
return <>{actualRouteComponent}</>;
}
case "PHOTOGIF12_PAGE": {
return <>{actualRouteComponent}</>;
}
case "PHOTOBOOMERANG12_PAGE": {
return <>{actualRouteComponent}</>;
}
case "PAYMENTSUCCESS_PAGE": {
return <>{actualRouteComponent}</>;
}
default: {
return (
<>
<h2>Default Nav</h2>
{actualRouteComponent}
</>
);
}
}
};
export default DynamicLayout;

This problem occurs when you changes value of variable in useEffect and that variable also added in useEffect dependency array, So when ever your useEffect change the value due to presence of that variable in dependency array, it again called the useEffect thus a infinite loop occurs
so just remove 'history' variable from your dependency array

props are passed but are undefined when they are mapped

When I map the array directly, I don't face any error but if I pass the same array through props, I face the error that "Cannot read property 'map' of undefined"
brands array
const brands = [
{
key: 1,
Name: "Nike",
},
{
key: 2,
Name: "Adidas",
},
{
key: 3,
Name: "Apollo",
},
{
key: 4,
Name: "Puma",
},
];
export default brands;
Parent Component
import React from "react";
import { Button, Checkbox } from "#material-ui/core";
import SimpleAccordion from "./simpleAccordion";
import "./Sidebar.css";
import brands from "./BrandNames";
function App() {
console.log("I am in App component", brands);
return (
<React.Fragment>
<div className="sidenav">
<SimpleAccordion children="Categories" brands={brands} /> // here passing the props as brands
<hr style={{ color: "#999999" }} />
{/* <h1>Helooooooo</h1>
{brands.forEach((brand) => {
return <span>{brand.Name}</span>;
})} */}
{brands.map((brand, key) => {
return (
<div>
<h1>{brand.Name}</h1>
<h1>{brand.key}</h1>
</div>
);
})}
<h1>Helooooooo</h1>
<SimpleAccordion children="Brands" />
<hr style={{ color: "#999999" }} />
<SimpleAccordion children="Stores" />
<hr style={{ color: "#999999" }} />
<SimpleAccordion children="Price" />
</div>
</React.Fragment>
);
}
export default App;
Child Component
import React,{useState} from 'react';
import Accordion from '#material-ui/core/Accordion';
import AccordionSummary from '#material-ui/core/AccordionSummary';
import AccordionDetails from '#material-ui/core/AccordionDetails';
import Typography from '#material-ui/core/Typography';
import AddIcon from '#material-ui/icons/Add';
import CloseIcon from '#material-ui/icons/Close';
import {Checkbox} from '#material-ui/core';
import brands from './BrandNames';
export default function SimpleAccordion(props) {
const[iconName,setIcon]= useState(false);
function handleClick(){
setIcon(!iconName);
}
// shows data at first time but then becomes undefine
console.log("here", props.brands)
return (
<React.Fragment>
// Directly mapping the (imported)"brands" array, no error
{brands.map((brand, key) => {
return (
<div>
<h1>{brand.Name}</h1>
<h1>{brand.key}</h1>
</div>
);
})}
// mapping props.brands array and there are errors.
{props.brands.map((brand, key) => {
return (
<div>
<h1>{brand.Name}</h1>
<h1>{brand.key}</h1>
</div>
);
})}
<Accordion style={{boxShadow:"0px 0px 0px "}} >
<AccordionSummary expandIcon={iconName ? <CloseIcon /> : <AddIcon/>} onClick={handleClick}>
<Typography style={{color:"#333333",fontWeight:"bolder"}}>{props.children}</Typography >
</AccordionSummary>
<AccordionDetails >
<Typography>
</Typography>
</AccordionDetails>
</Accordion>
</React.Fragment>
);
}
If I don't use the props in the child component, it works fine. brands.map works fine but when props are used, props.brands give the errors i.e TypeError: Cannot read property 'map' of undefined. Why are the props giving me the errors...

I was rendering more than one SimpleAccordion component but only passing props to the first component. That's why the props were undefined when mapped as other components were not given the props.

How to render React component with passed in props on click

I am making a Menu using React and Redux but am currently having an issue rendering the items when the user selects a category.
My goal is to render a list of items nested in the redux state of a particular category when it is clicked.
In Categories.js, it loads the categories from the redux store and displays them.
import React, { Component } from "react";
import { connect } from "react-redux";
import CategoryItems from "./CategoryItems"
import {
Card,
CardTitle,
CardImg,
Container,
Row,
Col,
CardBody,
Button
} from "shards-react";
class Categories extends Component {
handleClick = category => {
alert(category.title);
return (
<CategoryItems
category={category}
/>
);
};
render() {
let categoryList = this.props.categories.map(category => {
return (
<div key={category.id}>
<Col>
<Card
key={category.id}
onClick={() => {
this.handleClick(category);
}}
>
<CardBody>
<CardTitle>{category.title}</CardTitle>
</CardBody>
</Card>
</Col>
</div>
);
});
return (
<Container>
<Row>{categoryList}</Row>
</Container>
);
}
}
const mapStateToProps = state => {
return {
categories: state.categories,
};
};
export default connect(mapStateToProps)(Categories);
When a category is clicked, (the alert was just so I could make sure data made it) I have it set to render the items Array nested within the selected category.
import React, { Component } from 'react'
import {
Card,
CardTitle,
CardImg,
Container,
Row,
Col,
CardBody,
Button
} from "shards-react";
export class CategoryItems extends Component {
render() {
let items = this.props.category.items;
let categoryItems = items.map(item => {
return (
<Col className="">
<Card
className="mt-2 mb-2 item-col"
style={{ maxWidth: "500px" }}
key={item.id}
>
<CardBody>
<CardTitle style={{ position: "absolute", top: 20, right: 20 }}>
{item.title}
</CardTitle>
<CardImg
style={{ maxWidth: "200px" }}
src={item.img}
alt={item.title}
/>
<span
style={{ position: "absolute", bottom: 40, right: 100 }}
to="/"
// onClick={() => {
// this.handleClick(item.id);
// }}
>
<Button pill theme="info">
+
</Button>
</span>
<div style={{ position: "absolute", bottom: 40, right: 20 }}>
${item.price}
</div>
</CardBody>
</Card>
</Col>
);
});
return (
<Container className="menu-item-cont">
<Row>{categoryItems}</Row>
</Container>
);
}
}
export default CategoryItems
This part does not render the items and I don't get an error message.
I have also tried placing the items I would like rendered directly into the state just to see if I could get them to render on click similar to how the Categories.js is with no luck.
I am somewhat new to react so please forgive me if this is a beginner question.
Any help is appreciated as I have spent hours trying to figure this out.

The problem is that you're not rendering what gets returned from handleClick. What you need is a conditional render in the JSX, then determine whether or not to render the elements depending on a controlled flag variable in the state.
class Categories extends Component {
constructor() {
this.state = {
show: false,
category: undefined
}
this.toggle = (category) => {
this.setState({ show: !this.state.show, category })
}
}
render() {
let categoryList = this.props.categories.map(category => {
return (
<div key={category.id}>
<Col>
<Card
key={category.id}
onClick={e => this.toggle(category)}
>
<CardBody>
<CardTitle>{category.title}</CardTitle>
</CardBody>
</Card>
</Col>
</div>
);
});
return ([
<Container>
<Row>{categoryList}</Row>
</Container>,
(
this.state.show
? <CategoryItems category={this.state.category}/>
: null
)
]);
}
}

React JS Sortable Form Fields as Components

I'm trying to develop a fairly simplistic E-Mail template creator with React JS. I'm using the "react-sortable-hoc" library as a means to handle the ordering of elements on the page.
The goal is to allow users to create "Rows", rearrange rows, and within each row, have multiple "Columns" that can contain components like images, textboxes, etc...
But I keep running into the same issue with Sortable libraries. Form fields cannot maintain their own "state" when being dragged up or down. The State of a Component in React JS seems to be lost when it's in a draggable component. I've experienced similar issues with JQuery UI's Sortable but it required an equally ridiculous solution. Is it common to find that form fields are simply super difficult to rearrange?
As a "proof of concept", I am using a complex JSON object that stores all the information in the Letter.js component and passes it down as Props which are then passed down to each component. But as you can tell, this is becoming cumbersome.
Here is an example of my Letter component that handles the JSON object and sorting of Rows:
import React, {Component} from 'react';
import {render} from 'react-dom';
import {
SortableContainer,
SortableElement,
arrayMove
} from 'react-sortable-hoc';
import Row from './Row';
const SortableItem = SortableElement(({row, rowIndex, onChange, addPart}) => {
return (
<li>
<Row
row={row}
rowIndex={rowIndex}
onChange={onChange}
addPart={addPart} />
</li>
)
});
const SortableList = SortableContainer(({rows, onChange, addPart}) => {
return (
<ul id="sortableList">
{rows.map((row, index) => {
return (
<SortableItem
key={`row-${index}`}
index={index}
row={row}
rowIndex={index}
onChange={onChange}
addPart={addPart}
/> )
})}
</ul>
);
});
class Letter extends Component {
constructor(props) {
super(props);
this.state = {
rows: [],
}
this.onSortEnd = this.onSortEnd.bind(this);
this.onChange = this.onChange.bind(this);
this.addRow = this.addRow.bind(this);
this.addPart = this.addPart.bind(this);
}
addPart(event, index, value, rowIndex, columnIndex) {
console.log(value);
var part = {};
if(value === 'Text') {
part = {
type: 'Text',
value: ''
}
} else if(value === 'Image') {
part = {
type: 'Image',
value: ''
}
} else {
part = {
type: 'Empty',
}
}
const { rows } = this.state;
rows[rowIndex][columnIndex] = part;
this.setState({ rows: rows })
}
onChange(text, rowIndex, columnIndex) {
const { rows } = this.state;
const newRows = [...rows];
newRows[rowIndex][columnIndex].value = text;
this.setState({ rows: newRows });
}
addRow(columnCount) {
var rows = this.state.rows.slice();
var row = [];
for(var i = 0; i < columnCount; i++) {
var part = {
type: 'Empty',
}
row.push(part);
}
rows.push(row);
this.setState({ rows: rows })
}
onSortEnd = ({oldIndex, newIndex}) => {
this.setState({
rows: arrayMove(this.state.rows, oldIndex, newIndex),
});
};
render() {
console.log(JSON.stringify(this.state.rows));
const SideBar = (
<div className="sideBar">
<h3>Add a Row</h3>
<button className="uw-button" onClick={() => this.addRow(1)}>1 - Column</button><br/><br/>
<button className="uw-button" onClick={() => this.addRow(2)}>2 - Column</button><br/><br/>
<button className="uw-button" onClick={() => this.addRow(3)}>3 - Column</button>
<hr />
</div>
);
if(this.state.rows.length <= 0) {
return (
<div className="grid">
<p>This E-Mail is currently empty! Add some components to make a template.</p>
{SideBar}
</div>
)
}
return (
<div className="grid">
<SortableList
rows={this.state.rows}
onChange={this.onChange}
addPart={this.addPart}
lockAxis="y"
useDragHandle={true}
onSortStart={this.onSortStart}
onSortMove={this.onSortMove}
onSortEnd={this.onSortEnd}
shouldCancelStart={this.shouldCancelStart} />
{SideBar}
</div>
);
}
}
export default Letter;
And here is an example of Row:
import React, { Component } from 'react';
import { Text, Image } from './components/';
import { SortableHandle } from 'react-sortable-hoc';
import MuiThemeProvider from 'material-ui/styles/MuiThemeProvider';
import { Card, CardActions, CardHeader, CardMedia, CardTitle, CardText } from 'material-ui/Card';
import DropDownMenu from 'material-ui/DropDownMenu';
import MenuItem from 'material-ui/MenuItem';
const DragHandle = SortableHandle(() => <span className="dragHandle"></span>);
class Row extends Component {
constructor(props) {
super(props);
}
render() {
if(this.props.row !== undefined && this.props.row.length > 0) {
const row = this.props.row.map((column, columnIndex) => {
if(column.type === 'Empty') {
return (
<MuiThemeProvider key={columnIndex}>
<div className="emptyColumn">
<Card>
<DragHandle />
<CardTitle title="Empty Component"/>
<DropDownMenu value={"Empty"} onChange={(event, index, value) => this.props.addPart(event, index, value, this.props.rowIndex, columnIndex)}>
<MenuItem value={"Empty"} primaryText="Empty" />
<MenuItem value={"Text"} primaryText="Textbox" />
<MenuItem value={"Image"} primaryText="Image" />
</DropDownMenu>
</Card>
</div>
</MuiThemeProvider>
)
} else if(column.type === 'Text') {
return (
<MuiThemeProvider key={columnIndex}>
<div className="textColumn">
<Card>
<DragHandle />
<CardTitle title="Textbox"/>
<DropDownMenu value={"Text"} onChange={(event, index, value) => this.props.addPart(event, index, value, this.props.rowIndex, columnIndex)}>
<MenuItem value={"Empty"} primaryText="Empty" />
<MenuItem value={"Text"} primaryText="Textbox" />
<MenuItem value={"Image"} primaryText="Image" />
</DropDownMenu>
<Text
value={this.props.row[columnIndex].value}
onChange={this.props.onChange}
columnIndex={columnIndex}
rowIndex={this.props.rowIndex} />
</Card>
</div>
</MuiThemeProvider>
)
} else if(column.type === 'Image') {
return (
<MuiThemeProvider key={columnIndex}>
<div className="textColumn">
<Card>
<DragHandle />
<CardTitle title="Image"/>
<DropDownMenu value={"Image"} onChange={(event, index, value) => this.props.addPart(event, index, value, this.props.rowIndex, columnIndex)}>
<MenuItem value={"Empty"} primaryText="Empty" />
<MenuItem value={"Text"} primaryText="Textbox" />
<MenuItem value={"Image"} primaryText="Image" />
</DropDownMenu>
<Image
columnIndex={columnIndex}
rowIndex={this.props.rowIndex} />
</Card>
</div>
</MuiThemeProvider>
)
}
})
return (
<div className="row">
{row}
</div>
)
}
return <p>No components</p>;
}
}
export default Row;
Lastly, this is what Text.js looks like
import React, { Component } from 'react';
import ReactQuill from 'react-quill';
class Text extends Component {
constructor(props) {
super(props);
}
render() {
return (
<ReactQuill value={this.props.value}
onChange={(text) => this.props.onChange(text, this.props.rowIndex, this.props.columnIndex)} />
)
}
}
export default Text;
So, I keep having to pass ridiculous parameters to onChange functions and other functions in order to ensure that the state is maintained while sorting and editing. So, how should I be handling this? I don't want Letter.js (which is basically App.js) to handle all of my data handling. I want each component to handle it's own. I want Text.js to handle the onChange effects of its text. But I just can't see a way around passing everything down as props.