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How to pass data(count) from Quantity component to Mainpart component using lifting state up in react

Quantity component is my child class and Mainpart component is my parent class.i want to use my (count) in my parent class.but i dont know how to pass that data.sorry my english is not good.i think you will get the idea.
const MainPart = () => {
const submit = (event) => {
debugger;
event.preventDefault();
}
return (
<div>
<form onSubmit={submit}>
<Container>
<Row>
<Col sm={4}>
<Picture image='../images/test.jpg' alt='tent' />
</Col>
<Col sm={8}>
<Title title='4 Person tent' itemNo='Item No. MA000001' />
<Currency mark='$' price='150.00' />
<Quantity />
<div style={{ marginTop: '5%', textAlign: 'center' }}>
<input type='submit' value='ADD TO CART' style={{ backgroundColor: 'yellow', padding: '5px 5px 5px 5px' }} />
</div>
</Col>
</Row>
</Container>
</form>
</div>
);
};
--------------------------------------------------------------------------------------------------
const Quantity = (props) => {
const [count, setCount] = useState(0);
const increaseClick = () => {
setCount(count + 1 )
}
const decreaseClick = () => {
setCount(count - 1 )
}
return (
<>
<div style={{ display: 'flex', marginTop: '5%', marginLeft: '30%' }}>
<Button variant="primary" style={{ marginRight: '5%' }} onClick={decreaseClick}>-</Button>
<h3>{count}</h3>
<Button variant="primary" style={{ marginLeft: '5%' }} onClick={increaseClick}>+</Button>
</div>
</>
);
};

You have to create your state in parent and then pass to child, it will work.
const MainPart = () => {
const [count, setCount] = useState(0);
return (
...Your rest of code.
<Quantity count={count} setCount={setCount} />
)
}
Then In your child component, Use like this:
const Quantity = ({ count, setCount }) => {
const increaseClick = () => {
setCount(count + 1 )
}
const decreaseClick = () => {
setCount(count - 1 )
}
return (
<>
<div style={{ display: 'flex', marginTop: '5%', marginLeft: '30%'
}}>
<Button variant="primary" style={{ marginRight: '5%' }} onClick={decreaseClick}>-</Button>
<h3>{count}</h3>
<Button variant="primary" style={{ marginLeft: '5%' }} onClick={increaseClick}>+</Button>
</div>
</>
);
}

Why doesn't my image show on my react app page?

So i've been trying to show an image on my page with an API, but everytime I go to the page I see the image for a few seconds and after that the page refreshes and it shows an error:
Uncaught TypeError: location is undefined
I think the problem could be about the way I used my image, but i am not sure. If I console log the image it just shows the correct image name. This is the code I used:
import { Row, Col } from "react-grid-system";
import { Separator } from "#fluentui/react";
import * as React from "react";
import { useEffect, useState } from "react";
function Recipe(props) {
const axios = require('axios');
const api = axios.create({
baseURL: 'http://localhost:5000/',
timeout: 10000
})
const [recipe, setRecipe] = useState({});
const [image, setImage] = useState({});
useEffect(() => {
getRecipe()
}, [])
function getRecipe() {
api.get('/recipe/' + props.id).then(res => {
setRecipe(res.data);
setImage("https://localhost:5001/Uploads/" + res.data.image)
});
}
return (
<div>
<div>
<Row>
<Col sm={6} md={6} lg={6}>
<img style={{ width: "700px", marginTop: "20px" }} src={image} alt={"error"} />
</Col>
<Col style={{ marginTop: "20px" }} sm={6} md={6} lg={6}>
<Separator className={"Separator"} />
<h1>Naam: <div style={{ fontSize: "20px" }}>{recipe.name}</div></h1>
<h1>Ingredienten: <div style={{ fontSize: "20px" }}> {recipe.ingredients}</div>
</h1>
<h1>Macro's:
<div style={{ fontSize: "20px" }}>
<ul>
<li>Kcal: {recipe.carbs}</li>
</ul>
</div>
</h1>
<h1>Voorbereiding: <div style={{ fontSize: "12px" }}>
{recipe.preparation} </div></h1>
</Col>
</Row>
</div>
</div>
)
}
export default Recipe

How to scrollToView for a specific item in an array

I have a component that scrolls to view after a comment has been submitted.
const commentSubmit = (e: any, id: number) => {
......
divRef.current.scrollIntoView({ behavior: "smooth" });
};
It scrolls to the comment where <div ref={divRef]></div> is placed which is at the bottom of the most recent comment. The probelem is that if i make a new post, it will scroll into the wrong div element. So its just scrolling at the very bottom. How can i tell ref to scroll to the a specific element based on what post the comment belongs to ?
{post.Comments.length > 0 ? (
<Fragment>
<Typography style={{ padding: "10px 0px", margin: "20px 0px" }}>Commments</Typography>
// ignore this divRef in comment list its not being called in the comment list.
<CommentList ref={divRef} user={currentUser} deleteComment={props.deleteComment} userId={post.userId} postId={post.id} comments={post.Comments} {...props} />
{/* if show more hide show more button and show show less comments button */}
</Fragment>
) : (
<Grid item={true} sm={12} lg={12} style={{ padding: "30px 0px" }}>
<Typography>No Commments Yet</Typography>
</Grid>
)}
<div ref={divRef}></div>
postItemContainer.tsx
import React, { Fragment, useState, useCallback, useRef } from "react";
import Avatar from "#material-ui/core/Avatar";
import Button from "#material-ui/core/Button";
import Grid from "#material-ui/core/Grid";
import Paper from "#material-ui/core/Paper";
import Typography from "#material-ui/core/Typography";
import DeleteOutlineOutlinedIcon from "#material-ui/icons/DeleteOutlineOutlined";
import FavoriteIcon from "#material-ui/icons/Favorite";
import FavoriteBorderIcon from "#material-ui/icons/FavoriteBorder";
import moment from "moment";
import { toast, ToastContainer } from "react-toastify";
import OurLink from "../../../common/OurLink";
import CommentForm from "../comment/CommentForm";
import CommentList from "../commentList/CommentList";
import OurModal from "../../../common/OurModal";
import "react-toastify/dist/ReactToastify.css";
function PostItemContainer(props: any) {
const [openModal, setOpenModal] = useState(false);
const [openForm, setOpenForm] = useState(false);
const [comment_body, setCommentBody] = useState("");
const [gifUrl, setGifUrl] = useState("");
const divRef = React.useRef<any>();
const writeComment = () => {
// this is the same as this.setState({ openForm: !this.state.open })
setOpenForm(!openForm);
};
const commentChange = (comment) => {
setGifUrl("");
setCommentBody(comment);
};
const selectGif = (e) => {
setGifUrl(e.images.downsized_large.url);
setCommentBody("");
// you wont be able to add text comment with a gif, it will look weird :(
};
const handleClickOpen = () => {
setOpenModal(true);
};
const handleCloseModal = () => {
setOpenModal(false);
};
const commentSubmit = (e: any, id: number) => {
e.preventDefault();
const formData = {
comment_body,
id,
gifUrl,
};
props.postComment(formData);
setCommentBody("");
setOpenForm(false);
console.log(divRef);
divRef.current.scrollIntoView({ behavior: "smooth" });
};
const { post, currentUser, getNotifications } = props;
console.log(divRef);
return (
<Fragment>
{getNotifications && <ToastContainer autoClose={1000} position={toast.POSITION.BOTTOM_RIGHT} />}
<Grid item={true} sm={12} md={12} style={{ margin: "20px 0px" }}>
<Paper style={{ padding: "20px" }}>
<Typography variant="h5" align="left">
<OurLink
style={{ fontSize: "16px" }}
to={{
pathname: `/post/${post.id}`,
state: { post },
}}
title={post.title}
/>
</Typography>
<Grid item={true} sm={12} md={12} style={{ padding: "30px 0px" }}>
<Typography align="left">{post.postContent.slice(0, 50)}</Typography>
</Grid>
<Avatar
style={{
display: "inline-block",
margin: "-10px -20px",
padding: "0px 30px 0px 20px",
}}
sizes="small"
src={post.author.gravatar}
/>
<Typography display="inline" variant="subtitle1" align="left">
<OurLink
to={{
pathname: `/profile/${post.author.username}`,
state: { post },
}}
title={post.author.username}
/>
</Typography>
<Typography align="right">Likes: {post.likeCounts}</Typography>
<Grid container={true} spacing={1} style={{ padding: "20px 0px" }}>
<Grid item={true} sm={10} lg={10} md={10} style={{ padding: "0px 0px" }}>
<Typography align="left">
{currentUser && currentUser.user && post.userId === currentUser.user.id ? (
<span style={{ cursor: "pointer" }} onClick={() => props.deletePost(post.id, post.userId)}>
<DeleteOutlineOutlinedIcon style={{ margin: "-5px 0px" }} color="primary" /> <span>Delete</span>
</span>
) : null}
</Typography>
</Grid>
<Grid item={true} sm={2} lg={2} style={{ padding: "0px 15px" }}>
<Typography align="right">
{Object.entries(currentUser).length === 0 ? (
<Fragment>
<span onClick={handleClickOpen}>
<FavoriteBorderIcon style={{ color: "red", cursor: "pointer" }} />
</span>
{openModal ? <OurModal open={openModal} handleClose={handleCloseModal} /> : null}
</Fragment>
) : (
<Fragment>
{post.likedByMe === true ? (
<span style={{ cursor: "pointer" }} onClick={() => props.dislikePost(post.id)}>
<FavoriteIcon style={{ color: "red" }} />
</span>
) : (
<span onClick={() => props.likePost(post.id)}>
<FavoriteBorderIcon style={{ color: "red", cursor: "pointer" }} />
</span>
)}
</Fragment>
)}
</Typography>
</Grid>
</Grid>
<Typography variant="h6" align="left">
{moment(post.createdAt).calendar()}
</Typography>
<Grid item={true} sm={12} lg={12} style={{ paddingTop: "40px" }}>
{Object.entries(currentUser).length === 0 ? (
<Fragment>
<Button onClick={handleClickOpen} variant="outlined" component="span" color="primary">
{"Write A Comment"}
</Button>
{openModal ? <OurModal open={openModal} handleClose={handleCloseModal} /> : null}
</Fragment>
) : (
<Fragment>
<Button onClick={writeComment} variant="outlined" component="span" color="primary">
{openForm ? "Close" : "Write A Comment"}
</Button>
</Fragment>
)}
{openForm ? (
<CommentForm
commentChange={(e: any) => commentChange(e.target.value)}
comment_body={comment_body}
onSubmit={(e) => commentSubmit(e, post.id)}
gifUrl={selectGif}
isGif={gifUrl}
/>
) : null}
{post.Comments.length > 0 ? (
<Fragment>
<Typography style={{ padding: "10px 0px", margin: "20px 0px" }}>Commments</Typography>
<CommentList ref={divRef} user={currentUser} deleteComment={props.deleteComment} userId={post.userId} postId={post.id} comments={post.Comments} {...props} />
{/* if show more hide show more button and show show less comments button */}
</Fragment>
) : (
<Grid item={true} sm={12} lg={12} style={{ padding: "30px 0px" }}>
<Typography>No Commments Yet</Typography>
</Grid>
)}
<div ref={divRef}></div>
</Grid>
</Paper>
</Grid>
</Fragment>
);
}
export default PostItemContainer
CommentList.tsx(just in case) how the comments are bing mapped and iterated
import React, { Fragment, useState } from "react";
import Grid from "#material-ui/core/Grid";
import OurSecondaryButton from "../../../common/OurSecondaryButton";
import CommentListContainer from "../commentListContainer/commentListContainer";
function CommentList(props: any) {
const [showMore, setShowMore] = useState<Number>(2);
const [openModal, setOpenModal] = useState(false);
const [showLessFlag, setShowLessFlag] = useState<Boolean>(false);
const the_comments = props.comments.length;
const inc = showMore as any;
const min = Math.min(2, the_comments - inc);
const showComments = (e) => {
e.preventDefault();
if (inc + 2 && inc <= the_comments) {
setShowMore(inc + 2);
setShowLessFlag(true);
} else {
setShowMore(the_comments);
}
};
const handleClickOpen = () => {
setOpenModal(true);
};
const handleCloseModal = () => {
setOpenModal(false);
};
const showLessComments = (e) => {
e.preventDefault();
setShowMore(2);
setShowLessFlag(false);
};
const isBold = (comment) => {
return comment.userId === props.userId ? 800 : 400;
};
// show comments by recent, and have the latest comment at the bottom, with the previous one just before it.
const filterComments = props.comments
.slice(0)
.sort((a, b) => {
const date1 = new Date(a.createdAt) as any;
const date2 = new Date(b.createdAt) as any;
return date2 - date1;
})
.slice(0, inc)
.reverse();
const showMoreComments = () => {
return filterComments.map((comment, i) => (
<div key={i}>
<CommentListContainer comment={comment} openModal={openModal} handleCloseModal={handleCloseModal} isBold={isBold} handleClickOpen={handleClickOpen} {...props} />
</div>
));
};
return (
<Grid>
<Fragment>
<div style={{ margin: "30px 0px" }}>
{props.comments.length > 2 ? (
<Fragment>
{min !== -1 && min !== -2 ? (
<Fragment>
{min !== 0 ? (
<OurSecondaryButton onClick={(e) => showComments(e)} component="span" color="secondary">
View {min !== -1 && min !== -2 ? min : 0} More Comments
</OurSecondaryButton>
) : (
<OurSecondaryButton onClick={(e) => showLessComments(e)} component="span" color="secondary">
Show Less Comments
</OurSecondaryButton>
)}
</Fragment>
) : (
<OurSecondaryButton onClick={(e) => showLessComments(e)} component="span" color="secondary">
Show Less Comments
</OurSecondaryButton>
)}
</Fragment>
) : null}
</div>
</Fragment>
{showLessFlag === true ? (
// will show most recent comments below
showMoreComments()
) : (
<Fragment>
{/* filter based on first comment */}
{filterComments.map((comment, i) => (
<div key={i}>
<CommentListContainer comment={comment} openModal={openModal} handleCloseModal={handleCloseModal} isBold={isBold} handleClickOpen={handleClickOpen} {...props} />
</div>
))}
</Fragment>
)}
</Grid>
);
}
// prevents un-necesary re renders
export default React.memo(CommentList);

The question seems quite complicated, but i over complicated it.
What i had to do was add this
setTimeout(() => {
divRef.current.scrollIntoView({ behavior: "smooth", block: "center", inline: "nearest" });
}, 1500);
in the commentSubmit method, this will scroll to the recent comment.
const commentSubmit = (e: any, id: number) => {
e.preventDefault();
const formData = {
comment_body,
id,
gifUrl,
};
props.postComment(formData);
setCommentBody("");
setOpenForm(false);
console.log(divRef);
// divRef.current.scrollIntoView({ behavior: "smooth" });
// my attempt to scroll to the lastest comment.
setTimeout(() => {
divRef.current.scrollIntoView({ behavior: "smooth", block: "center", inline: "nearest" });
}, 1500);
}
And make some adjustments to the code, if there are no comments divRef will throw an error upon adding a comment, because it is looking for a comment but there aren't any comments, so we will do this if there are comments less than 1 or 2. In my case im using 2 cause im showing 2 comments initially and i have a filter that shows more comments, and show less.
{post.Comments.length === 0 ? <div ref={divRef}></div> : null}
reference scrollIntoView Scrolls just too far
Rest of the code
{post.Comments.length === 0 ? <div ref={divRef}></div> : null}
{post.Comments.length > 0 ? (
<Fragment>
<Typography style={{ padding: "10px 0px", margin: "20px 0px" }}>Commments</Typography>
<CommentList ref={divRef} user={currentUser} deleteComment={props.deleteComment} userId={post.userId} postId={post.id} comments={post.Comments} {...props} />
{/* if show more hide show more button and show show less comments button */}
</Fragment>
) : (
<Grid item={true} sm={12} lg={12} style={{ padding: "30px 0px" }}>
<Typography>No Commments Yet</Typography>
</Grid>
)}
{post.Comments.length < 2 ? <div ref={divRef}></div> : null}

How to update react state

I have a list of results from my search output. Each result has an onclick function. I want to display each of the results that the user clicks, and for now I can add each result that the user clicks to an array using this function:
let selectedData = []
function addFunc(resultdata){
console.log(resultdata)
selectedData = [...selectedData, resultdata]
console.log(selectedData)
};
I'm new to React, but I know this isn't the right way and I might have to use states or react hooks. The problem is that because I am using Elasticsearch to output the results, my results are in a function, not the main class. Like this:
class Search extends Component {
render() {
return (
<div>
<ReactiveBase
app="datataglist"
credentials="mRgWyoKGQ:f47be2a6-65d0-43b6-8aba-95dbd49eb882"
url="https://scalr.api.appbase.io"
>
<DataSearch
componentId="search"
dataField={[
"maker_tag_name",
"maker_tag_name.autosuggest",
"maker_tag_name.keyword"
]}
fieldWeights={[6, 2, 6]}
fuzziness={1}
highlightField={["maker_tag_name"]}
placeholder="Search Tag Name"
style={{
marginBottom: 20
}}
title="Maker Tag Name"
/>
<Row gutter={16}>
<Col span={8}>
<MultiList
componentId="system"
dataField="system.keyword"
queryFormat="or"
size={100}
sortBy="asc"
style={{
marginBottom: 20
}}
title="System"
/>
</Col>
<Col span={8}>
<MultiList
componentId="grouping"
dataField="grouping.keyword"
size={100}
style={{
marginBottom: 20
}}
title="Grouping"
/>
</Col>
<Col span={8}>
<MultiList
componentId="unit"
dataField="units.keyword"
size={100}
style={{
marginBottom: 20
}}
title="Unit"
/>
</Col>
</Row>
<SelectedFilters />
<ReactiveList
componentId="results"
dataField="_score"
pagination={true}
react={{
and: ["system", "grouping", "unit", "search"]
}}
size={10}
noResults="No results were found..."
renderItem={RenderItem}
/>
</ReactiveBase>
<div>
</div>
</div>
);
}
}
function getNestedValue(obj, path) {
const keys = path.split(".");
const currentObject = obj;
const nestedValue = keys.reduce((value, key) => {
if (value) {
return value[key];
}
return "";
}, currentObject);
if (typeof nestedValue === "object") {
return JSON.stringify(nestedValue);
}
return nestedValue;
}
function RenderItem(res, triggerClickAnalytics) {
let { unit, title, system, score, proposed, id } = {
title: "maker_tag_name",
proposed: "proposed_standard_format",
unit: "units",
system: "system",
score: "_score",
id: "_id"
};
title = getNestedValue(res, title);
system = getNestedValue(res, system);
unit = getNestedValue(res, unit);
score = getNestedValue(res, score);
proposed = getNestedValue(res, proposed);
id = getNestedValue(res, id);
const resultdata = {id, title, system, unit, score, proposed}
return (
<Row
onClick={triggerClickAnalytics}
type="flex"
gutter={16}
key={res._id}
style={{ margin: "20px auto", borderBottom: "1px solid #ededed" }}
>
<Col style={{ width: "360px" }}>
<h3
style={{ fontWeight: "600" }}
dangerouslySetInnerHTML={{
__html: title || "Choose a valid Title Field"
}}
/>
</Col>
<div style={{ padding: "20px" }} />
<Col>
<p
style={{ fontSize: "1em", width: "300px" }}
dangerouslySetInnerHTML={{
__html: system || "Choose a valid Description Field"
}}
/>
</Col>
<div style={{ padding: "10px" }} />
<Col>
<p
style={{ fontSize: "1em" }}
dangerouslySetInnerHTML={{
__html: unit || "-"
}}
/>
</Col>
<div style={{ padding: "10px" }} />
<Col style={{ minWidth: "120px" }}>
<p
style={{ fontSize: "1em", width: "300px"}}
dangerouslySetInnerHTML={{
__html: proposed || "Choose a valid Description Field"
}}
/>
</Col>
<div style={{ padding: "10px" }} />
<Col>
<p
style={{ fontSize: "1em"}}
dangerouslySetInnerHTML={{
__html: Math.round(score) || "Choose a valid Description Field"
}}
/>
</Col>
<Col>
<Button
shape="circle"
icon={<CheckOutlined />}
style={{ marginRight: "5px" }}
onClick={()=> {addFunc(resultdata)}}
/>
</Col>
</Row>
);
}
Basically, my ReactiveList component is what shows the results. This calls the RenderItem function, which is what displays the data on the screen. In my function, I have a list called resultdata, which contains all the data I need when each result is clicked on. This works, but I need it to display on the screen.
I can't use state, because I have a function. And I can't use hooks because it isn't the main function. Am I doing something wrong? Is there any other alternative to this?
Even if you can't provide a complete answer, I would appreciate any tips on which direction I should look towards.

state is async so it wont update like this:
function addFunc(resultdata){
console.log(resultdata)
selectedData = [...selectedData, resultdata]
console.log(selectedData)
};
and you are using a class so you can't useHooks but setState takes a callback as second argument
function addFunc(resultdata){
console.log(resultdata)
this.setState({selectedData: [...selectedData, resultdata]}, () => console.log(selectedData))
};
so if you continue using a Class approach this will allow you to use setState and utilize the callback in it
there is a callback available too in hooks but it doesn't work quite the same

Place addFunc within the parent component and make your RenderItem function a React Functional component by exporting it. Then provide the addFunc as a function prop from parent component to RenderItem component. That way you can call the function within onClick event. Any of the parent states can be updated from the addFunc. You can supply necessary arguments to the function call as well.

ReactJS In a user profile display only fields that have a value

Objective
Displaying only the fields that are filled in.
Background
In my application people will first fill out the application which has fields like "early reg fee, early reg date, regular reg fee, regular reg date" and so after they fill out all the information and click "view profile" they will see all the fields whether it's filled out or not.
If the value of one of the fields is null or undefined then it would not show up in the profile.
I was trying to do this and I started of by creating a state in the constructor "this.state {value: ''}"
class CompetitionProfileView extends React.Component {
constructor(props) {
super(props);
this.state {value: ''}
this.getContactCard = this.getContactCard.bind(this);
}
getCompetitionValue(path) {
const value = _.get(this.props.competition, path);
return value ? value : '';
}
getCompetitionDateValue(path) {
const value = _.get(this.props.competition, path);
return value ? value.toDateString() : '';
}
getCompetitionTimeValue(path) {
const value = _.get(this.props.competition, path);
return value ? `${
value.getHours() - 12
}:${value.getMinutes()}` : '';
}
getContactCard(num) {
return
this.getCompetitionValue(`Information.contactFirstName${num}`) ?
<Card key={num} style={{backgroundColor: '#f9f9f9', width: '32%'}} zDepth={2}>
<CardTitle title={`${this.getCompetitionValue(`Information.contactFirstName${num}`)} ${this.getCompetitionValue(`Information.contactFirstName${num}`)}`} subtitle={`${this.getCompetitionValue('Information.contactPosition1')}`} />
<Divider/>
<CardText>
<p style={{display: 'flex', justifyContent: 'center'}}><Phone/>{`${this.getCompetitionValue(`Information.contactFirstName${num}`)}`}</p>
<p style={{display: 'flex', justifyContent: 'center'}}><Email/>{`${this.getCompetitionValue(`Information.contactFirstName${num}`)}`}</p>
</CardText>
</Card>
:
'';
}
render(actions) {
return (
<div>
<div className="profileheader" style={{display: 'flex', flexDirection: 'column'}}>
<Paper className='banner-image' style={{backgroundImage: `url(${this.getCompetitionValue('Resources.boardPicture.url')})`,backgroundSize: 'cover',width: '100%', height: '200px', backgroundPositionY: '20%'}} zDepth={3}>
{/* <br style={{lineHeight: '15'}}/> */}
</Paper>
<Paper className='text-main' style={{textAlign: 'center'}}>
<label>{this.getCompetitionValue('Information.name')}</label>
</Paper>
<Paper className='logo-image' style={{backgroundImage: `url(${this.getCompetitionValue('Resources.competitionLogo.url')})`, backgroundSize: 'cover', width: '100px', height: '100px', marginTop: '-110px', marginLeft: '3%', paddingbottom: '20px'}} zDepth={3}/>
</div>
<hr/>
<div style={{display: 'flex', justifyContent: 'space-between'}}>
<Card style={{backgroundColor: '#f9f9f9', width: '49%'}} zDepth={2}>
<RaisedButton style={{display: 'flex', justifyContent: 'center'}} primary={true} label="Application Packet" onClick={() => window.open(this.getCompetitionValue('Resources.applicationPacket.url'), '_blank')}/>
</Card>
<Card style={{backgroundColor: '#f9f9f9', width: '49%'}} zDepth={2}>
<RaisedButton style={{display: 'flex', justifyContent: 'center'}} primary={true} label="Audition Video Info" onClick={() => window.open(this.getCompetitionValue('Resources.auditionVideoInfo.url'), '_blank')}/>
</Card>
</div>
<br/>
<div className='mainbody' style={{display: 'flex', flexDirection: 'row', justifyContent: 'space-between'}}>
<br/>
<div className='rightbody' style={{display: 'flex', flexDirection: 'column', width: '60%', flexWrap: 'wrap'}}>
<Card style={{backgroundColor: '#F0EFEF'}} zDepth={2}>
<CardHeader title="About Us" />
<Divider/>
<CardText>{`${this.getCompetitionValue('Information.compBlurb')}`}</CardText>
</Card>
<br/>
<Card style={{backgroundColor: '#F0EFEF'}} zDepth={2}>
<CardHeader title="Application Information" />
<Divider/>
<CardText>
<p><b>Early Reg:</b>{` ${this.getCompetitionDateValue('Information.dueDateEarly')}`}</p>
<p><b>Early Reg Fee:</b>{` ${this.getCompetitionValue('Information.earlyDues')}`}</p>
<p><b>Regular Reg:</b>{` ${this.getCompetitionDateValue('Information.dueDateRegular')}`}</p>
<p><b>Regular Reg Fee:</b>{` ${this.getCompetitionValue('Information.regularDues')}`}</p>
<p><b>Late Reg:</b>{` ${this.getCompetitionDateValue('Information.dueDateLate')}`}</p>
<p><b>Late Reg Fee:</b>{` ${this.getCompetitionValue('Information.lateDues')}`}</p>
<p><b>Applications Due At:</b>{` ${this.getCompetitionTimeValue('Information.dueTime')}`}</p>
<p><b>Time Zone:</b>{` ${this.getCompetitionValue('Information.timeZone')}`}</p>
<p><b>Penalties:</b>{` ${this.getCompetitionValue('Information.extraFees')}`}</p>
<p><b>Hear Back Date:</b>{` ${this.getCompetitionDateValue('Information.hearbackDate')}`}</p>
<p><b>Payment Method:</b>{` ${this.getCompetitionValue('Information.paymentMethods')}`}</p>
<br/>
</CardText>
</Card>
</div>
</div>
<br/>
<div className="contactinfo" style={{display: 'flex', justifyContent: 'space-around'}}>
{[1,2,3].map((num) => this.getContactCard(num))}
</div>
<br/>
{this.props.competition.Board.length > 0 &&
<Card style={{backgroundColor: '#F0EFEF'}} zDepth={2}>
<Table >
<TableHeader adjustForCheckbox={false} displaySelectAll={false}>
<TableRow>
{ Object.keys(this.props.competition.Board[0]).map((key) => <TableHeaderColumn key={key}>{key}</TableHeaderColumn>) }
</TableRow>
</TableHeader>
<TableBody displayRowCheckbox={false}>
{this.props.competition.Board.map((row, i) => (
<TableRow key={i}>
{ Object.keys(row).map((column) => <TableRowColumn key={column}>{row[column].name ? row[column].name : row[column]}</TableRowColumn>) }
</TableRow>
))
}
</TableBody>
</Table>
</Card>
}
</div>
);
}
}
const mapStateToProps = (state) => {
return {
messages: state.messages
};
};
export default connect(mapStateToProps)(CompetitionProfileView);

You can use if statements in your render() function, like so:
render() {
if (this.props.thing1) {
return <h1>Thing 1</h1>
} else {
return (
<div className="warning">
<h2>Thing 2</h2>
</div>
)
}
}
You can even use functions in the render() function like this:
renderASmallPart() {
if (this.props.thing1) {
return <h1>Thing 1</h1>
} else {
return (
<div className="warning">
<h2>Thing 2</h2>
</div>
)
}
}
render() {
return (
<div>
<h1>My App</h1>
<h2>Here's a thing:</h2>
{this.renderASmallPart()}
</div>
)
}
You can use this to break up your large render() function into smaller functions that check what the value of their field is and only render something when the field has a non-empty value

You need to look into Conditional Rendering and only render that element when there is a value.
https://facebook.github.io/react/docs/conditional-rendering.html
https://atticuswhite.com/blog/render-if-conditionally-render-react-components/
http://devnacho.com/2016/02/15/different-ways-to-add-if-else-statements-in-JSX/
https://kylewbanks.com/blog/how-to-conditionally-render-a-component-in-react-native