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Combine two React files into one

I have two files that return html fragments. They are identical except for the image. The fact is that the server has different paths to the playlist image and the genre image.
props.items.images[0].url
and
props.items.icons[0].url
because of this, I had to distribute this code to two different files. How could I combine them into one?
const Playlist = props => {
const playListClick = e => {
props.onClick(e.target.title);
}
return (
<section id={props.selectedValue} className="column column__hidden" onClick={playListClick}>
<a className="link__decoration link__track hover__track link__one" href="#">
<div>
{props.items.map((item, idx) =>
<div className="container" key={idx + 1} title={item.id} >
<div className="content__track" title={item.id}>
<img className="img__tarck" title={item.id} src={item.images[0].url}/>
<div className="name" title={item.id}>{item.name}</div>
</div>
</div>)}
</div>
</a>
</section>
);
}
const Genre = props => {
const genreClick = e => {
props.onClick(e.target.title);
}
return (
<section id={props.selectedValue} className="column column__hidden" onClick={genreClick}>
<a className="link__decoration link__track hover__track link__one" href="#">
<div>
{props.items.map((item, idx) =>
<div className="container" key={idx + 1} title={item.id}>
<div className="content__track" title={item.id}>
<img className="img__tarck" title={item.id} src={item.icons[0].url}/>
<div className="name" title={item.id}>{item.name}</div>
</div>
</div>)}
</div>
</a>
</section>
);

You can use a Conditional (ternary) Operator to look if icons exists and if not fallback to using the image. Further assistance is hard due to not knowing the surrounding circumstances.
<img className="img__tarck" title={item.id} src={item.icons ? item.icons[0].url : item.images[0].url}/>

hide a div in react when there is no anchor tag in it

I have a react code (just a snippet, its not a complete code) as shown below which shows the list of programs on the webpage. Line A in the react code below renders all list of program on the webpage.
react code:
const renderPrograms = () => {
return programs.map((program, index)=>{
return (
<a href={program.url} key={index}>
<div className="program" >
<div class="hello-world">{program.name}</div>
</div >
</a>
)
})
}
return(
<div class="parent-div">
<div className ="pqr-xyz">
<h5>Hello World</h5>
</div>
<div className ="abc-def">
<h5>Programs</h5>
{programs && renderPrograms()} {/*Line A*/}
</div>
</div>
)
The above react code renders the following html code at runtime:
<div class="parent-div">
<div className ="pqr-xyz">
<h5>Hello World</h5>
</div>
<div class="abc-def">
<h5>Programs</h5>
<a href="https://www.google.com/">
<div class="program">
<div class="hello-world">TYUV</div>
</div>
</a>
<a href="https://www.twitter.com/">
<div class="program">
<div class="hello-world">SGHS</div>
</div>
</a>
</div>
</div>
Problem Statement:
When Line A does not render anything, my div (<div className ="abc-def">) will look like this at run time:
<div class="abc-def">
<h5>Programs</h5>
</div>
I am wondering what changes I need to make in my react code above so that when Line A doesn't render anything then <div class="abc-def"><h5>Programs</h5></div> should not display on the webpage.

They should be part of the condition:
return(
programs.length > 0 && <div className ="abc-def">
<h5>Programs</h5>
{renderPrograms()}
</div>
)
I changed the condition to check for length, otherwise you'll get a 0 instead of nothing, when empty

Try change this lines:
<div className ="abc-def">
<h5>Programs</h5>
{programs && renderPrograms()} {/*Line A*/}
</div>
into this:
{ programs && (
<div className ="abc-def">
<h5>Programs</h5>
{renderPrograms()} {/*Line A*/}
</div>
) }
Now without programs nothing is displayed.

You can try adding a className like this:
<div className={`abc-def ${programs.length ? "hidden" : ""}`}
Or from the parent componet, you can choose to not render this component with <div>

Instead of trying to hide it using CSS, you also can choose to not render it at all by returning nothing from your function
const RenderPrograms = ({ programs = [] }) => {
if (!programs.length) {
return []
}
return (
<div className="abc-def">
<h5>Programs</h5>
{programs.map((program, index) =>
<a href={program.url} key={index}>
<div className="program">
<div>{program.name}</div>
</div>
</a>
)}
</div>
)
}
ReactDOM.render(
<RenderPrograms />,
document.getElementById('react')
)
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.8.4/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.8.4/umd/react-dom.production.min.js"></script>
<div id="react"></div>

You can try putting your class in a template string and using a ternary operator to display a certain class when some state value is true.
<div className={`${stateValue ? "name-of-class-with-hide" : "abc-def"}`}>

Here is a complete solution. All you need to do is move the <h5>Programs</h5> inside the condition and modify the condition slightly as shown in following snippet.
<div className ="abc-def">
{
programs.length > 0 && (
<div>
<h5>Programs</h5>
<RenderPrograms programs = {programs}/>
</div>
)
}
</div>
Note that I have modified the RenderPrograms function as well to accept arguments.
Following is a full snippet.
function RenderPrograms(props) {
return props.programs.map((program, index)=>{
return (
<a href={program.url} key={index}>
<div className="program" >
<div className="hello-world">{program.name}</div>
</div >
</a>
)
});
}
function MyApp() {
const programs=[
{name:'program 1', url: 'https://url1.com'},
{name:'program 2', url: 'url2'},
{name:'program 3', url: 'url3'},
];
const programs1 = []; // empty program list
return(
<div class="parent-div">
<h1>When programs list is not empty</h1>
{/*Above line is just for explanation -- you may remove it*/}
<div className ="pqr-xyz">
<h5>Hello World</h5>
</div>
<div className ="abc-def">
{
programs.length > 0 && (
<div>
<h5>Programs</h5>
<RenderPrograms programs = {programs}/>
</div>
)
}
</div>
{/*Below code is just for explanation -- you may remove it*/}
<hr />
<h1>When programs list is empty</h1>
<div className ="pqr-xyz">
<h5>Hello World</h5>
</div>
<div className ="abc-def">
{
programs1.length > 0 && (
<div>
<h5>Programs</h5>
<RenderPrograms programs = {programs1}/>
</div>
)
}
</div>
</div>
)
}
ReactDOM.render(
<MyApp />,
document.getElementById('app')
)
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<div id="app"></div>

You need to move rendering of programs into RenderPrograms component. Make RenderPrograms component purelu functional and pass data to it via props (Instead of using function).
const RenderPrograms = ({ programs }) => {
let disp = programs.map((program, index) => {
return (
<a href={program.url} key={index}>
<div className="program">
<div class="hello-world">{program.name}</div>
</div>
</a>
);
});
return disp || <span />;
};
then use RenderPrograms to render programs in main component (One with logis for loading programs).
// let programs = [
// {
// url: "test1.com",
// name: "test1"
// },
// {
// url: "test2.com",
// name: "test2"
// }
// ];
let programs = [];
return (
<div className="App">
<div class="parent-div">
<div className="pqr-xyz">
<h5>Hello World</h5>
</div>
<div className="abc-def">
<h5>Programs</h5>
<RenderPrograms programs={programs} />
{/* {programs && renderPrograms()} Line A */}
</div>
</div>
</div>
);
You can play around with this sandbox

Couldn't get rid of react warning of unique key in map

What's wrong with my below code? I had key={obj._id} and I expect I will not see the warning but I'm still getting it.
Warning: Each child in an array or iterator should have a unique "key"
prop. Check the render method..
renderListItems(items){
return(
<div>
{map(items, obj =>
<div key={obj._id} className="panel-body panel-row">
<div className="row">
<div className="col-md-12">
<h2 className="title">{obj.display_name}</h2>
<p className="edited">Last edited on {moment(obj.updated_at).format('DD MMM YYYY')}</p>
<div className="actions_wrap">
<Link to={`/mall-promospace/edit/${obj._id}`}>Edit</Link>
<a onClick={()=> this.setState({openConfirmationModal:true, selectedItemId: obj._id, selectedItemName: obj.display_name})}>Delete</a>
</div>
</div>
</div>
</div>
)}
</div>
)
}

I think you are coding some things wrong. You should apply the function "map" over an array.
Try this:
renderListItems(items){
return(
<div>
{items.map(obj =>
<div key={obj._id} className="panel-body panel-row">
<div className="row">
<div className="col-md-12">
<h2 className="title">{obj.display_name}</h2>
<p className="edited">Last edited on {moment(obj.updated_at).format('DD MMM YYYY')}</p>
<div className="actions_wrap">
<Link to={`/mall-promospace/edit/${obj._id}`}>Edit</Link>
<a onClick={()=> this.setState({openConfirmationModal:true, selectedItemId: obj._id, selectedItemName: obj.display_name})}>Delete</a>
</div>
</div>
</div>
</div>
)}
</div>
)
}

items.map((obj, i) => <div key={i}></div>)

Using odd/even switch for classNames

I want each this.state.title to align according to a different classname.
I tried using css flex boxes/nth-of-type/nth-child, but it did not play nicely with React.
I'm using this.state to get my objects.
My unsuccessful attempt
render: function () {
let className
var newVar = !someVar;
switch(someVar) {
case odd:
className= "post-1 line";
break;
case even:
className = "post-2 right-align line";
break;
}
return (
<article class={I WANT THIS TO FILL FROM SWITCH}>
<div class="s-12 l-6 post-image">
<a href="post-1.html">
<img src="/post1.jpg">
</a>
</div>
<div class="s-12 l-5 post-text">
<a href="#">
<h2>{this.state.title}</h2>
</a>
<p>Testing
</p>
</div>
<div class="s-12 l-1 post-date">
<p class="date">28</p>
<p class="month">feb</p>
</div>
</article>
);
}
});

react rewrite class attribute as className,see react for more details.
render: function () {
let className = ['post-2 right-align line', 'post-1 line'][someVar % 2];
return (
<article className={className}>
<div className="s-12 l-6 post-image">
<a href="post-1.html">
<img src="/post1.jpg"/>
</a>
</div>
<div className="s-12 l-5 post-text">
<a href="#">
<h2>{this.state.title}</h2>
</a>
<p>Testing
</p>
</div>
<div className="s-12 l-1 post-date">
<p className="date">28</p>
<p className="month">feb</p>
</div>
</article>
);
}

The 'someVar' is local variable ? You can try write it in state, Via this.setState mutate it for your need.

here is the whole example like this:
class Item extends Component {
render() {
let {index, title}=this.props;
let className = ['post-2 right-align line', 'post-1 line'][index % 2];
return <li key={index} id={index} className={className}>{title}</li>
}
}
class TodoList extends Component {
render() {
let i = 0;
let itemFactory = (props = {}) => {
return <Item key={i} index={i++} {...props}/>
};
return (<ul>
{this.props.items.map((item) => itemFactory({title: item}))}
</ul>);
}
}
ReactDOM.render(
<TodoList items={['first', 'second', 'last']}/>,
document.getElementById('container')
);

Sort array onClick and render the array in React

I have an array full of objects that I fetched and I am trying to sort the array onClick of an arrow in React. I have a sort function that works perfect in javascript but I am new to React and can't figure out how to implement the function and render the list again.
I am getting errors messages of all sorts depending on what I try. Anything from cannot sort undefined to 'expecting onclick to be a function instead of an object like in this case.
var LeaderBoard = React.createClass({
sortDescending: function(property) {
return function (a,b) {
return (a[property] > b[property]) ? -1 : (a[property] < b[property]) ? 1 : 0;
}
},
getInitialState: function() {
return {
data: loading
};
},
componentWillMount: function() {
fetch('https://fcctop100.herokuapp.com/api/fccusers/top/recent', {
method: 'get'
}).then(response => response.json()).then(data => {
this.setState({
data: data,
});
}).catch(function(error) {
console.log("error is ", error);
});
},
render: function() {
var information = [];
for (var j=0; j<13; j++) {
information.push(
<div className="row" key={this.state.data.username}>
<div className="col-md-1 col-xs-1">
<h4>{j+1}</h4>
</div>
<div className="col-md-4 col-xs-4">
<h4>{this.state.data[j].username}</h4>
</div>
<div className="col-md-4 col-xs-4">
<h4>{this.state.data[j].recent}</h4>
</div>
<div className="col-md-3 col-xs-3">
<h4>{this.state.data[j].alltime}</h4>
</div>
</div>
);
}
return (
<div>
<div id="Title" className="row">
<h1>freeCodeCamp Leaderboard</h1>
</div>
<div className="row">
<div className="col-md-1 col-xs-1">
<h4>#</h4>
</div>
<div className="col-md-3 col-xs-3">
<h4>Camper Name
</h4>
</div>
<div className="col-md-5 col-xs-5">
<h4>Points in past 30 days
<img className="arrow" src="https://cdn4.iconfinder.com/data/icons/ionicons/512/icon-arrow-up-b-128.png" />
<img className="arrow" onClick = {this.state.data.sort(this.sortDescending("recent"))}
src="https://cdn4.iconfinder.com/data/icons/ionicons/512/icon-arrow-down-b-128.png" />
</h4>
</div>
<div className="col-md-3 col-xs-3">
<h4>All time points</h4>
</div>
</div>
<div>{information}</div>
</div>
);
}
});

You are setting onClick to tbe result of a function, not tbe function itself.
Replace
`<img className="arrow" onClick={this.state.data.sort(this.sortDescending("recent"))} src="https://cdn4.iconfinder.com/data/icons/ionicons/512/icon-arrow-down-b-128.png" />`
With
<img className="arrow" onClick = {() => this.state.data.sort(this.sortDescending("recent"))} src="https://cdn4.iconfinder.com/data/icons/ionicons/512/icon-arrow-down-b-128.png" />
React onClick events cannot be anything but a function, for future reference. (Also, JS refers to Arrays sometimes as Objects, which explains the error you're getting)