Reputation:
I'm learning React and have done a fair bit of research on this. I've quickly discovered that the map()
function is what I think I should be using for looping through an array.
But, my problem is all the examples in the React documentation and in the SO questions I've viewed use <ul>
and <li>
HTML elements to handle the output.
I'm not sure that my use case is "correct" as far as React structure is concerned, but, I want to output a <div>
with some child elements each time I loop through.
Here is my static code so far:
const Comment = () => {
return (
<div className="commenter">
<div className="commenter-inner">
<div className="commenter-left">
<img src={chachi}/>
<p className="commenter-name">Scott Baio</p>
</div>
<div className="commenter-comment">
<p>Ehhhh!! Joanie loves Chachi!!!</p>
</div>
</div>
</div>
)
}
This works, but now if I have additional comments I want to be able to serve up the same block of code again but with the new commenters name, image, comment content etc.
So I've now made an array to house my multiple commenters, and things aren't really working anymore.
import React, { Component } from 'react'
import fonzie from "./img/the-fonz.jpg";
import chachi from "./img/chachi.jpg";
const Comments = [
{
id: 1,
name: 'Hello World',
photo: fonzie,
comment: 'Welcome to learning React!'
},
{
id: 2,
name: 'Hello World',
photo: chachi,
comment: 'Welcome to learning React!'
}
];
const commentEngine = props.Comments.map((comment) =>
<div className="commenter" key={comment.id}>
<div className="commenter-inner">
<div className="commenter-left">
<img src={comment.photo}/>
<p className="commenter-name">{comment.name}</p>
</div>
<div className="commenter-comment">
<p>{comment.comment}</p>
</div>
</div>
</div>
);
class Comments extends Component {
render() {
return (
<div className="comments-section col-md-10 offset-md-1 col-sm-12">
<h4>Comments</h4>
<commentEngine />
</div>
);
}
}
export default Comments
At this point I'm unsure how to verify if my loop is working in the first place and how to get the output properly displaying in my app.
Any help is greatly appreciated, as is insight into whether or not this is well structured or should be separate components.
Thanks!
Upvotes: 0
Views: 273
Reputation: 2609
const commentEngine = (comments) => {
return comments.map((comment)=>{
return (
<div className="commenter" key={comment.id}>
<div className="commenter-inner">
<div className="commenter-left">
<img src={comment.photo}/>
<p className="commenter-name">{comment.name}</p>
</div>
<div className="commenter-comment">
<p>{comment.comment}</p>
</div>
</div>
</div>
)})
class Comments extends Component {
render() {
return (
<div className="comments-section col-md-10 offset-md-1 col-sm-12">
<h4>Comments</h4>
{commentEngine(props.Comment)}
</div>
);
}
}
Now when you render Comments you need to pass the Comment props.
<Comments Comment={Comments}/>
Upvotes: 1
Reputation: 1145
import React, { Component } from 'react'
import fonzie from "./img/the-fonz.jpg";
import chachi from "./img/chachi.jpg";
const Comments = [
{
id: 1,
name: 'Hello World',
photo: fonzie,
comment: 'Welcome to learning React!'
},
{
id: 2,
name: 'Hello World',
photo: chachi,
comment: 'Welcome to learning React!'
}
];
const Comment = props =>
const {comment} = props;
<div className="commenter" key={comment.id}>
<div className="commenter-inner">
<div className="commenter-left">
<img src={comment.photo}/>
<p className="commenter-name">{comment.name}</p>
</div>
<div className="commenter-comment">
<p>{comment.comment}</p>
</div>
</div>
</div>
);
class Comments extends Component {
render() {
return (
<div className="comments-section col-md-10 offset-md-1 col-sm-12">
<h4>Comments</h4>
{Comments.map((comment,index) => <Comment key={'[CUSTOM_KEY]'} props={comment}> )}
</div>
);
}
}
export default Comments
index
parameter in Array.map
<Comment comment={comment}>
and you can use it with Array.map
How to make functional component
Upvotes: -1
Reputation: 13642
It sounds like you want to re-use the Comment
component with data passed by Comments
. In React, this is done via props.
So, you'll want to pass the images's src
, the name, and the description:
const comments = [
{
id: 1,
name: "Hello World",
photo: fonzie,
comment: "Welcome to learning React!",
},
{
id: 2,
name: "Hello World",
photo: chachi,
comment: "Welcome to learning React!",
},
];
class Comments extends Component {
render() {
return (
<div className="comments-section col-md-10 offset-md-1 col-sm-12">
<h4>Comments</h4>
{comments.map((comment) => {
return (
<Comment
key={comment.id} // https://reactjs.org/docs/lists-and-keys.html
name={comment.name}
imgSrc={comment.photo}
comment={comment.comment}
/>
);
})}
</div>
);
}
}
Notice that I've renamed the constant array Comments
to comments
so that the name doesn't clash with the Comments
component.
Then in the Comment
component, you can access these props via the argument passed to the function component:
const Comment = (props) => {
return (
<div className="commenter">
<div className="commenter-inner">
<div className="commenter-left">
<img src={props.imgSrc} />
<p className="commenter-name">{props.name}</p>
</div>
<div className="commenter-comment">
<p>{props.comment}</p>
</div>
</div>
</div>
);
};
Additionally, we can make the code a bit less verbose by leveraging object destructuring:
class Comments extends Component {
render() {
return (
<div className="comments-section col-md-10 offset-md-1 col-sm-12">
<h4>Comments</h4>
{comments.map(({ id, name, photo, comment }) => {
return (
<Comment key={id} name={name} imgSrc={photo} comment={comment} />
);
})}
</div>
);
}
}
// ...
const Comment = ({ imgSrc, name, comment }) => {
return (
<div className="commenter">
<div className="commenter-inner">
<div className="commenter-left">
<img src={imgSrc} />
<p className="commenter-name">{name}</p>
</div>
<div className="commenter-comment">
<p>{comment}</p>
</div>
</div>
</div>
);
};
Upvotes: 1