React 'Hello World' not loading - reactjs

I'm following a guide in a book about creating React apps. This is the very first example in the book and I copied it exactly as it was, but the page won't render.
<!DOCTYPE HTML>
<html>
<head>
<meta charset="UTF-8" />
<title> Pro MEAN Stack </title>
<script src=
"https://cdnjs.cloudflare.com/ajax/libs/react/15.2.1/react.js">
</script>
<script src=
"https://cdjns.cloudflare.com/ajax/libs/react/15.2.1/react-dom.js">
</script>
<script src=
"https://cdjns.cloudflare.com/ajax/libs/babel-core/5.8.23/browser.min.js">
</script>
</head>
<body>
<div id="contents"></div> <!-- this is where the component will appear -->
<script type="text/babel">
var contentNode = document.getElementById('content');
var component = <h1> Hello World </h1>; // A simple JSX component
ReactDOM.render(component, contentNode); // Render the conponent
</script>
</body>
</html>
Here's what the console says,
react-dom.js Failed to load resource: net::ERR_NAME_NOT_RESOLVED
browser.min.js Failed to load resource: net::ERR_NAME_NOT_RESOLVED
I'm not sure what to do at this point. I've never worked with React before

You should update your cdn links to valid ones, use these:
<script src="https://unpkg.com/react#15/dist/react.js"></script>
<script src="https://unpkg.com/react-dom#15/dist/react-dom.js"></script>
contents => content
The preferred way to use react is with some kind of module bundler like webpack. If webpack seems like a hustle you could use create-react-app to have a full react application up and running in no time. it's great.

Fix the links to cdnjs, you misspell it. Also you are creating a div with id "contents", then you select an element with id "content".

The following example works:
<!DOCTYPE HTML>
<html>
<head>
<meta charset="UTF-8" />
<title>ReactJS Hello World</title>
<script src="https://unpkg.com/react#15/dist/react.js"></script>
<script src="https://unpkg.com/react-dom#15/dist/react-dom.js"></script>
<script src=
"https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.25.0/babel.min.js">
</script>
</head>
<body>
<div id="content"></div>
<script type="text/babel">
var contentNode = document.getElementById('content');
var component = <h1> Hello World </h1>; // A simple JSX component
ReactDOM.render(component, contentNode); // Render the conponent
</script>
</body>
</html>
References
Getting started with React the easy way | CodeUtopia
React without build steps - Babel Standalone
Actualize | Anyone Can Learn To Code

Related

Simple React Hello World Implementation

I have been attempting to run a simple hello world react application. I am not using any tools. I have created an index.html and index.js in the same directory. Within my index.js, if I turn the elements variable into a string, it works, but not how I expected it to work. It passes a string in and that string is displayed exactly as typed
<h1>Hello, world</h1>
I want to pass the html into the render method but I keep getting the following error:
Uncaught SyntaxError: Unexpected token <
See code below:
'use strict'
const element = <h1>Hello, world</h1>;
ReactDOM.render(element, document.getElementById('app'));
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>Hello World</title>
</head>
<body>
<div id="app"></div>
<script crossorigin src="https://unpkg.com/react#16/umd/react.production.min.js"></script>
<script crossorigin src="https://unpkg.com/react-dom#16/umd/react-dom.production.min.js"></script>
<script src="index.js"></script>
</body>
</html>
The tutorial that I am following is:
https://reactjs.org/docs/rendering-elements.html
Without using babel, we can't use jsx. See the solution below and note the React.createElement function instead of passing html directly into the ReactDOM.render function.
Solution:
'use strict'
ReactDOM.render(React.createElement('h1', null, 'Hello, world'), document.getElementById('app'));
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>Hello World</title>
</head>
<body>
<div id="app"></div>
<script crossorigin src="https://unpkg.com/react#16/umd/react.production.min.js"></script>
<script crossorigin src="https://unpkg.com/react-dom#16/umd/react-dom.production.min.js"></script>
<script src="index.js"></script>
</body>
</html>
I don't think it's possible to use JSX syntax without a bundler/Babel.
You have to use React.createElement('h1', null, 'Hello, world').
Source: https://medium.com/#clmyles/react-without-npm-babel-or-webpack-1e9a6049714
Edit:
If you plan to use Babel, #Chris answer in his comment (import React ...) is correct. React then needs to be in scope to use JSX.

browser does not displays/executes ReactJS code

I have written a simple hello world code in ReactJS, but when I run the code, the browser displays nothing. There is not any error displayed on console. Please tell what can be the problem. I am using WebStrom compiler, Chrome as browser and Windows 8.1 is the OS.
index.html
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>First React App</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.13.3/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.13.3/JSXTransformer.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<script src="script.jsx" type="text/babel"></script>
</head>
<body>
<div id="content"></div>
</body>
</html>
script.js
var MyComponent = React.createClass({
render :function() {
return(
<h2>Heading 2</h2>
);
}
});
React.render(
<MyComponent/>, document.getElementById('content')
);
project directory
browser display
It could be that your script.js should be script.jsx?
It's a babel issue you're running into. Try replacing JSXTransformer with the official babel package:
<script src="https://unpkg.com/babel-standalone#6/babel.min.js"></script>

why I get blank page when I browse to localhost:3000?

trying this react example after I start the server at port 3000 I get a blank page. Here is the code:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title></title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/6.1.19/browser.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.5.4/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.5.4/react-dom.js"></script>
</head>
<body>
<div id="app"></div>
<script type="text/babel">
ReactDOM.render(
<h1>Hello React</h1>,
document.getElementById('app')
);
</script>
</body>
</html>
So why I get blank page ?
I see there is an error in the console but I dont know if this is the problem or not. I am on windows 10
it seems last version of babel has a problem I switched to 5.8.23 and I get "Hello Ract" normally !!

Basic element rendering in ReactJS is not working

I am learning ReactJS. I visited this in order to have some basic lessons. After going through first lesson, I could write following code:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>Hello world with date time in ReactJS</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.2.1/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.2.1/react-dom.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.34/browser.min.js"></script>
</head>
<body>
<div id="root"></div>
<script type="text/jsx">
const element = <h1>Hello, world</h1>;
ReactDOM.render(
element,
document.getElementById('root')
);
</script>
</body>
</html>
But to my surprise, it is working here but not on my computer or at my fiddle here. Can you please show me why my code is not working? Thanks.
Change text/jsx to text/babel . It works.
The problem is that you don't have JSX processing enabled.
If you're using jsFiddle you can move your JS code to JavaScript edit section and click on settings button in top-right corner of this section and then select Babel + JSX from language select.

React starter kit Hello World program error

I am trying to make an "Hello World" program as suggest on react tutorial.
But I created helloworld.js under src and helloworld.html in root. When I try to run my helloworld.html nothing happens (at all). And when I try to run helloworld.js error described below comes.
Is it some issue with babel?
Your first question, why helloworld.html returns nothing at all:
You should not need to add src="src/helloworld.js" in the tag. Otherwise the will try to load your helloworld.js (which causes your second question). I have created a plunker - it works without the src="src/helloworld.js"
html file:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Hello React!</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.0/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.0/react-dom.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.34/browser.min.js"></script>
</head>
<body>
<div id="example"></div>
<script type="text/babel">
ReactDOM.render(
<div>test</div>,
document.getElementById('example')
);
</script>
</body>
</html>
Demo:
http://plnkr.co/edit/ONtPtVkCsnEqNYYtDFAv?p=preview
For your second question. I guess you try to separate the script to a new file out from the helloworld.html. You do not need import because you add the react.js and react-dom.js in the html's head tag already. ReactDOM.render is already known when you load the src/helloworld.js from the script tag.
html file:
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Hello React!</title>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.0/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.3.0/react-dom.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.34/browser.min.js"></script>
</head>
<body>
<div id="example"></div>
<script type="text/babel" src="src/helloworld.js">
</script>
</body>
</html>
src/helloworld.js
ReactDOM.render(
<h1>Hello, world</h1>,
document.getElementById('example')
);
Demo:
http://plnkr.co/edit/9uNkyaz65A4FMTHwdCtr?p=preview
Edit:
Click on the browser, for example, I clicked Chrome and got Hello World!:

Resources