React props: Using an HTML entity within JSX dynamic content?

Question

I have a React component, to whose props I want to assign a string that includes both JavaScript variables and HTML entities.

Some of the approaches I've attempted have resulted in the HTML entity being rendered escaped. For example, – gets rendered literally as "–" instead of as "–".

Is there a way to get an HTML entity to render unescaped in a JSX dynamic content block being assigned to a React props?

Attempts Made

Tried using a template literal:

<MyPanel title={`${name} &ndash; ${description}`}> ... </MyPanel>

Problem: In the rendered output, the – is being rendered literally as "–" instead of as "–".

---

Attempted to construct some simple JSX with no quotes:

<MyPanel title={{name} &ndash; {description}} ... </MyPanel>

Problem: This failed at compile time with a syntax error.

---

Tried working around the syntax error by wrapping the JSX in a <span /> element:

<MyPanel title={<span>{name} &ndash; {description}</span>} ... </MyPanel>

Problem: This works, but I'd rather avoid the superfluous <span /> element being present in the rendered output.

---

Tried replacing the HTML entity with a Unicode numeric character reference:

<MyPanel title={name + ' \u2013 ' + description} ... </MyPanel>

Problems:

• This works, but (in my opinion) makes the code a little less readable. (It's more obvious that "ndash" rather than "2013" represents an en-dash character.)
• Also, this involves +-operator concatenation, which triggers a Unexpected string concatenation prefer-template error in my team's JSLint checker; a solution that uses string interpolation instead would be better.

Answer 1

You can avoid the superfluous span with a Fragment:

<MyPanel title={<>{name} &ndash; {description}</>} ... </MyPanel>

This feature was introduced in React 16.2.

See the Documentation

---

I agree with @samanime that using the actual character is best for simple cases, but if your content is truly dynamic, I would prefer using a Fragment over either the entityToChar or dangerouslySetInnerHTML approaches.

Answer 2

Here are a few options (I outlined these in a more general answer awhile back):

1. Easiest - Use Unicode

   <MyPanel title={ `${name} – ${description}` } />
   

2. Safer - Use the Unicode number for the entity inside a Javascript string.

   <MyPanel title={`${name} \u2013 ${description}`} />
   

   or

   <MyPanel title={`${name} ${String.fromCharCode(8211)} ${description}`} />
   

3. Last Resort - Insert raw HTML using dangerouslySetInnerHTML.

   title={`${name} – ${description}`}
   

   with:

   <div dangerouslySetInnerHTML={{__html: props.title}}></div>
   

const MyPanel = (props) => {
  return (
    <div>{props.title}</div>
  )
}

const MyPanelwithDangerousHTML = (props) => {
  return (
    <div dangerouslySetInnerHTML={{__html: props.title}}></div>
  )
}

var description = "description";
var name = "name";

ReactDOM.render(<MyPanel title={`${name} – ${description}`} />
, document.getElementById("option1"));

ReactDOM.render(<MyPanel title={`${name} \u2013 ${description}`} />
, document.getElementById("option2"));

ReactDOM.render(<MyPanel title={`${name} ${String.fromCharCode(8211)} ${description}`} />
, document.getElementById("option3"));

ReactDOM.render(<MyPanelwithDangerousHTML title={`${name} &ndash; ${description}`} />
, document.getElementById("option4"));

<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/15.1.0/react-dom.js"></script>

<div id="option1"></div>
<div id="option2"></div>
<div id="option3"></div>
<div id="option4"></div>