reactjs

How can I correctly wrap few TD tags for JSXTransformer?


I have an array with items and I want to make something like this:

<tr>
(until have items in array
<td></td><td></td>)
</tr>

But if I do that, I get an JSXTransformer error :

Adjacent XJS elements must be wrapped in an enclosing tag

Working version:

{rows.map(function (rowElement){
    return (<tr key={trKey++}>
        <td className='info' key={td1stKey++}>{rowElement.row[0].value}</td><td key={td2ndKey++}>{rowElement.row[0].count}</td>
        <td className='info' key={td1stKey++}>{rowElement.row[1].value}</td><td key={td2ndKey++}>{rowElement.row[1].count}</td>
        <td className='info' key={td1stKey++}>{rowElement.row[2].value}</td><td key={td2ndKey++}>{rowElement.row[2].count}</td>
        <td className='info' key={td1stKey++}>{rowElement.row[3].value}</td><td key={td2ndKey++}>{rowElement.row[3].count}</td>
        <td className='info' key={td1stKey++}>{rowElement.row[4].value}</td><td key={td2ndKey++}>{rowElement.row[4].count}</td>
                 .......
        </tr>);
})}

I tried this one. But with <div> enclosing tag it doesn't work fine.

Answer here: Uncaught Error: Invariant Violation: findComponentRoot(..., ...$110): Unable to find element. This probably means the DOM was unexpectedly mutated

<tbody>
    {rows.map(function (rowElement){
        return (<tr key={trKey++}>
        {rowElement.row.map(function(ball){
            console.log('trKey:'+trKey+' td1stKey'+td1stKey+' ball.value:'+ball.value+' td2ndKey:'+td2ndKey+' ball.count:'+ball.count);
            return(<div key={divKey++}>
                <td className='info' key={td1stKey++}>{ball.value}</td><td key={td2ndKey++}>{ball.count}</td>
            </div>);
        })}
        </tr>);
    })}
</tbody>

Please, advise me how to properly wrap few TD tags! I tried use a guide Dynamic Children, but JSXTransformer doesn't allow me do that.


Solution

  • The following error usually occurs when you are returning multiple elements without a wrapping element

    Adjacent XJS elements must be wrapped in an enclosing tag

    Like

    return (
        <li></li>
        <li></li>
    );
    

    This doesn't work because you are effectively returning two results, you need to only ever be returning one DOM node (with or without children) like

    return (
        <ul>
            <li></li>
            <li></li>
        </ul>
    );
    
    // or 
    
    return (<ul>
        {items.map(function (item) {
            return [<li></li>, <li></li>];
        })}
    </ul>);
    

    I tried to guess what you're trying to do and here's a JSFiddle of it working.

    When using the div as a wrapper its actually never rendered to the DOM (not sure why).

    <tr data-reactid=".0.0.$1">
        <td class="info" data-reactid=".0.0.$1.$0.0">1</td>
        <td data-reactid=".0.0.$1.$0.1">2</td>
        <td class="info" data-reactid=".0.0.$1.$1.0">1</td>
        <td data-reactid=".0.0.$1.$1.1">2</td>
        <td class="info" data-reactid=".0.0.$1.$2.0">1</td>
        <td data-reactid=".0.0.$1.$2.1">2</td>
        <td class="info" data-reactid=".0.0.$1.$3.0">1</td>
        <td data-reactid=".0.0.$1.$3.1">2</td>
    </tr>
    

    EDIT: React 16+

    Since React 16 you can now use fragments.

    You would do it like this now

    return <>
        <li></li>
        <li></li>
    <>;
    

    Or you can use <React.Fragment>, <> is shorthand for a HTML fragment, which basically is just a temporary parent element that acts as a container, once its appended to the document it no longer exists.

    https://reactjs.org/docs/fragments.html

    https://developer.mozilla.org/en-US/docs/Web/API/DocumentFragment