Full msg: > react.js:18893 Uncaught Invariant Violation: Frame.render(): A valid React element (or null) must be returned. You may have returned undefined, an array or some other invalid object.
Here is my constructor for collumns, i got error when try to parse this array that contain elements for creating html elements
makeCollumns: function(num, obj){
// CHECKED THAT OBJ HAVE CORRECT DATA
console.log("obj[0].username= " + obj[0].username );
// ALSO CHECKED THAT NUM HAVE CORRECT INTEGER
console.log("num: " + num);
function collumn(i, data){
return(
<div className={'row rOw-' + i}>
<div className="col-xs-1">
{(i+1)}
</div>
<div className={'col-xs-5 user-name-'+ i}>
{data.username}
</div>
<div className={'col-xs-3 user-montly-'+ i}>
{data.recent}
</div>
<div className={'col-xs-3 user-alltime-'+ i}>
{data.alltime}
</div>
</div>
);
}
var markupPredefined = [];
for ( let i = 0 ; i < num; i ++ )
markupPredefined.push(collumn(i, obj[i]));
return markupPredefined;
}
EDIT: Code:
http://codepen.io/ustvarno/pen/VjKGqo/
solve it, by putting brackets around returned array {} so children in array can be evaluated to JSX