I have some React code in the string, for example:
const component = `
function App() {
return (
<div>
test
</div>
);
}
`;
And I want to be able to render that component from within browser, something like:
import React, { Component } from 'react';
import { render } from 'react-dom';
import * as babel from 'babel-standalone';
const babelCode = babel.transform(component, { presets: ['react', 'es2015'] }).code;
render(eval(babelCode), document.getElementById('WorkFlow'));
This particular example doesn't work but it shows what I'm looking for, any help appreciated!
Thanks!
Babel produces the code with "use strict"
and eval()
doesn't work with it well. First, we should remove that line manually.
const code = babelCode.replace('"use strict";', "").trim();
Ideally, after this following lines should work.
eval(code);
render(<App/>, document.getElementById('WorkFlow'));
Note that you don't need to put eval()
inside render. It doesn't return your App function or anything. Instead, it will add App to context and we can use it after eval()
statement.
But usually, React app has a compile step with webpack
or similar tool and will complain about undefined App
.
As a workaround, we can wrap our component with a Function which returns our component itself. Now we can call this function to get our component. But the context of wrapping function doesn't have React
variable. So we have to pass it manually as a parameter. If you are going to use any other variable from the current context, you will have to pass those as well.
const code = babelCode.replace('"use strict";', "").trim();
const func = new Function("React", `return ${code}`);
const App = func(React)
render(<App/>, document.getElementById('WorkFlow'));
Hope this helps!
React will allow you to render either a Component
or an Element
. You can think of an Element
as a raw HTML code in JSX, while a Component
is a prototype, which inherits from React.Component
. In your code you are trying to render a result of evaluating the babel transpiled code, which will fail (I'm not sure what it is, but it's probably undefined
or null
). If you want to make it work, first evaluate the code and then invoke the function to pass the Element
code to the render
function:
eval(babelCode); // now the App function has been defined and you can use it in the code
render(App(), document.getElementById('WorkFlow'));
// ^^ here the App function is being invoked
Old answer (I thought you were trying to pass the component
as a file not and not as a variable to transpiler):
babel
will never transpile strings, so this is not going to work out for you. You can however consider using a raw JS
code instead of JSX
as your string content. More about it you can read here: https://facebook.github.io/react/docs/react-without-jsx.html