React - pass props/state to rendered HTML string? - reactjs

Question

In my React app, I have stored a text template as an HTML string on the server which is passed up to the client to be rendered. Is it possible to render this HTML string in such a way that it can access it's parent component state/props? I've tried using dangerouslySetInnerHTML and ReactDOMServer.renderToString(), both of which render the string as HTML, but render {props.text} as a literal string, rather than a reference to the component's props.
For example, on the server I have stored:
<div>Welcome to my app</div>
<div>{props.message}</div>
<div>Have fun</div>
And the component
import React from "react"
import { connect } from "react-redux"
const mapStateToProps = (state) => {
return { state }
},
WelomeBody = (props) => {
return (
<div dangerouslySetInnerHTML={{"__html": props.state.welcomeMessageBody}} />
)
}
export default connect(mapStateToProps, null)(WelomeBody)
but this results in:
Welcome to my app
{props.message}
Have fun
Is there a way that this can be rendered so as to access the value of props.message, rather than just rendering it literally?

Answer 1

If what you have in mind is to send down a React component (in JSX syntax) from your server to your client and have the client somehow rehydrate/compile it into an actual, working component, this is not achievable that easily.
When you build and bundle your React app, only components that are statically referenced/imported in your application at compile time can be used at runtime on the browser.
So, in order to dynamically render a component from a template and embed variables into it, your choices are:
Render it into final HTML on your server, send down that HTML and have a simple React component perform dangerouslySetInnerHTML for it. But, like you've already observed, that content has to be the full HTML code, no templates, variables, JSX, etc. Everything is string and HTML at this point, no more processing.
Alternatively, send down a Markdown document and have a Markdown component parse it into HTML and display it.
Create a sophisticated component that can receive a string, parse it, tokenize it, substitute values in it, etc. Essentially, create your own template-processing component that can read a template (the string sent down from your server) and embed the appropriate values into it.
A simple solution (to substitute values into a template) would be:
function Filler(props) {
let html = props.template;
Object.keys(props).forEach(key => {
if (key !== "template")
html = html.replace("{" + key + "}", props[key]);
});
return <div dangerouslySetInnerHTML={{__html: html}} />;
}
and use it like
<Filler template={"<h1>Hello, {firstname} {lastname}</h1>"} firstname="John" lastname="Doe" />
But again, this is far from a full-fledged actual React component.