How to render a formula in a template string

[ackh]

From the documentation I derived the following working example that works as expected:

<script>
  const formulaElement = document.getElementById("formula");
  const formula        = "c = \\pm\\sqrt{a^2 + b^2}"
  katex.render(formula, formulaElement, { throwOnError: false });
</script>

However, I'm trying to render a more sophisticated formula using a template string and cannot make it work. The code looks as follows:

<script>
  const formulaElement = document.getElementById("formula");
  const formula        = String.raw`
\begin{equation}
\begin{split}
a &= b + c \\
  &= e + f
\end{split}
\end{equation}
`;
  katex.render(formula, formulaElement, { throwOnError: false });
</script>

That second example does not render the formula but instead just prints it literally, i.e. all I'm getting in the web browser is the string \begin{equation} \begin{split} a &= b + c \\ &= e + f \end{split} \end{equation} instead of the actual rendering. What am I missing?

[ackh]

Alright, setting throwOnError to true emitted the error message KaTeX parse error: {equation} can be used only in display mode.. So I added displayMode: true. The working solution looks as follows:

<script>
  const formulaElement = document.getElementById("formula");
  const formula        = String.raw`
\begin{equation}
\begin{split}
a &= b + c \\
  &= e + f
\end{split}
\end{equation}
`;
  katex.render(formula, formulaElement, { displayMode: true, throwOnError: true });
</script>