Render saved JSON to HTML

// Run on your backend. email.json is the complete saved EmailDocument.
import { readFile } from 'node:fs/promises';
import type { EmailDocument } from '@weavour/editor';

async function renderSavedEmail(
  document: EmailDocument,
  mergeValues: Record<string, string> = {},
  conditionValues: Record<string, boolean> = {},
) {
  const editorKey = 'YOUR_PUBLIC_EDITOR_KEY';
  const response = await fetch(
    `https://api.weavour.com/editors/${editorKey}/render`,
    {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({ document, mergeValues, conditionValues }),
    },
  );
  const result = await response.json();
  if (!response.ok) {
    throw Object.assign(new Error(result.error ?? 'Email rendering failed'), {
      status: response.status,
      issues: result.issues,
      retryAfter: response.headers.get('Retry-After'),
    });
  }
  return result as {
    html: string;
    text: string;
    subject: string;
    preheader: string;
    rendererVersion: string;
  };
}

const savedEmail: EmailDocument = JSON.parse(await readFile('./email.json', 'utf8'));
const { html, text, subject, preheader } = await renderSavedEmail(
  savedEmail,
  { first_name: 'Alex' }, // Use the stable IDs of tags in your document.
);
// Submit these fields through your own email delivery provider.
console.log(html);

// Evaluate your application's rules before calling the renderer.
const output = await renderSavedEmail(
  savedEmail,
  { first_name: 'Alex' },
  { free_account: true }, // Condition ID -> boolean, never an expression.
);
// output.html and output.text contain only matching layouts.