Janky server-side rendering of prosemirror docs

render.js

const _ = require('lodash');
const cuid = require('cuid');

function renderText(renderBranch, renderLeaf) {
  return (acc, node) => {
    if (node.doc) {
      return renderText(renderBranch, renderLeaf)(acc, node, node.doc);
    } else if (node.content) {
      return renderBranch(acc, node, node.content);
    } else if (node.text) {
      return renderLeaf(acc, node, node.text, node.marks);
    } else {
      return acc;
    }
  };
}

const toPlaintext = renderText(
  (acc, node, childNodes) => acc + _.reduce(childNodes, toPlaintext, ''),
  (acc, node, text) => acc + text
);

const toHTML = renderText(
  (acc, node, childNodes) => acc + _.reduce(childNodes, toHTML, ''),
  (acc, node, text, marks) => {
    if (marks) {
      return acc + marks.map((m) => `<${m.type}>`).join('') + text + marks.map((m) => `</${m.type}>`).join('');
    } else {
      return acc + text;
    }
  }
);

function getKindOfTexture(type) {
  const kinds = {
    em: 'style.italics',
    strong: 'style.bold'
  };

  return kinds[type];
}

// Texture is a lossy format similar to Quill's deltas, 
// where the text is represented by a flat string and nodes/marks
// are 'textures' that have start and end indices
const toTexture = renderText(
  (acc, node, childNodes) => {
    if (node.type === 'paragraph') {
      acc.textures.push({
        length: _.reduce(childNodes, (length, child) => length + child.text.length, 0),
        kind: 'style.paragraph',
        id: cuid(),
        offset: acc.text.length
      });
    }

    return _.reduce(childNodes, toTexture, acc);
  },
  (acc, node, text, marks) => {

    if (marks) {
      marks.forEach((mark) => {
        acc.textures.push({
          length: text.length,
          kind: getKindOfTexture(mark.type),
          id: cuid(),
          offset: acc.text.length
        });
      });
    }

    acc.text += text;
    return acc;
  }
);

/**
 * Render prosemirror's data model in various formats.
 *
 * @param  {Object} field
 * @param  {string} format
 * @return {string|Object}
 */
function renderTo(field, format) {
  switch (format) {
  case 'TEXT_RAW': return field;
  case 'TEXT_HTML': return _.reduce([field], toHTML, '');
  case 'TEXT_TEXTURE': return _.reduce([field], toTexture, {text: '', textures: []});
  default: return _.reduce([field], toPlaintext, '');
  }
}

module.exports.renderTo = renderTo;