Function addRootBlocks

modules/tinymce/src/core/main/ts/api/html/DomParser.ts:418–468

(rootNode: AstNode, rootBlockName: string)

  };

  const addRootBlocks = (rootNode: AstNode, rootBlockName: string): void => {
    const blockElements = extend(makeMap(extraBlockLikeElements), schema.getBlockElements());
    const startWhiteSpaceRegExp = /^[ \t\r\n]+/;
    const endWhiteSpaceRegExp = /[ \t\r\n]+$/;

    let node = rootNode.firstChild, rootBlockNode: AstNode | null = null;

    // Removes whitespace at beginning and end of block so:
    // <p> x </p> -> <p>x</p>
    const trim = (rootBlock: AstNode | null) => {
      if (rootBlock) {
        node = rootBlock.firstChild;
        if (node && node.type === 3) {
          node.value = node.value?.replace(startWhiteSpaceRegExp, '');
        }

        node = rootBlock.lastChild;
        if (node && node.type === 3) {
          node.value = node.value?.replace(endWhiteSpaceRegExp, '');
        }
      }
    };

    // Check if rootBlock is valid within rootNode for example if P is valid in H1 if H1 is the contentEditable root
    if (!schema.isValidChild(rootNode.name, rootBlockName.toLowerCase())) {
      return;
    }

    while (node) {
      const next = node.next;

      if (isWrappableNode(blockElements, node)) {
        if (!rootBlockNode) {
          // Create a new root block element
          rootBlockNode = new AstNode(rootBlockName, 1);
          rootBlockNode.attr(defaultedSettings.forced_root_block_attrs);
          rootNode.insert(rootBlockNode, node);
          rootBlockNode.append(node);
        } else {
          rootBlockNode.append(node);
        }
      } else {
        trim(rootBlockNode);
        rootBlockNode = null;
      }

      node = next;
    }

    trim(rootBlockNode);
  };

  /**
   * Parses the specified HTML string into a DOM like node tree and returns the result.