Change Paragraph Heading text in Google Docs using Google Scripts

Question

I have a Google Docs with the following style:

The actual TOC is:

You can see it has a few styles:

• Title (14pt, in blue, underlined)
• Subtitle (12pt, in black, underlined)
• Header 1 (11pt)
• Header 2 (10pt, in bold)
• Normal text (10pt)

I would like to make a script that runs on the active document and store the content of each heading to make the following changes:

• Header 1 (14pt, in blue, underlined)
• Header 2 (11pt)
• Normal text (10pt, the first line contains "Topic nº)" in bold)

The final result after running the script should be:

The new TOC should look like:

So the main change is to put HEADER 2 content into a Normal text line so it dissapears from TOC. Is there any way to code a script that solve this?

Answer 1

See script below:

function findHeader() {
  var doc = DocumentApp.getActiveDocument();
  var body = doc.getBody();
  // Define the search parameters
  var searchType = DocumentApp.ElementType.PARAGRAPH;
  var searchHeadings = [DocumentApp.ParagraphHeading.HEADING2, DocumentApp.ParagraphHeading.HEADING1, DocumentApp.ParagraphHeading.TITLE];
  var replacementHeadings = [DocumentApp.ParagraphHeading.NORMAL, DocumentApp.ParagraphHeading.HEADING2, DocumentApp.ParagraphHeading.HEADING1];
  var searchResult = null;
  
  // Style changes you want to apply
  var H2_N = {};
  H2_N[DocumentApp.Attribute.FONT_SIZE] = '11';
  // Since HEADING 2 that are made to be Normal becomes first Normal heading and first Normal heading is to be bold, 
  // You can directly make it bold here to reduce redundancy
  H2_N[DocumentApp.Attribute.BOLD] = true;

  var H1_H2 = {};
  H1_H2[DocumentApp.Attribute.FONT_SIZE] = '11';

  var T_H1 = {};
  T_H1[DocumentApp.Attribute.FONT_SIZE] = '14';
  T_H1[DocumentApp.Attribute.FOREGROUND_COLOR] = '#0000FF';
  T_H1[DocumentApp.Attribute.UNDERLINE] = true;

  var styles = [H2_N, H1_H2, T_H1];

  // Loop all searchHeadings
  searchHeadings.forEach((searchHeading, index) => {  
    // Search until the wanted searchHeading is found
    while (searchResult = body.findElement(searchType, searchResult)) {
      var par = searchResult.getElement().asParagraph();
      if (par.getHeading() == searchHeading) {
        // Replace with its corresponding replacementHeadings and apply approriate styles
        par.setHeading(replacementHeadings[index]);
        par.setAttributes(styles[index]);
      }
    }
  });
}

Script Behavior Summary:

• Demotes the following headings (T -> H1, H1 -> H2, H2 -> N)
• Applies different styles per demotion:
  • T -> H1: 14PT, BLUE, UNDERLINED
  • H1 -> H2: 11PT
  • H2 -> N: 11PT, BOLD
• H2 -> N is directly turned to bold as you want the first N paragraph to be bold. And when H2 is demoted, it turns into N and becomes the first N. So we can directly turn H2 into bold when demoted.

Output:

References:

• Paragraph Heading
• Attribute