chat-client/scripts/formatting.js

// This function was copied from https://stackoverflow.com/a/4835406/5302652
function escapeHtml(text) {
  var map = {
    '&': '&',
    '<': '&lt;',
    '>': '&gt;',
    '"': '&quot;',
    "'": '&#039;'
  };

  return text.replace(/[&<>"']/g, function(m) { return map[m]; });
}

// Get a list of links sent to the user
var sent_chat_links = [];

function open_link_id(id)
{
  // Open the saved link
  open(sent_chat_links[id]);
}

function is_url(text) {
  return /^(ftp|http|https):\/\/[^ "]+$/.test(text);
}

function text_to_html(text)
{
  // Make the text XSS safe
  text = escapeHtml(text);

  // Split the text into an array
  text = text.split(" ");

  // Some varibles for remembering parts of the string
  var underline_check = false;
  var strikethrough_check = false;
  var italic_check = false;
  var bold_check = false;
  var code_check = false;
  var ignore_check = 0;

  var last_word = "";

  // Create an out varible
  var out = "";

  // Loop over the rows
  for(var r=0;r<text.length;r++)
  {
    // Is this a URL
    if(is_url(text[r]))
    {
      // Push the link to the array
      sent_chat_links.push(text[r]);
      var id = sent_chat_links.length-1;

      // Display a link
      out += "<a href='#' onclick='open_link_id("+id+")'>"+text[r]+"</a>";
    }

    else
    {
      // Loop over the text
      for(var i=0;i<text[r].length;i++)
      {
        // Is the ignore check in place
        if(ignore_check > 0)
        {
          // Remove 1
          ignore_check -= 1;

          // Add the next character, ignoring the formatting
          out += text[r][i];
        }

        else
        {
          // Is the text a backslash (ignore)
          if(text[r][i] == "\\" && !code_check)
          {
            // Set ignore check
            ignore_check = 1;
          }

          // Is the text a dash (underline)
          if(text[r][i] == "-" && !code_check)
          {
            // Invert the varible
            underline_check = !underline_check;

            if(underline_check)
            {
              // Open the underline element
              out += "<u>";
            }

            else
            {
              // Close the underline element
              out += "</u>";
            }
          }

          // Is the text a star (bold)
          else if(text[r][i] == "*" && !code_check)
          {
            // Invert the varible
            bold_check = !bold_check;

            if(bold_check)
            {
              // Open the bold element
              out += "<b>";
            }

            else
            {
              // Close the bold element
              out += "</b>";
            }
          }

          // Is the text an underline (italic)
          else if(text[r][i] == "_" && !code_check)
          {
            // Invert the varible
            italic_check = !italic_check;

            if(italic_check)
            {
              // Open the bold element
              out += "<i>";
            }

            else
            {
              // Close the bold element
              out += "</i>";
            }
          }

          // Is the text a ~ (strikethrough)
          else if(text[r][i] == "~" && !code_check)
          {
            // Invert the varible
            strikethrough_check = !strikethrough_check;

            if(strikethrough_check)
            {
              // Open the strikethrough element
              out += "<del>";
            }

            else
            {
              // Close the strikethrough element
              out += "</del>";
            }
          }

          // Is this a newline
          else if(text[r][i] == "\n")
          {
            // Add a break
            out += "<br/>";
          }

          // Is this a code marker
          else if(text[r][i] == "`")
          {
            // Invert the varible
            code_check = !code_check;

            if(code_check)
            {
              // Open the code element
              out += "<code>";
            }

            else
            {
              // Close the code element
              out += "</code>";
            }
          }

          else
          {
            out += text[r][i];
          }
        }
      }
    }

    // Add a space
    out += " ";
  }

  // Close some unclosed elements
  if(bold_check) out += "</b>";
  if(italic_check) out += "</i>";
  if(underline_check) out += "</u>";
  if(strikethrough_check) out += "</del>";
  if(code_check) out += "</code>";

  console.log(out)

  // Send out back
  return out;
}