clipboard-helper.js

// This function must be called in a visible page, such as a browserAction popup
// or a content script. Calling it in a background page has no effect!
function FormatLink_copyTextToClipboard(text) {
  function oncopy(event) {
    document.removeEventListener("copy", oncopy, true);
    // Hide the event from the page to prevent tampering.
    event.stopImmediatePropagation();

    // Overwrite the clipboard content.
    event.preventDefault();
    event.clipboardData.setData("text/plain", text);
  }
  document.addEventListener("copy", oncopy, true);

  // Requires the clipboardWrite permission, or a user gesture:
  document.execCommand("copy");
}

function FormatLink_formatLinkAsText(format, newline, linkUrl, linkText) {
  function getFirstLinkInSelection(selection) {
    return selection.anchorNode.parentNode.href;
  }

  function formatURL(format, url, title, selectedText, newline) {
    let text = '';
    let work;
    let i = 0, len = format.length;

    function parseLiteral(str) {
      if (format.substr(i, str.length) === str) {
        i += str.length;
        return str;
      } else {
        return null;
      }
    }

    function parseString() {
      let str = '';
      if (parseLiteral('"')) {
        while (i < len) {
          if (parseLiteral('\\')) {
            if (i < len) {
              str += format.substr(i++, 1);
            } else {
              throw new Error('parse error expected "');
            }
          } else if (parseLiteral('"')) {
            return str;
          } else {
            if (i < len) {
              str += format.substr(i++, 1);
            } else {
              throw new Error('parse error expected "');
            }
          }
        }
      } else {
        return null;
      }
    }

    function processVar(value) {
      let work = value;
      while (i < len) {
        if (parseLiteral('.s(')) {
          let arg1 = parseString();
          if (arg1 && parseLiteral(',')) {
            let arg2 = parseString();
            if (arg2 && parseLiteral(')')) {
              let regex = new RegExp(arg1, 'g');
              work = work.replace(regex, arg2);
            } else {
              throw new Error('parse error');
            }
          } else {
            throw new Error('parse error');
          }
        } else if (parseLiteral('}}')) {
          text += work;
          return;
        } else {
          throw new Error('parse error');
        }
      }
    }

    while (i < len) {
      if (parseLiteral('\\')) {
        if (parseLiteral('n')) {
          text += newline;
        //  isWindows ? "\r\n" : "\n";
        } else if (parseLiteral('t')) {
          text += "\t";
        } else {
          text += format.substr(i++, 1);
        }
      } else if (parseLiteral('{{')) {
        if (parseLiteral('title')) {
          processVar(title);
        } else if (parseLiteral('url')) {
          processVar(url);
        } else if (parseLiteral('text')) {
          processVar(selectedText ? selectedText : title);
        }
      } else {
        text += format.substr(i++, 1);
      }
    }
    return text;
  }

  let title = document.title;
  let text = linkText;
  let href = linkUrl;
  let selection = window.getSelection();
  if (selection.rangeCount > 0) {
    let selectionText = selection.toString().trim();
    if (!text && selectionText) {
      text = selectionText;
    }

    let hrefInSelection = getFirstLinkInSelection(selection);
    if (!href && hrefInSelection) {
      href = hrefInSelection;
    }
  }
  if (!text) {
    text = title;
  }
  if (!href) {
    href = window.location.href;
  }

  return formatURL(format, href, title, text, newline);
}