Compose Message Headers - Experimental Webextention API for Thunderbird

Experimental webextention api to modify message headers

There are the following functions:

• browser.composeMessageHeaders.addComposeHeader(tabId, headerName, headerValue) Sets the header with name headerName with the value headerValue in the message inside the tabId
• browser.composeMessageHeaders.deleteComposeHeader(tabId, headerName) Deletes the headerline of header with name headerName in the message inside the tabId

Example usage:

function setMyHeaderValue( event, tabId ) {
    if(event.target.value) {
      console.log('Set myheader header to: ' + event.target.value);
      browser.composeMessageHeaders.addComposeHeader(tabId, 'X-MYHEADER', event.target.value);
    } else {
      console.log('Remove myheader');
      browser.composeMessageHeaders.deleteComposeHeader(tabId, 'X-MYHEADER');
    }

    return false;
};


// Set onchange to a select in popup.html with id `input-headerid`
browser.tabs.query({
  active: true,
  currentWindow: true,
}).then(tabs => {
  let tabId = tabs[0].id;
  let input = document.getElementById("input-headerid");
  input.addEventListener("change", () => setMyHeaderValue(event, tabId)) ;
});