javascript google-chrome google-chrome-extension

Chrome extension for sending WhatsApp messages with name

I'm trying to create a chrome extension for sending messages. I just want to add my name above the messages.

The problem is that I don't know how to send my name that comes from the variable (nomeAtendente).

I would be very grateful for any help, as I've been searching for how to do this on the internet for a few days now and haven't found anything.

const interval = setInterval(() => {
    const menu = document.querySelector("#app > div > div > div._2Ts6i._3RGKj > header > div._604FD > div > span > span");
    const content = document.querySelector("#app > div > div > div._2Ts6i._2xAQV");

    if (menu && content) {
        clearInterval(interval);

        const btnMenu = document.createElement("button");
        btnMenu.innerHTML = "7C";
        btnMenu.classList.add("btnMenu7Carros");
        menu.appendChild(btnMenu);



        const divLateralHTML = `
            Nome do atendente: <br>
            <input type="text" id="nomeAtendente">

            <br><br>
            <button id="buttonSalvar" name="button" class="">Salvar</button>
        `;
        content.insertAdjacentHTML('afterend', `<div id="divLateral" style="display: none;">${divLateralHTML}</div>`);


        //Abre e fecha o menu.
        const divLateral = document.getElementById("divLateral");
        let divLateralVisivel = false;
        btnMenu.addEventListener("click", function () {
            divLateralVisivel = !divLateralVisivel;
            divLateral.style.display = divLateralVisivel ? "block" : "none";
        });


        //Salva os dados
        const buttonSalvar = document.getElementById("buttonSalvar");
        buttonSalvar.addEventListener("click", function () {
            localStorage.setItem("nomeAtendente", document.getElementById("nomeAtendente").value);
            alert("Salvo com sucesso!")
        });
        // Obtém o valor do localStorage e define no input
        document.getElementById("nomeAtendente").value = localStorage.getItem('nomeAtendente') || "";



        const nomeAtendente = localStorage.getItem("nomeAtendente");





        document.addEventListener("keydown", function (e) {
            handleEvent(e);
        });

        document.addEventListener("keyup", function (e) {
            handleEvent(e);
        });

        document.addEventListener("keypress", function (e) {
            handleEvent(e);
        });

        function handleEvent(e) {
            const elemento = document.querySelector("#main > footer > div._2lSWV._3cjY2.copyable-area > div > span:nth-child(2) > div > div._1VZX7 > div._3Uu1_ > div > div > p > span");

            if (elemento !== null) {
                mensagemOriginal = elemento.textContent.trim();
                localStorage.setItem("mensagemOriginal", mensagemOriginal);
                //console.log("Original: " + mensagemOriginal);
            }


            if (e.key === "Enter" || e.code === "Enter") {
                mensagemOriginal = localStorage.getItem('mensagemOriginal') || ""
                const novaMensagem = `*[${nomeAtendente}]*\n${mensagemOriginal}`;
                console.log(novaMensagem);


                var elementoRemover = document.querySelector("#main > footer > div._2lSWV._3cjY2.copyable-area > div > span:nth-child(2) > div > div._1VZX7 > div._3Uu1_ > div > div.lhggkp7q.qq0sjtgm.jxacihee.c3x5l3r8.b9fczbqn.t35qvd06.m62443ks.rkxvyd19.c5h0bzs2.bze30y65.kao4egtt.kh4n4d4z.tt14wmjx");
                if (elementoRemover) {
                    elementoRemover.parentNode.removeChild(elementoRemover);
                }

                // Selecione o elemento com a classe "selectable-text" e classe "copyable-text"
                var elementoModificar = document.querySelector("#main > footer > div._2lSWV._3cjY2.copyable-area > div > span:nth-child(2) > div > div._1VZX7 > div._3Uu1_ > div > div > p");
                if (elementoModificar) {
                    elementoModificar.innerHTML = elementoModificar.innerHTML.replace(/<br>/g, '');
                
                    elementoModificar.innerHTML += `<span class="selectable-text copyable-text" data-lexical-text="true">${novaMensagem}</span>`;
                }



                localStorage.setItem("mensagemOriginal", "");
            }
        }


    }
}, 1000);

Solution

My first thought was to hook the function WhatsApp Web used to submit the message, or change the internal state of the app. Unfortunately I was not able to actually pin-point them after fiddling with the page.

What I tried after, which seems to work, is this:

get the editor element
add a 'keydown' event listener (with 'capture:true')
handle Enter keypress, and modify the message

const editorElement = document.querySelector('#main div[data-lexical-editor]');

function modifyMessage() {
  const editorSpan = editorElement.querySelector('span[data-lexical-text]'); // get span[data-lexical-text]
  console.log('editorSpan:', editorSpan);
  if (editorSpan) { // might not exist if the input field is empty
    const origMessage = editorSpan.childNodes[0].data; // get original message from text node (first child)
    const newMessage = '*AUTHOR*\n' + origMessage;
    editorSpan.childNodes[0].data = newMessage; // alter it!
    console.log('origMessage:', `"${origMessage}"`, 'newMessage:', `"${editorSpan.childNodes[0].data}"`);
    console.log('origMessage:', `"${origMessage}"`, 'newMessage:', `"${editorSpan.childNodes[0].data}"`);
  }
}

function handleEvent(e) {
  console.log('handleEvent:', e);
  if (e.type === 'keydown') {
    if (e.key === 'Enter') {
      modifyMessage();
    }
  }
}

const USE_CAPTURE = true;
editorElement.addEventListener('keydown', handleEvent, {capture:USE_CAPTURE}); // NOTE: 'capture:true' may be needed in this case, to ensure the key event is captured before WA handles it */
// editorElement.removeEventListener('keydown', handleEvent, USE_CAPTURE);

With a few adjustments the same logic could be used to handle 'onClick' on the send button.

Hopefully this is helpful, or at least a good starting point. ;D

UPDATE #0

And that ~would work for a single chat... but what if you selected another chat?!

Enter MutationObserver...

UPDATE #1

The MutationObserver API let's you listen for changes to the DOM and react to them.

With the following code we listen for a new chat element being added to the DOM (matching the '#main' selector), and wire the events to the new editor element.

// ~SAME CODE AS BEFORE

function modifyMessage() {
  const editorSpan = editorElement.querySelector('span[data-lexical-text]'); // get span[data-lexical-text]
  console.log('editorSpan:', editorSpan);
  if (editorSpan) { // might not exist if the input field is empty
    const origMessage = editorSpan.childNodes[0].data; // get original message from text node (first child)
    const newMessage = '*AUTHOR* 😎\n' + origMessage;
    editorSpan.childNodes[0].data = newMessage; // alter it!
    console.log('origMessage:', `"${origMessage}"`, 'newMessage:', `"${editorSpan.childNodes[0].data}"`);
  }
}

function handleEvent(e) {
  console.log('handleEvent:', e);
  if (e.type === 'keydown') {
    if (e.key === 'Enter') {
      modifyMessage();
    }
  }
}

// NEW CODE

function waitForElement(selector, callback) {
  // check if element matching selector is already in the DOM
  let matchedElement = document.querySelector(selector);
  if (matchedElement) {
    callback(matchedElement);
  } 
  
  // setup a MutationObserver that listens to changes to the DOM
  let mutObserver = new MutationObserver((mutationRecords, observer) => {
    for (const mutation of mutationRecords) {
      for (const addedNode of mutation.addedNodes) {
        if (addedNode.matches(selector)) {
          callback(addedNode);
        }
      }
    }
  });
  const options = {
    childList: true,
    subtree: true,
  };
  mutObserver.observe(document.documentElement, options);
  
  return mutObserver; // so that you can call .disconnect() to stop observing
}

let editorElement = null; // this will store the editorElement for the current chat

// watch for chat change
let observer = waitForElement('#main', (matchedElement) => { 
  console.log('matched (new chat clicked):', matchedElement);
  let newEditorElement = document.querySelector('#main div[data-lexical-editor]');
  if (editorElement != newEditorElement) { // check if it's actually a different editorElement
    editorElement = newEditorElement;
    console.log('new editorElement:', editorElement);

    const USE_CAPTURE = true;
    editorElement.addEventListener('keydown', handleEvent, {capture:USE_CAPTURE}); // NOTE: 'capture:true' may be needed in this case, to ensure the key event is captured before WA handles it */
    // editorElement.removeEventListener('keydown', handleEvent, USE_CAPTURE);
  }
});
// observer.disconnect();

UPDATE #2

Slightly altered code.

Now the approach is to listen for added nodes inside the right panes (matched by '._2xAQV' - check if that's the case on your end too), and rewire the events as needed.

Also adds/removes a click event listener to the send buttons, and keydown events on the correct text-inputs (should work for attachments too now).

// ~SAME CODE AS BEFORE

function modifyMessage() {
  const editorSpan = editorElement.querySelector('span[data-lexical-text]'); // get span[data-lexical-text]
  console.log('editorSpan:', editorSpan);
  if (editorSpan) { // might not exist if the input field is empty
    const origMessage = editorSpan.childNodes[0].data; // get original message from text node (first child)
    const newMessage = '*AUTHOR* 😎\n' + origMessage;
    editorSpan.childNodes[0].data = newMessage; // alter it!
    console.log('origMessage:', `"${origMessage}"`, 'newMessage:', `"${editorSpan.childNodes[0].data}"`);
  }
}

function handleEvent(e) {
  console.log('handleEvent:', e);
  if ((e.type === 'keydown' && e.key === 'Enter') || e.type === 'click') {
    modifyMessage();
  }
}

// SLIGHTLY MODIFIED CODE (should also handle send button and text messages below images)

function waitForElement(selector, callback) {
  // check if element matching selector is already in the DOM
  let matchedElement = document.querySelector(selector);
  if (matchedElement) {
    callback(matchedElement);
  } 
  
  // setup a MutationObserver that listens to changes to the DOM
  let mutObserver = new MutationObserver((mutationRecords, observer) => {
    for (const mutation of mutationRecords) {
      if (mutation.addedNodes?.length > 0) console.log('addedNodes:', mutation.addedNodes);
      for (const addedNode of mutation.addedNodes) {
        if (addedNode.matches(selector)) {
          callback(addedNode);
        }
      }
      /*if (mutation.removedNodes?.length > 0) console.log('removedNodes:', mutation.removedNodes);
      for (const removedNode of mutation.removedNodes) {
        if (removedNode.matches(selector)) {
          callback(removedNode);
        }
      }*/
    }
  });
  const options = {
    childList: true,
    subtree: true,
  };
  mutObserver.observe(document.documentElement, options);
  
  return mutObserver; // so that you can call .disconnect() to stop observing
}

let editorElement = null; // this will store the editorElement for the current chat
let sendButtonElement = null; // this will store the sendButtonElement for the current chat

// watch for changes to the DOM (for elements added inside "._2xAQV" (which match the right panes))
let observer = waitForElement('._2xAQV *', (matchedElement) => {
  console.log('matchedElement:', matchedElement);
  
  // editor
  const editorSelector = '._2xAQV .lexical-rich-text-input'; //'#main div[data-lexical-editor]'
  let newEditorElement = document.querySelector(editorSelector);
  if (editorElement != newEditorElement) { // check if it's actually a different editorElement
    editorElement = newEditorElement;
    console.log('new editorElement:', editorElement);

    const USE_CAPTURE = true;
    if (editorElement) editorElement.removeEventListener('keydown', handleEvent, USE_CAPTURE); // remove event listener
    editorElement.addEventListener('keydown', handleEvent, {capture:USE_CAPTURE}); // NOTE: 'capture:true' may be needed in this case, to ensure the key event is captured before WA handles it */
  }

  // send button
  const sendButtonSelector = '._2xAQV span[data-icon="send"]'; //'#main div[data-lexical-editor]'
  let newSendButtonElement = document.querySelector(sendButtonSelector)?.parentElement;
  if (sendButtonElement != newSendButtonElement) { // check if it's actually a different sendButtonElement
    sendButtonElement = newSendButtonElement;
    console.log('new newSendButtonElement:', sendButtonElement);

    const USE_CAPTURE = true;
    if (sendButtonElement) sendButtonElement.removeEventListener('click', handleEvent, USE_CAPTURE); // remove event listener
    sendButtonElement.addEventListener('click', handleEvent, {capture:USE_CAPTURE}); // NOTE: 'capture:true' may be needed in this case, to ensure the click event is captured before WA handles it */
  }
});
// observer.disconnect();

Could be refactored a bit, but you should get the gist of it. Anyway let me know if it works for you.