: ctrl + z breaks after changing the value content through javascript</a></h1> </div> <div class="grid fw-wrap pb8 mb16 bb bc-black-075"> <div class="grid--cell ws-nowrap mr16 mb8" title="2016-01-12 19:07:53Z"> <span class="fc-light mr2">Asked</span> <time itemprop="dateCreated" datetime="2021-09-21T14:28:19.670" class="fromnow">Sep 21 '21 at 14:28</time> </div> <div class="grid--cell ws-nowrap mr16 mb8"> <span class="fc-light mr2">Active</span> <time class="fromnow" title="2021-09-21T14:55:18.817" datetime="2021-09-21T14:55:18.817">Sep 21 '21 at 14:55</a> </div> <div class="grid--cell ws-nowrap mb8" title="Viewed 962 times"> <span class="fc-light mr2">Viewed</span> 962 times </div> </div> <div id="mainbar" role="main" aria-label="questions and answers"> <div id="question" class="question" data-questionid="69270721" data-ownerid="6845809" data-score="4"> <div class="post-layout"> <div class="votecell post-layout--left"> <div class="js-voting-container grid jc-center fd-column ai-stretch gs4 fc-black-200" data-post-id="69270721"> <button class="js-vote-up-btn grid--cell s-btn s-btn__unset c-pointer"><svg aria-hidden="true" class="m0 svg-icon iconArrowUpLg" width="36" height="36" viewBox="0 0 36 36"><path d="M2 26h32L18 10 2 26z"></path></svg></button> <div class="js-vote-count grid--cell fc-black-500 fs-title grid fd-column ai-center" itemprop="upvoteCount" data-value="4">4</div> <button class="js-bookmark-btn s-btn s-btn__unset c-pointer py4"> <svg aria-hidden="true" class="svg-icon iconBookmark" width="18" height="18" viewBox="0 0 18 18"><path d="M6 1a2 2 0 00-2 2v14l5-4 5 4V3a2 2 0 00-2-2H6zm3.9 3.83h2.9l-2.35 1.7.9 2.77L9 7.59l-2.35 1.7.9-2.76-2.35-1.7h2.9L9 2.06l.9 2.77z"></path></svg> <div class="js-bookmark-count mt4" data-value=""></div> </button> </div> </div> <div class="postcell post-layout--right"> <div class="s-prose js-post-body" itemprop="text"><p>I am making an HTML textarea that accepts <code>tab</code> key input using JavaScript.<br/> When I searched for a solution on the web, I found <a href="../../questions/6637341/use-tab-to-indent-in-textarea">this answer</a>, but after some fiddling, I found out that <code>ctrl+z</code> stops working after I hit <code>tab</code> key.</p> <p>Doing some more experiments revealed that changing the value attribute was likely the culprit of this problem. Here is a small scale code example that you can hopefully reproduce this behavior yourself.<br/> <a class="external-link" href="https://codepen.io/MartianLord/pen/gORKPGp?editors=1010" rel="nofollow noreferrer">https://codepen.io/MartianLord/pen/gORKPGp?editors=1010</a><br/> I managed to find a workaround using <code>document.execCommand</code> to simulate the user input, but this method is deprecated <a class="external-link" href="https://developer.mozilla.org/en-US/docs/Web/API/Document/execCommand" rel="nofollow noreferrer">as you can see here</a>, so I am looking for a more up to date solution.</p></div> <div class="mt24 mb12"> <div class="post-taglist grid gs4 gsy fd-column"> <div class="grid ps-relative"> <a href="../../questions/tagged/javascript" class="post-tag js-gps-track" title="show questions tagged 'javascript'" rel="tag">javascript</a> <a href="../../questions/tagged/html" class="post-tag js-gps-track" title="show questions tagged 'html'" rel="tag">html</a> </div> </div> </div> <div class="mb0"> <div class="mt16 grid gs8 gsy fw-wrap jc-end ai-start pt4 mb16"> <div class="grid--cell mr16 fl1 w96"></div> <div class="post-signature grid--cell"> <div class="user-info "> <div class="user-action-time">edited <span title="2021-09-21T14:37:50.663" class="relativetime">Sep 21 '21 at 14:37</span></div> <div class="user-gravatar32"></div> <div class="user-details" itemprop="author" itemscope="" itemtype="http://schema.org/Person"> <span class="d-none" itemprop="name">martian17</span> <div class="-flair"></div> </div> </div> </div> <div class="post-signature owner grid--cell"> <div class="s-user-card s-user-card"> <time class="s-user-card--time" datetime="asked Sep 21 '21 at 14:28">asked Sep 21 '21 at 14:28</time> <a href="../../users/6845809/martian17" class="s-avatar s-avatar__32 s-user-card--avatar"> <img class="s-avatar--image" src="../../users/profiles/6845809.webp" data-jdenticon-width="32" data-jdenticon-height="32" data-jdenticon-value="martian17" /> </a> <div class="s-user-card--info"> <a href="../../users/6845809/martian17" class="s-user-card--link">martian17</a> <ul class="s-user-card--awards"> <li class="s-user-card--rep" title="reputation score">418</li> <li class="s-award-bling s-award-bling__silver" title="3 silver badges">3</li> <li class="s-award-bling s-award-bling__bronze" title="14 bronze badges">14</li> </ul> </div> </div> </div> </div> </div> </div> <div class="post-layout--right js-post-comments-component"> <div id="comments-69270721" class="comments js-comments-container bt bc-black-075 mt12 " data-post-id="69270721" data-min-length="15"> <ul class="comments-list js-comments-list" data-remaining-comments-count="0" data-canpost="false" data-cansee="true" data-comments-unavailable="false" data-addlink-disabled="true"> <li id="comment-122434533" class="comment js-comment " data-comment-id="122434533" data-comment-owner-id="7178355" data-comment-score="2"> <div class="js-comment-actions comment-actions"> <div class="comment-score js-comment-edit-hide"> <span title="number of 'useful comment' votes received" class="warm">2</span> </div> </div> <div class="comment-text js-comment-text-and-form"> <a name="comment122434533_69270721"></a> <div class="comment-body js-comment-edit-hide"> <span class="comment-copy">I've worked in a solution long ago building a textfield to past and copy piece of code. Instead of `<textarea>` i've used `contentEditable` property. You should look if it fit in your project. https://developer.mozilla.org/pt-BR/docs/Web/Guide/HTML/Editable_content – Coffezilla Sep 21 '21 at 14:44

Answer 1

To support ctrl+z while using tab in <textarea>, you need to implement undo, redo functions to connect with <textarea>. When the <textarea> changes, record the changes in the history, and revert when ctrl+z key input occurs.

UndoRedojs is a library for this task.

I think there will be a lot of work to be done, such as setting the selection position, in order to fully implement it. I recommend using a text editor that has already been created.