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SCR26: Inserting dynamic content into the Document Object Model immediately following its trigger element | WAI | W3C
<!DOCTYPE html><html lang="en" xml:lang="en" xmlns="http://www.w3.org/1999/xhtml"><head><title>SCR26: Inserting dynamic content into the Document Object Model immediately following its trigger element | WAI | W3C</title> <meta name="viewport" content="width=device-width, initial-scale=1"> <link rel="stylesheet" href="https://w3.org/WAI/assets/css/style.css"> <link rel="stylesheet" href="../base.css"> </head><body dir="ltr"> <a href="#main" class="button button--skip-link">Skip to content</a> <div class="minimal-header-container default-grid"> <header class="minimal-header" id="site-header"> <div class="minimal-header-name"> <a href="https://www.w3.org/WAI/WCAG22/Techniques/">WCAG 2.2 Techniques</a> </div> <div class="minimal-header-subtitle">Examples of ways to meet WCAG; not required</div> <a class="minimal-header-link" href="https://www.w3.org/WAI/WCAG22/Techniques/about">About WCAG Techniques</a> <div class="minimal-header-logo"> <a href="http://w3.org/" aria-label="W3C"> <svg 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45.5h-1.816l-2.784-9.355c-.41-1.394-.65-2.334-.722-2.823-.104.749-.332 1.71-.684 2.881L129.04 45.5h-1.817l-3.779-14.277h1.875l2.217 8.72c.3 1.14.527 2.272.684 3.399.143-1.068.397-2.237.761-3.506l2.52-8.613h1.855l2.627 8.681c.339 1.127.6 2.272.781 3.438.105-.899.336-2.038.694-3.418l2.207-8.701h1.875zm14.57 0l-1.718-4.424h-5.664l-1.7 4.424h-1.816l5.576-14.336h1.621l5.567 14.336zm-2.256-6.016l-1.601-4.326-.684-2.138c-.195.78-.4 1.494-.615 2.138l-1.621 4.326zm10.098 6.016h-5.156v-1.035l1.68-.381V32.658l-1.68-.4v-1.035h5.156v1.035l-1.68.4v11.426l1.68.38z"></path> </g> </g> </svg> </a> </div> </header> </div> <div class="default-grid with-gap leftcol"> <aside class="box nav-hack sidebar standalone-resource__sidebar"> <header class="box-h">Page Contents</header> <div class="box-i"> <nav aria-label="page contents" class="navtoc"> <ul><li><a href="#technique">About this Technique</a></li> <li><a href="#description">Description</a></li> <li><a href="#examples">Examples</a></li> <li><a href="#tests">Tests</a></li> </ul> </nav> </div> </aside> <main id="main" class="standalone-resource__main"> <h1><span>Technique SCR26:</span>Inserting dynamic content into the Document Object Model immediately following its trigger element</h1> <section id="technique" class="box"> <h2 class="box-h box-h-icon">About this Technique</h2> <div class="box-i"> <p> This technique relates to <a href="https://www.w3.org/WAI/WCAG22/Understanding/focus-order">2.4.3: Focus Order</a> (<strong>Sufficient</strong> when used for changing a Web page dynamically).</p> <p>This technique applies to HTML and script.</p> </div> </section> <section id="description"><h2>Description</h2> <p>The objective of this technique is to place inserted user interface elements into the Document Object Model (DOM) in such a way that the tab order and screen-reader reading order are set correctly by the default behavior of the user agent. This technique can be used for any user interface element that is hidden and shown, such as menus and dialogs.</p> <p>The reading order in a screen-reader is based on the order of the HTML elements in the Document Object Model, as is the default tab order. This technique inserts new content into the DOM immediately following the element that was activated to trigger the script. The triggering element must be a link or a button, and the script must be called from its <code class="language-javascript">onclick</code> event. These elements are natively focusable, and their <code class="language-javascript">onclick</code> event is device independent. Focus remains on the activated element and the new content, inserted after it, becomes the next thing in both the tab order and screen-reader reading order.</p> <p>Note that this technique works for synchronous updates. For asynchronous updates (sometimes called AJAX), an additional technique is needed to inform the assistive technology that the asynchronous content has been inserted. </p> </section><section id="examples"><h2>Examples</h2> <section class="example" id="example-1"><h3>Example 1</h3> <p>This example creates a menu when a link is clicked and inserts it after the link. The <code class="language-javascript">onclick</code> event of the link is used to call the ShowHide script, passing in an <code class="language-html">id</code> for the new menu as a parameter.</p> <pre xml:space="preserve"><code class="language-html"><button aria-expanded="false" type="button" onclick="ShowHide('foo',this)"> Toggle </button></code></pre> <p>The ShowHide script creates a <code class="language-html">div</code> containing the new menu, and inserts a link into it. The last line is the core of the script. It finds the parent of the element that triggered the script, and appends the div it created as a new child to it. This causes the new <code class="language-html">div</code> to be in the DOM after the menu. When the user hits tab, the focus will go to the first focusable item in the menu, the link we created.</p> <pre xml:space="preserve"><code class="language-javascript">function ShowHide(id,src){ var el = document.getElementById(id); if (!el){ el = document.createElement("div"); el.id = id; var link = document.createElement("a"); link.href = "/laptops"; link.appendChild(document.createTextNode("Laptops")); el.appendChild(link); src.parentElement.appendChild(el); src.setAttribute("aria-controls", id); src.setAttribute("aria-expanded", "true"); } else if (el && src.getAttribute("aria-expanded") === "false"){ el.style.display = 'block'; src.setAttribute("aria-expanded", "true"); } else{ el.style.display = 'none'; src.setAttribute("aria-expanded", "false"); } }</code></pre> <p>CSS is used to make the <code class="language-html">div</code> and link look like a menu.</p> </section> </section> <section id="tests"><h2>Tests</h2> <section class="procedure" id="procedure"><h3>Procedure</h3> <ol> <li>Find all areas of the page that trigger dialogs that are not pop-up windows.</li> <li>Check that the dialogs are triggered from the click event of a button or a link.</li> <li>Using a tool that allows you to inspect the DOM generated by script, check that the dialog is next in the DOM.</li> </ol> </section> <section class="results" id="expected-results"><h3>Expected Results</h3> <ul> <li>#2 and #3 are true.</li> </ul> </section> </section> <a class="button button-backtotop" href="#top"> <span> <svg focusable="false" aria-hidden="true" class="icon-arrow-up " viewBox="0 0 26 28"> <path d="M25.172 15.172c0 0.531-0.219 1.031-0.578 1.406l-1.172 1.172c-0.375 0.375-0.891 0.594-1.422 0.594s-1.047-0.219-1.406-0.594l-4.594-4.578v11c0 1.125-0.938 1.828-2 1.828h-2c-1.062 0-2-0.703-2-1.828v-11l-4.594 4.578c-0.359 0.375-0.875 0.594-1.406 0.594s-1.047-0.219-1.406-0.594l-1.172-1.172c-0.375-0.375-0.594-0.875-0.594-1.406s0.219-1.047 0.594-1.422l10.172-10.172c0.359-0.375 0.875-0.578 1.406-0.578s1.047 0.203 1.422 0.578l10.172 10.172c0.359 0.375 0.578 0.891 0.578 1.422z"></path> </svg> Back to Top </span> </a> </main> <aside class="box box-icon box-space-above" id="helpimprove" style="grid-column: 2 / 8; grid-row: 3"> <header class="box-h box-h-icon box-h-space-above box-h-icon"> <svg focusable="false" aria-hidden="true" class="icon-comments" viewBox="0 0 28 28"> <path d="M22 12c0 4.422-4.922 8-11 8-0.953 0-1.875-0.094-2.75-0.25-1.297 0.922-2.766 1.594-4.344 2-0.422 0.109-0.875 0.187-1.344 0.25h-0.047c-0.234 0-0.453-0.187-0.5-0.453v0c-0.063-0.297 0.141-0.484 0.313-0.688 0.609-0.688 1.297-1.297 1.828-2.594-2.531-1.469-4.156-3.734-4.156-6.266 0-4.422 4.922-8 11-8s11 3.578 11 8zM28 16c0 2.547-1.625 4.797-4.156 6.266 0.531 1.297 1.219 1.906 1.828 2.594 0.172 0.203 0.375 0.391 0.313 0.688v0c-0.063 0.281-0.297 0.484-0.547 0.453-0.469-0.063-0.922-0.141-1.344-0.25-1.578-0.406-3.047-1.078-4.344-2-0.875 0.156-1.797 0.25-2.75 0.25-2.828 0-5.422-0.781-7.375-2.063 0.453 0.031 0.922 0.063 1.375 0.063 3.359 0 6.531-0.969 8.953-2.719 2.609-1.906 4.047-4.484 4.047-7.281 0-0.812-0.125-1.609-0.359-2.375 2.641 1.453 4.359 3.766 4.359 6.375z"></path> </svg> <h2>Help improve this page</h2> </header> <div class="box-i"> <p>Please share your ideas, suggestions, or comments via e-mail to the publicly-archived list <a href="mailto:public-agwg-comments@w3.org?subject=%5BUnderstanding%20and%20Techniques%20Feedback%5D">public-agwg-comments@w3.org</a> or via GitHub</p> <div class="button-group"> <a href="mailto:public-agwg-comments@w3.org?subject=%5BUnderstanding%20and%20Techniques%20Feedback%5D" class="button"><span>E-mail</span></a> <a href="https://github.com/w3c/wcag/issues/" class="button"><span>Fork & Edit on GitHub</span></a> <a href="https://github.com/w3c/wcag/issues/new" class="button"><span>New GitHub Issue</span></a> </div> </div> </aside> </div> <footer id="wai-site-footer" class="page-footer default-grid" aria-label="Page"> <div class="inner" style="grid-column: 2 / 8"> <p><strong>Date:</strong> Updated 02 April 2024.</p> <p><strong>Developed by</strong> <a href="https://www.w3.org/groups/wg/ag/participants">Accessibility Guidelines Working Group (AG WG) Participants</a> (Co-Chairs: Alastair Campbell, Charles Adams, Rachael Bradley Montgomery. 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