![]() Set its style.display to "none" to control the presentation aspect of the child content.Return the element id where the style will be applied.If it is not supported the function will end, and the content will be revealed, establishing graceful degradation of the script.Writing the else if() conditional statement of the functionīetween the else if parentheses, place the document.getElementById expression to test if it is supported by the user agent. Instruct the parent to remove all child content within it.Declare the container element and identify its id value as the external, unobtrusive "hook" to the markup.If it is not supported the function progresses to the else if() conditional statement and tests it.If it is supported the function will continue, and the content will remain hidden.This tests to see if it is supported by the user agent. Writing the if() conditional statement of the functionīetween the if parentheses, place the document.removeChild expression. In this section we'll build the two main sections of the external noscript.js JavaScript file. Reset Building the unobtrusive DOM/JavaScript Lorem ipsum dolor sit amet, consectetuer adipiscing elit. The following HTML markup sample illustrates this: Place all elements and content to be hidden while JavaScript is enabled within the.This sets the unobtrusive hook to the external JavaScript noscript() function. Give the opening tag of the element an id attribute with a value of "noscript", that is.In the element tag of the web page, insert a element containing the path to the external noscript.js file.Ĭreate a element within the element tags to contain the hidden content.In this section we'll build the HTML markup portion of the example. ![]() Important note: If the ability to hide the alternative content with JavaScript does not exist, the browser/user agent will be able to render the content ensuring accessibility and graceful degradation. This ensures graceful degradation of the script. When JavaScript is disabled the function no longer works, and the alternative content in the markup is revealed. ![]() If the user agent cannot interpret the JavaScript expressions, the alternative content in the markup is revealed. When JavaScript is enabled, the external function keeps the alternative content hidden. Associate the hook with an external JavaScript function, which sets up a parent-to-child relationship between the container and its content.Insert an unobtrusive JavaScript "hook" via an id attribute value in the parent container's opening tag.So, how can behavior intended by the HTML element be enabled in these antiquated/partially-capable JavaScript user agents? The workflow is as follows: If the user agents among your audience are unpredictable, however, replacing the element with another mechanism becomes significant. If your writing is targeted at modern, standards-based, compliant, and fully capable JavaScript user agents, employing the element is no problem. This has an impact on the accessibility of the content. User agents with partial/antiquated JavaScript capabilities however interpret the element correctly and do not show the content, but when JavaScript is disabled also do not show the content - it never gets rendered. User agents that do not support JavaScript will display the content within it. ![]() Modern user agents with JavaScript enabled will hide content contained within the tags, and reveal it when JavaScript is disabled. In his book "ppk on JavaScript", Peter-Paul Koch points out that the HTML element has a limitation. Palinkas, Senior Technical Writer, Information Architect © 2015 Contents Introduction Solving the problem Building the HTML markup Building the unobtrusive DOM/JavaScript SummaryĬode examples in this document are editable.Īfter editing, click Reset to restore the original code. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |