Frontend

Front-end web development is the development of the graphical user interface of a website through the use of HTML, CSS, and JavaScript so users can view and interact with that website.

Restrict Access to a JavaScript Application Embedded via an iframe

One common way to embed a JavaScript application in a web page is using iframe. Assuming the application is accessible from https://example.com/my-app and the embedding page is https://example.com/content, the embedding code in the embedding page would look like this: <body>  <iframe src="https://example.com/my-app"><iframe>  </body> This approach works for an application written in either vanilla JavaScript or any frameworks, like React or Vue. However, this risks two potentially undesired effects: Other websites may embed this application with iframe without permission. The visitor may visit the embedded iframe directly and thus have skipped the content of the parent page. This post discusses solutions that address these two problems. ...

Set an Attribute Without Value in JavaScript

Often, we see HTML code snippets that set an attribute of an element without any value, like the following: <button id="my-button" disabled>I'm a button</button> In the HTML code snippet above, the id attribute has a value of "my-button", while the disabled attribute is present without any specified value. Many of us may wonder: How can I add such an attribute without a value like disabled above in JavaScript? The answer is probably trickier than most of us may have thought: This is impossible, and you may have been misled by the appearance of the HTML code. ...

Maintaining an Open Source JavaScript Project? Help Dependents Retain Notices

This post is not legal advice. By reading this post, you agree and acknowledge that this post does not advise you on how to properly license your work and you would not rely on this post to license your work; that this post does not advise licensees of open source work on how to comply with the licenses; and that this post only provides technical guidance on programming tasks that are common to licensing open source projects. Most popular open source licenses require redistributors to retain the copyright and permission notices, among other things. For example, even the brief MIT License explicitly requires so: …The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software… However, without any automation, this simple task is not so simple for a browser (front-end) JavaScript project: Tens and even hundreds of open source dependencies are often bundled and minified into a single .js file. Then, this .js file is commonly distributed to browsers via the Internet. As maintainers of open source JavaScript projects, what can we do to make retaining copyright and permission notices easier for dependent browser JavaScript projects? ...

Test the Presence of a Material UI Icon in Jest/Vitest

Testing the presence of a Material UI Icon in Jest/Vitest can be done by using the Testing Library. First, in the production code, assign a titleAccess attribute to the icon. For example, if the icon of interest is AddIcon, the code would look like: <AddIcon titleAccess="My Add Icon" /> This attribute would also surface to the user interface. ...