Bear Bibeault

Your questions is sort of like:
"I want to build a Thing."
"What is the Thing supposed to do?"
"I dunno, I just want to build it."

If you know how to set response headers, you know how to implement HEAD. Fetch the same information you would fetch for a GET, and just return the headers.

Read up on CORS to see what headers should be returned for a CORS OPTIONS request.

For TRACE:

The HTTP TRACE method is normally used to return the full HTTP request back to the requesting client for proxy-debugging purposes. An attacker can create a webpage using XMLHTTP, ActiveX, or XMLDOM to cause a client to issue a TRACE request and capture the client's cookies.

Note the security vulnerability.

Implementing them is as simple as adding the appropriate doXXX methods to the servlet. What goes in the method depends on what you want to do with them.

HEAD is used to return body-less information regarding a resource, OPTIONS is most often used for CORS. TRACE is generally used for debugging.

It's actually rare for those to be implemented in most servlets -- what usage are you envisioning using these HTTP methods for? CORS?

Additionally you'll need to precede all paths with the context path of the application. It can be obtained in a JSP with the EL expression: ${pageContext.request.contextPath}

Not really trying to dump on Angular here, but trends do not support that it is "one of the most popular" frameworks.

Sites with actual metrics like npm trends show it is lagging badly behind other framework/libraries (I'm not going to get pulled into the framework vs library debate) such as React.

Metrics: yearly trend shows Angular pretty flat (in fact, slightly downward, 560K to 545K, with React rising from 8.2M to almost 12M.

Use the debugging inspector to see how the DOM elements differ from when they are the expected, to when they are wrong. That should give you a thread to pull to figure out what's awry.

This has nothing at all to do with Angular. It's straight-forward HTML (hence it has been moved to the HTML forum).

You should use CSS for styling, not HTML attributes. And, if you want the row background colored, put the styling on the <tr> element.

You don’t need to keep track of touched values yourself; antd will do that for you and pass the information to the form handlers. antd also has form validation that you can leverage.

Check out the examples on the Form page for details. Granted, the antd documentation is not the best, but you should be able to find what you are looking for.

Welcome David Griffiths and Dawn Griffiths!

Why are you not setting up the change handler in the same code that creates the element?

In general $('some-selector') evaluates to the empty set whenever the selector matches nothing. So attempting to establish a handler for elements that don't exist yet won't work. The best approach is to establish the handler for new elements when the element is created.

If for some reason that is not possible, then event delegation can come into play, but that's only an option if all others fail.

Does your code to establish the change handler execute after the DOM elements have been created?

XHTML is dead and buried.

Be aware that rotating is just a visual transform, and does not affect the width calculation of an element. So you likely need to get the containers the width you want according to the length of the text, rotate, and the adjust width accordingly.

The quadratic equation, or some trig, might be useful for approximating the needed width based on number of characters.

What is the desired appearance?

But is there really a problem? I mean, the whole point of rotating the headers is to be able to keep the columns small, no?