iframe-like within specific id or class using javascript? - javascript

On iframe, it show full page.
But I want an iframe-like which showing only within specific id or class.
(So, it must be not the usual iframe. I think javascript is the closest solution to this.)

If I understand it correctly, this doesn't have much to do with the Iframe itself, but more with your selectively setting some parts of your page to visible or invisible, depending on how the page is called?
You could make your page modal, for example by adding a querystring parameter ?viewmode=full or ?viewmode=reduced and then your page would only show certain areas depending on the value of this parameter. In your Iframe you'd set it to viewmode reduced to only see those areas you want to see.
As to how to show only specific areas, you can either do this server-side (hide those Panels that you don't want to see) or client-side with jQuery (show only those divs that have class X). It depends on the structure of your specific page which solution is going to be easier for you.

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HTML Semantics - Button acting as an anchor

I'm mainly interested in the a11y aspects
So as you might be aware, sometimes you might wish to have a button that acts as an anchor.
These are 4 ways (I can think of) of approaching this issue:
1. Button inside an anchor element
<button>Button</button>
2. Anchor inside button element
<button>Button</button>
<!-- Also should it be a href or button onclick (?) -->
3. Anchor styled as a button (without a button element)
<a class="buttonLike" href="//redirection">Button</a>
4. Button acting as a redirection (without an anchor element):
const button = document.getElementById('button')
button.addEventListener('click', () => {
window.location.href = "//redirection"
})
<button id="button">Button</button>
I've tried to find an answer to this myself. Closest I could find was this excerpt:
According to the MDN anchor spec, which states the following:
Anchor elements are often abused as fake buttons by setting their href to # or javascript:void(0) to prevent the page from refreshing, then listening for their click events .
These bogus href values cause unexpected behavior when copying/dragging links, opening links in a new tab/window, bookmarking, or when JavaScript is loading, errors, or is disabled. They also convey incorrect semantics to assistive technologies, like screen readers.
Use a <button> instead. In general, you should only use a hyperlink for navigation to a real URL.
Unfortunately this doesn't help me too much. Basically all it states is you should not use the third approach (anchor styled as a button) if you don't mean to provide a real link to it, which is not what this question is about.
Is there any official WCAG on this subject matter that I was unable to find or?
Option 1 is not valid HTML.
Option 2 is not valid HTML.
Option 3 is the correct choice here.
Option 4 is semantically incorrect.
Semantics are one of if not the most important aspects of accessibility.
There are two things at play which dictate option 3.
The first is that an anchor should be used only to jump to sections and to navigate between pages.
The second is that a button should perform actions on the same page.
Now if you want to style a call to action link to look like a button that is fine but make sure you use the correct semantics, but make sure that CTA leads to a new page or it isn't semantically correct.
And although it is swearing on StackOverflow to mention SEO, a hyperlink rather than a JavaScript redirection will be far better.
The first and second rules of ARIA say:
1st rule : If you can use a native HTML element [...] then do so
2nd rule : Do not change native semantics, unless you really have to.
Interactive elements like a and button can't contain other interactive elements:
The a element may be wrapped around entire paragraphs, lists, tables, and so forth, even entire sections, so long as there is no interactive content within (e.g. buttons or other links).
So, as what you want to do is linking to a page, your third solution is obviously the only one correct.
I think you might have confused the "bogus" stagement which refers to your 4th example.
From my little experience with Accessibility and semantics there is no "one size fits all". It really depends on your priorities and the user experience you are aiming for.
A <button> gets all the accessibility goodies from the browser automatically: Being selected or pressed using the tab or spacebar/enter keys.
A <a> element is a link, links are meant to be used as links or anchors within a page.
Anchors are not as important in comparison to a button within a page. From a user experience point of view; a button is used by people to interact with a UI, either to confirm or make the UI do something. Pressing a button provides a different feedback compared to a link. Anchor links on the other hand help a user with finding content within a page.
Again, it really depends on what you are trying to do:
Is this a terms page or an article? Then list your anchor links without any button-like styling
Does this a link that has to look as a button so users find it easier to spot or interact? Then style it as a button without it being actually a <button>.

Is there a way to determine if CSS class is active in HTML page?

this is more a curiosity of mine, I don't know if it's something possible.
If I am inside a HTML page, is there a way to quickly determine if a CSS class is active inside that page?
I explain better, let's say I am inside a website with a list of different users and near their avatar I may have a green badge for online users, while others has grey badge.
If this list is really long, is there a way to programmatically (or at least quicker than scrolling and looking by myself) detect which users are online?
I thought they have a different active CSS class but I don't know how to look for it.
Thanks
NOTE: I know how to detect an element, but if there's a list of elements I need to know which of them has a particular class active
you can use (inspect) in chrome ctrl+shift+i in inspect element you can see which css is active or not right side
https://developer.mozilla.org/en-US/docs/Web/API/Document/querySelector
Placing the code below within your developer console should display the length of the existing classNames if they exist.
const classes = document.querySelectorAll(".className");
console.log(className.length);
You should then be able to navigate the classes for the relevant information by navigating the object trees returned for each object found by the querySelectorAll method.
But there may be times where this may not be the true count to the data set.
For example, if the data is dynamically loaded during page scrolling. You can then add an iterator loop to detect when you have reached the bottom of the page and push to the classes array.

Javascript best practices - Hide element in DOM or Generate DOM element

I've a question about best practices in javascript.
I've a dropdown menu with some statuts. If the statut is : external, I want to display a form. I don't know the best way to do this. Do i need to hide a DIV from the DOM and display him when i need it or do i need to generate my form dynamically in jquery and make a call ajax to populate some data.
It really depends on your application. If you already have a lot of elements in the DOM, and the likelyhood of actually needing to show this form is low, you may want to add it later (using ajax) because in most cases you don't need it anyway. However, if your DOM load is light, and in most cases the form will be shown, you make want to have it ready and hidden so that is can be quickly shown.
There is also a middle ground where you can "lazy load" it (using javascript on page load), and keep it in a json object until it is ready to be used. This will keep your DOM responsive, and give the added benefit of a quicker load of the form.
it depends on the probability of user clicking on that element and number of elements already present in the DOM. I suggest to create form runtime whenever user performs action instead of hiding it. There are some browser plugins which shows all hidden elements in a page.
Unless your page is unusually large already or there are a lot of different forms like this that could be used from the same page, putting the HTML into the page and just starting out with it hidden gives you the advantage that all your markup is in one place (in the HTML file that represents your page) and can more easily be centrally maintained that way.
When you start putting markup into your javascript, you split up the maintenance of the markup between both the HTML of the page and the HTML that is embedded into your page.
If, on the other hand, you had a lot of these forms that were all slightly different that could all be used from the same page, then it gets messy to pre-specify all possible combinations of the form in the original HTML and you would probably be better off dynamically generating it via javascript or perhaps generating it from a template with slight modifications.

Advice about using Tabindex and javascript/jquery to make "tabbing" easier

I'm making a large and complex application and I need to set tabindexes to help user navigate through the pages. This is a private application so I don't have restriction about (ab)using javascript (jquery).
I currently have these questions.
1) How do you force with javascript (jquery) the browser to move the cursor inside a specific textbox as soon as a page has loaded? I noticed that often browsers don't automatically put the cursor inside the first tabindexed input. I want a surefire way that forces it there no matter what.
2) Some fields that activate ui enanchement (namely jquery ui datepicker) have problems with tabbing (like having to push tab two time to go away from it), is there any way to avoid this?
3) How do you read and set tabindex with jquery? I have some fields that get hidden/shown based on user action and they should be able to "give" their tabindex to other fields if they get hidden, is this a problem, does the browser still consider a tabindex after the page has loaded?
Thank you very muchh
To put focus on a specific textbox, do this (assuming textbox id is #firstBox): $('#firstBox').focus(); See more examples here: How do you automatically set the focus...
Not particularly because the DatePicker is also its own UI, so it has various objects within it that can be focused on (which is what tabbing picks up on).
Actually, now that I've thought about it, if you hide a field (AKA, "hidden") it will not have a tabindex and the other tabs will fall in line with what is defined for the browser (typically top to bottom, left to right order). You shouldn't have to worry about setting the tabindex manually.

Highlighting active panel in CSS without JavaScript

I'm building something similar to this - http://www.impressivewebs.com/demo-files/content-switcher/content-switcher.html
I wondered if anyone had any ideas as to how I can show the current panel in the navigation WITHOUT using JavaScript - pure CSS.
I'm fairly confidant it's not possible but I thought I'd ask anyway.
Just to clarify...
You'll notice that when you click a link on this page - http://www.impressivewebs.com/demo-files/content-switcher/content-switcher-javascript.html the link you just clicked on highlights to inform the user which panel they're looking at. That's what I want to do in CSS.
It's possible, believe it or not, it's just really tricky. This should get you started: http://thinkvitamin.com/design/css/how-to-create-a-valid-non-javascript-lightbox/ The key bit is captured in this quote:
I'm sure you are all aware of linking to an an element on the same page with the use of the ID attribute and how it works. However, you may not have known that linking to an element that is hidden off the page causes the element to be "pulled" into view as opposed to the window jumping down to that element.
So basically, you'd put all of your slides off-page and then have the numbered links use anchors to pull those into view. Your use case should be a bit simpler than the one she's doing, since you don't have to dim out the rest of the page.
What you need to do is to put what you need to slide inside a container with fixed size and "overflow" property set to hidden.
Then, inside this container, you put your "slidable" contents inside a list of anchor elements with "display" set to block and size the same of the container.
If, from a link on the page, you call one of the anchors in the list, the element with the correspondent anchor name will automgically show up..
simple as that.

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