For those who may have a bit of a hearing impairment, let me make it
very clear. In my subject, I'm saying DOM, D O M, not balm,
b A L M. Although some may call DOM the balm. LOL! And here
therefore lies the reason for my post this morning. - I fully realize that
this is somewhat a subjective topic, and that everyone will have his or
her own opinions on the matter. It is therefore my hope, that you, the
reader, have an open and civil mind, and observe this question from all
angles before making your response statement on list. I do not want to see
this grow to a heated war debate. Anyone who would like to publish this on
their website, or wherever is welcome to do so as long as you give credit
back to me.
First off, what is DOM?
DOM, Document Object Model, without getting too technical, is one way
in which assistive technology such as screen readers obtain information
from one's computer screen. When we load a website in our browser of
choice, for example, some screen readers use the DOM functionality to draw
a representation of the content on the screen.
So, what does this mean to us non-techies?
Put simply, though I am not particularly sure of the exact workflow
which occurs behind the scene, what I can tell you is this. Often times,
more than not, this approach requires the assistive technology sitting in
between the user and the web browser to redraw, as some would say, the
entire HTML content in completion. The reason that the word "redraw" is
used is because essentially, this is exactly what is happening.
Once a website is loaded, a certain amount of memory is allocated
aside where the website in question may be rendered. There are a few
advantages to this, however there are also some huge setbacks.
Beauty and the Beast
One of the advantages which probably appears to be fairly obvious
from an outsider's perspective is that this will allow assistive
technology to use certain methods to gather the web content and then
present the material in an easy, robust, and sensably accessible manor. As
the writer of this post, let me assure all of you... I definitely see the
side of this argument.
Here's a practical example of DOM.
Let's assume, for just a moment, that you have loaded a website in
the browser of your preference, be it Firefox, Internet Explorer, Chrome,
etc.
On this particular page, there are links which visually appear as
horizontal tabs extending across the top of the page. These tabs include
the following:
- Home
- About Us
- Blog
- Shop
- Support
- Contact Us
To fully understand how this works, I encourage you to read the
following part of this e-mail by using your down arrow key, and reading
line by line individually. Here is what you will see. Remember before I go
any further with this, all of these links visually appear as one strip of
horizontal tabs running across the top of the web page.
Link Home
Link About Us
Link Blog
Link Shop
Link Support
Link Contact Us
Here's another example.
You have a short form on a website. This form asks for your first
name, your last name, and your e-mail address. Here's how DOM most likely
would reinterpret this. Again, please read this line by line.
Please fill out the following form so we may keep in touch.
First name
Edit
Last name
Edit
E-mail
Edit
Submit button
Clear form button.
First example without DOM
Read this line by line, and make sure this window with my message is
maximized before doing so.
Link home, Link About Us, Link Blog, Link Shopt, Link Support, Link
Contact Us.
Second example without DOM
Please fill out the following form so we may keep in touch.
First name Edit
Last name Edit
E-mail Edit, Submit: button, Clear form: Button.
The difference
As you can see in the above four illustrations, the first two
examples were rendered in such that each link/form control was on its own
line. This is why I asked you to read line by line, as doing a say-all,
you never would have most likely caught this. So, in other words, let's
make this really easy in plain english.
Refer back to my very first example where we had the tabs which are
being represented as hyperlinks. As you recall, I said that they all went
horizontally from left to right across the top of the page.
The problem is, DOM renders each element, for lack of better word, as
its own separate item. For this reason, each element is on its own
dedicated line of text. This is why each link is seeming to appear on its
own line by itself. The truth is, these links in all actuality are not on
multiple lines. They are actually expanding across the entire marginal
width of the screen. Are you starting to see where this could be a
potential problem?
The second example is slightly less annoying, however the point still
stands in existance.
We have a form. If you've ever seen how a form generally looks on a
print sheet of paper, you'll note that most form field labels such as
first name, last name, etc. go down the left side of the sheet of paper.
Then, horizontally aligned beside these field labels is the data
value.
For example, I might have a form printed out which I sign for a Hippa
release at my doctor's office. The first field may say, "Name". Out to the
immediate right of this will be either a line, or a box. It just depends
on how the form is designed, but the over all point is, there will be a
second column to the immediate right of where it said, "First name". This
is where I would write, "Christopher (Middle name) Gilland. Obviously,
some of you may know my middle name, but for privacy sake, I'm not
including it here.
Given how the above physical print paper illustration is formatted,
as most forms online or not would be, does it really make sense to have
the form field, then the data directly below? No. It doesn't.
Look at my above second example without DOM. Notice that the edit box
for all three fields is now actually rendering exactly as it would be
visually on the screen. The boxes are to the immediate right of the
fields, on the same line. Doesn't that just naturally feel better in your
mind, and make more sense? It definitely should to most people.
Finally, we have both the submit, and the clear vbuttons.
Does it make sense to you that they'd both be virtically stacked one
on top of the other? It certainly doesn't to me! In fact, to me, I'd even
go so far as to say it seems absolutely gross! Maybe I am more a
visual learner, but even if I wasn't, this doesn't logically
compute. However, this is exactly how DOM is rendering it... One button,
and one element per line.
Helping the sighted to guide you
So why is this such a vbig deal? Call me a perfectionist, but let's
assume for just a moment that you're on the phone with a customer service
representative. They tell you to click the contact us tab located in the
upper right corner of the page. This would be a very poor website design,
and to any web debvs on here, please for the love of god, take this in
consideration! I can't tell you though how many times I've seen this. A
web designer will put a contact link at the top of the page which has a
form to e-mail them. Further down the page, they have another contact link
within the actual main body's content. The difference however is, in this
second link, though named identically the same thing, "Contact Us", this
second link doesn't direct the visiter to a contact form, but instead
gives a phone number, fax number, and possibly a postal address. Totally
unacceptable in my view! All this should be consolidated on the one
contact page at the top of the screen. This however still proves my point,
and like I said, I've seen this more times than I could count, and would
gbe rich if I had a dollar for every time I have. OK, so, you now arrow
through the page, or do an NVDA find to locate the Contact link. Heck, you
might even do NVDA+F7 to bring up your links list. And believe me, though
I'm directing this more as an NVDA thing, NVDA isn't the only screen
reader which can use the DOM method. JAWS, for example, is incredibly! and
I do mean, incredibly! notorious for this. Now, think about this a minute
with this really convoluted scanareo regarding the contact link. - How are
you going to know which contact link to press enter on to open the contact
form, if you're in DOM navigation? Exactly! - You won't. It would be hit
and miss.
Now, let's take this same situation without DOM mode.
In this environment, for lack of better word, you would observe both
via audible speech, as well as via braille output if you have a display,
that the first "Contact us" link is on the far right edge of the screen.
You'd know this as you'd see the other links like Home, About us, Blog,
etc. on the same line but to the immediate left before it. Does this make
sense what I'm saying?
The bottom line
Regardless if you choose to use DOM or not is not something anyone
should decide for an individual. If you are coming from a screen reader
like JAWS as I have, you definitely may find turning off DOM navigation to
be extremely awquard at best. I'd even go as far as to say that it may
drive you absolutely crazy at first, and make your web browsing experience
seem dreadful. I would however seriously encourage people to at least give
it a try for a few days without DOM navigation. Inevitably, if you're not
used to it, it's going to take some getting used to, however if you're
anything like me, I feel that eventually, you will really start to see the
benefits of not using DOM. DOM is great in my opinion, don't get me wrong,
but if you want, or need in a mission critical environment to have an
exact representation of the content, then fact is fact, you're not going
to get it with DOM mode, end of the story, it's just not gonna happen,
period. You might as well just accept it. The other thing to also realize
is, you are taking up unnecessary memory/processor power to render things
differently as an offline model. Granted, OK, it may not be much, but
that's not the point. It's still taking up what to some would be
considered as unnecessary resources.
What are your thoughts?
Do you use DOM? If not, I'd be interested in your reasons why
not.
Chris.
