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.
