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.
