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(m) When a web page
requires that an applet, plug-in or other application be present on the client
system to interpret page content, the page must provide a link to a plug-in or
applet that complies with §1194.21(a) through (l).
Why is this provision necessary?
While most web browsers can easily read HTML and display it to the user, several
private companies have developed proprietary file formats for transmitting and
displaying special content, such as multimedia or very precisely defined
documents. Because these file formats are proprietary, web browsers cannot
ordinarily display them. To make it possible for these files to be viewed by web
browsers, add-on programs or "plug-ins" can be downloaded and installed on the
user's computer that will make it possible for their web browsers to display or
play the content of the files. This provision requires that web pages that
provide content such as Real Audio or PDF (Adobe Acrobat's Portable Document
Format) files also provide a link to a plug-in that will meet the software
provisions. It is very common for a web page to provide links to needed
plug-ins. For example, web pages containing Real Audio almost always have a link
to a source for the necessary player. This provision places a responsibility on
the web page author to know that a compliant application exists, before
requiring a plug-in.
How can plug-ins and applets be detected?
Plug-ins can usually be detected by examining a page's HTML for the presence of
an <OBJECT> tag. Some plug-in manufacturers, however, may require the use of
proprietary tags. Like plug-ins, applets can also be identified by the presence
of an <OBJECT> tag in the HTML source for a web page. Also, an <APPLET> tag may
also signal the inclusion of an applet in a web page.
Back
Applets and Plug-ins
- Relevance to Accessibility
- While most web browsers can easily read HTML and
display it to the user, several private companies have developed proprietary
file formats for transmitting and displaying special content, such as
multimedia or very precisely defined documents. Because these file formats are
proprietary, web browsers cannot ordinarily display them. To make it possible
for these files to be viewed by web browsers, add-on programs or "plug-ins"
can be downloaded and installed on the user's computer that will make it
possible for their web browsers to display or play the content of the files.
This provision requires that web pages that provide content such as Real Audio
or PDF (Adobe Acrobat's Portable Document Format) files also provide a link to
a plug-in that will meet the software provisions. It is very common for a web
page to provide links to needed plug-ins. For example, web pages containing
Real Audio almost always have a link to a source for the necessary player.
This provision places a responsibility on the web page author to know that a
compliant application exists, before requiring a plug-in.
- 508 Software (Subpart
B)(1194.21)
- 508 Web (Subpart B)(1194.22)
- (m)
When a web page requires that an applet, plug-in or other
application be present on the client system to interpret page content, the
page must provide a link to a plug-in or applet that complies with §1194.21(a)
through (l).
- 508 Functional Performance
(Subpart C)
- (a)
At least one mode of operation and information retrieval that does not
require user vision shall be provided, or support for assistive
technology used by people who are blind or visually impaired shall be
provided.
- (b)
At least one mode of operation and information retrieval that does not
require visual acuity greater than 20/70 (when corrected with
glasses) must be provided in audio and enlarged print output that works
together or independently. In the alternative, support for assistive
technology used by people who are blind or who have low vision must be
provided.
- (c)
At least one mode of operation and information retrieval that does not
require user hearing must be provided, or support for assistive
technology used by people who are deaf or hard of hearing shall be provided.
This provision is met when a product provides visual redundancy for any
audible cues or audio output. If this redundancy cannot be built-into a
product then the product shall support the use of assistive technology.
- (d)
Requires that audio information important for the use of a product, must be
provided in an enhanced auditory fashion by allowing for an
increase in volume and/or altering the tonal quality or increasing the
signal-to-noise ratio.
- (e)
At least one mode of operation and information retrieval which does
not require user speech must be provided, or support for assistive
technology shall be provided. Most products do not require speech input.
However, if speech input is required to operate a product, this paragraph
requires that at least one alternative input mode also be provided. For
example, an interactive telephone menu that requires the user to say or press
"one" would meet this provision.
- (f)
At least one mode of operation and information retrieval that does not
require fine motor control or simultaneous actions and which is
operable with limited reach and strength must be provided.
- 508 Information, Documentation, and Support
(Subpart D)
- None or In Progress of Mapping
- Comparison
- In Progress
- @@ Katie:
Needs Work --- SEE: Plug-ins @@
- UAAG 1.0 Requirements & Priority
- 2.1
Render content according to specification (Both (g) and
(h))
- Render content according to
format specification (e.g., for a markup language or style sheet).
- When a rendering requirement of
another specification contradicts a requirement of the current document, the
user agent may disregard the rendering requirement of the other
specification and still satisfy this checkpoint.
- Rendering requirements include
format-defined interactions between author preferences and user
preferences/capabilities (e.g., when to render the "alt" attribute in HTML,
the rendering order of nested OBJECT elements in HTML, test attributes in
SMIL, and the cascade in CSS2).
- Who benefits: Users with disabilities
when specifications include features that promote accessibility (e.g.,
scalable graphics benefit users with low vision, style sheets allow users to
override author and user style sheets).
- [Priority
1]
-
- 3.4
Toggle scripts
- Allow configuration not to
execute any executable content (e.g., scripts and applets).
- In this configuration, provide an
option to alert the user when executable content is available (but has not
been executed).
- The user agent is only required
to alert the user to the presence of more than zero scripts or
applets (i.e., per-element alerts are not required).
- Who benefits: Control of executable
content is particularly important as it can cause the screen to flicker, since
people with photosensitive epilepsy can have seizures triggered by flickering
or flashing, particularly in the 4 to 59 flashes per second (Hertz) range.
Peak sensitivity to flickering or flashing occurs at 20 Hertz.
- [Priority
1]
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